 
Brief Guide to Doing SPICE Hands-On Lessons Using WGC
===========================================================================
 
   March 01, 2023
 
 
Overview
--------------------------------------------------------
 
   This guide provides brief instructions on how to do SPICE ``Remote
   Sensing'' (CASSINI, ExoMars 2016, KPLO, and BepiColombo MPO), ``In-situ
   Sensing'' (CASSINI and BepiColombo MPO), ``Geometric Event Finding''
   (Mars Express, ExoMars 2016, KPLO, and BepiColombo MPO), and ``Binary
   PCK'' hands-on lessons using the SPICE WebGeocalc (WGC) tool.
 
   Instructions for each lesson are provided in a separate section below.
   They follow the lesson steps and individual assignments within each
   step, indicate which WGC computation panels (``calculations'') should be
   used and what inputs should be entered or selected in these
   calculations, and what key outputs should be expected from WGC. Where
   applicable, they indicate that a particular quantity computed in the
   lesson cannot be computed by WGC.
 
 
WGC and WGC Tutorial URLs
 
   WGC servers at NAIF can be accessed at:
 
      https://wgc.jpl.nasa.gov:8443/webgeocalc/#NewCalculation
      https://wgc2.jpl.nasa.gov:8443/webgeocalc/#NewCalculation
 
   WGC server at ESAC can be accessed at:
 
      http://spice.esac.esa.int/webgeocalc/#NewCalculation
 
   Project-specific WGC servers (e.g. for KPLO) can be accessed at the URLs
   provided during the class.
 
   The WGC tutorial and examples are linked from the WGC introduction page
   on the NAIF server:
 
      http://naif.jpl.nasa.gov/naif/webgeocalc.html
 
 
``CASSINI Remote Sensing'' Hands-On Lesson Using WGC
--------------------------------------------------------
 
 
Kernels Used
 
   Use the ``SPICE Class - CASSINI Remote Sensing Lesson Kernels'' kernel
   set appearing near the bottom of the ``Kernel selection:'' menu to do
   all steps in this lesson.
 
 
Time Conversion (convtm)
 
   To compute ET seconds past J2000, specify/select the following inputs in
   the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 jun 11 19:32:00
      Output time system        TDB
      Output time format        Seconds past J2000
 
   WGC will return the following ET seconds past J2000:
 
      140254384.184620
 
   To compute calendar ET in the default format, specify/select the
   following inputs in the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 jun 11 19:32:00
      Output time system        TDB
 
   WGC will return the following calendar ET time string:
 
      2004-06-11 19:33:04.184625 TDB
 
   To compute calendar ET in a custom format, specify/select the following
   inputs in the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 jun 11 19:32:00
      Output time system        TDB
      Custom format             YYYY-MON-DDTHR:MN:SC ::TDB
 
   WGC will return the following calendar ET time string:
 
      2004-JUN-11T19:33:04
 
   To compute spacecraft clock time, specify/select the following inputs in
   the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 jun 11 19:32:00
      Output time system        Spacecraft clock (SCLK=-82)
 
   WGC will return the following SCLK time string:
 
      1/1465674964.105
 
 
Time Conversion -- Selected Extra Credit
 
   1. To compute TDB Julian Date, specify/select the following inputs in
   the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 jun 11 19:32:00
      Output time system        TDB
      Output time format        Julian Date
 
   WGC will return the following TDB time string:
 
      2453168.314631800 JD TDB
 
   5. To compute the earliest UTC time that can be converted to CASSINI
   spacecraft clock, specify/select the following inputs in the ``Time
   Conversion'' calculation:
 
      Time system               Spacecraft clock (SCLK=-82)
      Time format               Spacecraft clock ticks
      Input time                0.0
      Output time system        UTC
      Output time format        Calendar (year-month-day)
 
   WGC will return the following UTC time string:
 
      1980-01-01 00:00:00.000000 UTC
 
   6. To convert the spacecraft clock time obtained in the regular task
   back to UTC Time and present it in ISO calendar date format, with a
   resolution of milliseconds, specify/select the following inputs in the
   ``Time Conversion'' calculation:
 
      Time system               Spacecraft clock (SCLK=-82)
      Time format               Spacecraft clock string
      Input time                1/1465674964.105
      Output time system        UTC
      Custom format             YYYY-MM-DDTHR:MN:SC.### ::RND
 
   WGC will return the following UTC time string:
 
      2004-06-11T19:31:59.999
 
 
Obtaining Target States and Positions (getsta)
 
   To compute the apparent state of Phoebe as seen from CASSINI in the
   J2000 frame, specify/select the following inputs in the ``State Vector''
   calculation:
 
      Target type               Object
      Target                    PHOEBE
      Observer type             Object
      Observer                  CASSINI
      Reference frame           J2000
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      State representation      Rectangular
 
   WGC will return the following state vector, km and km/s:
 
      -119.92092897
      2194.13933986
      -57.63897986
      -5.98023114
      -2.11880531
      -0.29482213
 
   To compute the apparent position of Earth as seen from CASSINI in the
   J2000 frame and one way light time between CASSINI and the apparent
   position of Earth, specify/select the following inputs in the ``State
   Vector'' calculation:
 
      Target type               Object
      Target                    EARTH
      Observer type             Object
      Observer                  CASSINI
      Reference frame           J2000
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      State representation      Rectangular
 
   WGC will return the following position vector, km, and one way light
   time, s:
 
      353019393.12261910
      -1328180352.14030500
      -568134171.69730540
      4960.42691203
 
   To compute the apparent position of Sun as seen from Phoebe in the J2000
   frame, specify/select the following inputs in the ``State Vector''
   calculation:
 
      Target type               Object
      Target                    SUN
      Observer type             Object
      Observer                  PHOEBE
      Reference frame           J2000
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      State representation      Rectangular
 
   WGC will return the following position vector, km:
 
      376551465.27159620
      -1190495630.30282120
      -508438699.11000470
 
   Note that WGC will also compute the distance between Sun and Phoebe body
   centers, km:
 
      1348176829.09957000
 
   but it cannot convert this distance to AUs.
 
 
Obtaining Target States and Positions -- Selected Extra Credit
 
   5. To compute the position of the Sun as seen from Saturn in the J2000
   using the following light time and aberration corrections: NONE, LT and
   LT+S, manually load a JUP310 Jovian satellite ephemeris SPK from the
   generic kernels area and specify/select the following inputs in the
   ``State Vector'' calculation (except for corrections):
 
      Target type               Object
      Target                    SUN
      Observer type             Object
      Observer                  SATURN
      Reference frame           J2000
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      State representation      Rectangular
 
   and these corrections for NONE (the geometric position), LT (the
   reception light time only corrected position), and LT+S (the apparent
   position):
 
      Light propagation         No correction
 
      Light propagation         To observer
      Light-time algorithm      Newtonian
 
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
 
   WGC will return the following position vectors, km, correspondingly:
 
      367770592.36738380
      -1197330367.35880470
      -510369088.67673343
 
      367770572.92069393
      -1197330417.73307600
      -510369109.50883270
 
      367726456.16774523
      -1197342627.87914750
      -510372252.74684080
 
   Unload the JUP310 Jovian satellite ephemeris SPK before proceeding to
   the next step.
 
 
Spacecraft Orientation and Reference Frames (xform)
 
   To compute the apparent state of Phoebe as seen from CASSINI in the
   IAU_PHOEBE body-fixed frame, specify/select the following inputs in the
   ``State Vector'' calculation:
 
      Target type               Object
      Target                    PHOEBE
      Observer type             Object
      Observer                  CASSINI
      Reference frame           IAU_PHOEBE
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      State representation      Rectangular
 
   WGC will return the following state vector, km and km/s:
 
      -1982.63976162
      -934.53047112
      -166.56259513
      3.97083213
      -3.81249566
      -2.37166299
 
   To compute the angular separation between the apparent position of Earth
   and the CASSINI high gain antenna (HGA) boresight, specify/select the
   following inputs in the ``Angular Separation'' calculation:
 
      Specification type        Two directions
      Direction type 1          Position
      Target 1                  EARTH
      Target shape 1            Point
      Observer 1                CASSINI
      Light propagation 1       To observer
      Light-time algorithm 1    Newtonian
      Stellar aberration 1      Corrected for stellar aberration
      Use anti-vector 1         No
      Direction type 2          Vector
      Ray vector 2              Z axis in CASSINI_HGA frame
      Correction type 2         None
      Use anti-vector 2         No
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
 
   WGC will return the following output separation angle, deg:
 
      71.92414848
 
 
Spacecraft Orientation and Reference Frames -- Selected Extra Credit
 
   2. To compute the angular separation between the apparent position of
   Sun and the CASSINI HGA nominal boresight to find out if HGA is
   illuminated, specify/select the following inputs in the ``Angular
   Separation'' calculation:
 
      Specification type        Two directions
      Direction type 1          Position
      Target 1                  SUN
      Target shape 1            Point
      Observer 1                CASSINI
      Light propagation 1       To observer
      Light-time algorithm 1    Newtonian
      Stellar aberration 1      Corrected for stellar aberration
      Use anti-vector 1         No
      Direction type 2          Vector
      Ray vector 2              Z axis in CASSINI_HGA frame
      Correction type 2         None
      Use anti-vector 2         No
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
 
   WGC will return the following output separation angle, deg:
 
      73.12975129
 
   This angle is less than 90 degrees so the HGA is illuminated.
 
 
Computing Sub-s/c and Sub-solar Points on an Ellipsoid and a DSK (subpts)
 
   To compute the apparent sub-observer point of CASSINI on Phoebe modeled
   as an ellipsoid in the IAU_PHOEBE frame, specify/select the following
   inputs in the ``Sub-Observer Point'' calculation:
 
      Target                    PHOEBE
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      104.49789074
      45.26884577
      7.38331473
 
   Note that WCG will compute the altitude but it will be labeled
   ``Observer Distance (km)'' in the output table and will have the
   following distance, km:
 
      2084.11604205
 
   To compute the apparent sub-observer point of CASSINI on Phoebe in the
   IAU_PHOEBE frame using a DSK shape model and the nadir point method,
   specify/select the following inputs in the ``Sub-Observer Point''
   calculation:
 
      Target                    PHOEBE
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Sub-point type            NADIR/DSK/UNPRIORITIZED
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      95.37257468
      40.94817689
      6.60990270
 
   Note that WCG will compute the altitude but it will be labeled
   ``Observer Distance (km)'' in the output table and will have the
   following distance, km:
 
      2094.24215979
 
   To compute the apparent sub-solar point on Phoebe modeled as an
   ellipsoid as seen from CASSINI in the IAU_PHOEBE frame , specify/select
   the following inputs in the ``Sub-Solar Point'' calculation:
 
      Target                    PHOEBE
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      78.68071625
      76.87865160
      -21.88456729
 
   To compute the apparent sub-solar point on Phoebe as seen from CASSINI
   in the IAU_PHOEBE frame using a DSK shape model and the nadir point
   method, specify/select the following inputs in the ``Sub-Solar Point''
   calculation:
 
      Target                    PHOEBE
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Sub-point type            NADIR/DSK/UNPRIORITIZED
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      79.11113709
      77.33831624
      -22.02817575
 
 
Computing Sub-spacecraft and Sub-solar Points -- Selected Extra Credit
 
   1. To compute the apparent sub-solar point on Phoebe as seen from
   CASSINI in the IAU_PHOEBE frame using the ``Intercept: ellipsoid''
   method, specify/select the following inputs in the ``Sub-Solar Point''
   calculation:
 
      Target                    PHOEBE
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Sub-point type            Intercept: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      74.54229300
      79.60686277
      -24.87078454
 
   2. To compute the geometric sub-observer point of CASSINI on Phoebe in
   the IAU_PHOEBE frame using the 'Near point: ellipsoid' method,
   specify/select the following inputs in the ``Sub-Observer Point''
   calculation:
 
      Target                    PHOEBE
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Sub-point type            Near point: ellipsoid
      Light propagation         No correction
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      104.49708353
      45.27041148
      7.38409174
 
   3. To compute the planetocentric coordinates of the geometric
   sub-observer point of CASSINI on Phoebe in the IAU_PHOEBE frame,
   specify/select the following inputs in the ``Sub-Observer Point''
   calculation:
 
      Target                    PHOEBE
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Sub-point type            Near point: ellipsoid
      Light propagation         No correction
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Planetocentric
 
   WGC will return the following latitude and longitude, deg, and radius,
   km:
 
      3.70986500
      23.42331102
      114.12088079
 
   WGC does not allow computing planetodetic and planetographic coordinates
   on bodies that are tri-axial ellipsoids with different equatorial radii.
   Choosing the planetographic coordinates for output will result in the
   following error message:
 
      Reference frame center is not a spheroid. Planetodetic and
      planetographic coordinate representations can only be
      calculated for bodies with equal equatorial axes. The center
      body of the reference frame, PHOEBE, has equatorial axes
      that differ, 115.0 and 110.0. Use planetocentric coordinates
      instead.
 
 
Intersecting Vectors with an Ellipsoid and a DSK (fovint)
 
   To compute the Cartesian position vectors of the FOV boundary vector
   surface intercept points on the surface of Phoebe modeled as an
   ellipsoid in the IAU_PHOEBE frame, specify/select the following inputs
   in the ``Surface Intercept Point'' calculation:
 
      Target                    PHOEBE
      Front body shape          Ellipsoid
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Ray vector                CASSINI_ISS_NAC
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vectors, km:
 
      91.02635667
      67.19017758
      2.03016242
 
      89.99095003
      66.72560204
      14.73282379
 
      80.96314734
      76.64306316
      14.42662102
 
      81.99683969
      77.10572511
      1.69850758
 
   To compute the planetocentric longitudes and latitudes of the FOV
   boundary vector surface intercept points on the surface of Phoebe
   modeled as an ellipsoid in the IAU_PHOEBE frame, specify/select the
   following inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    PHOEBE
      Front body shape          Ellipsoid
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Ray vector                CASSINI_ISS_NAC
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Planetocentric
 
   WGC will return the following longitudes and latitudes, deg:
 
      36.43251123
      1.02800787
 
      36.55583078
      7.49186596
 
      43.42988023
      7.37325329
 
      43.23917363
      0.86454948
 
   Both computations above also returned the illumination angles the FOV
   boundary vector surface intercept points but these angles were omitted
   from the output shown above.
 
   To compute the Cartesian position vectors of the FOV boresight surface
   intercept point on the surface of Phoebe modeled as an ellipsoid in the
   IAU_PHOEBE frame, specify/select the following inputs in the ``Surface
   Intercept Point'' calculation:
 
      Target                    PHOEBE
      Front body shape          Ellipsoid
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Ray vector                CASSINI_ISS_NAC boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      86.39001297
      72.08919557
      8.25459687
 
   To compute the planetocentric longitude and latitude of the FOV
   boresight surface intercept point on the surface of Phoebe modeled as an
   ellipsoid in the IAU_PHOEBE frame and the illumination angles and the
   local solar time on a 24-hour clock at this point, specify/select the
   following inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    PHOEBE
      Front body shape          Ellipsoid
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Ray vector                CASSINI_ISS_NAC boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      39.84371945
      4.19587780
 
   the following incidence, emission, and phase angles, deg:
 
      18.24722120
      17.85830930
      28.13948173
 
   and the following local solar time:
 
      11:31:50
 
   To compute the Cartesian position vectors of the FOV boundary vector
   surface intercept points on the surface of Phoebe in the IAU_PHOEBE
   frame using a DSK shape model, specify/select the following inputs in
   the ``Surface Intercept Point'' calculation:
 
      Target                    PHOEBE
      Front body shape          DSK model
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Ray vector                CASSINI_ISS_NAC
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vectors, km:
 
      78.76953031
      61.56990460
      0.96393463
 
      76.58597747
      60.57892774
      13.65732587
 
      68.67722558
      71.10033236
      13.44360714
 
      73.18644320
      73.13094296
      0.93419040
 
   To compute the planetocentric longitudes and latitudes of the FOV
   boundary vector surface intercept points on the surface of Phoebe in the
   IAU_PHOEBE frame using a DSK shape model, specify/select the following
   inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    PHOEBE
      Front body shape          DSK model
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Ray vector                CASSINI_ISS_NAC
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Planetocentric
 
   WGC will return the following longitudes and latitudes, deg:
 
      38.01282665
      0.55240127
 
      38.34372978
      7.96186655
 
      45.99314861
      7.74452041
 
      44.97826691
      0.51732714
 
   Both computations above also returned the illumination angles the FOV
   boundary vector surface intercept points but these angles were omitted
   from the output shown above.
 
   To compute the Cartesian position vectors of the FOV boresight surface
   intercept point on the surface of Phoebe in the IAU_PHOEBE frame using a
   DSK shape model, specify/select the following inputs in the ``Surface
   Intercept Point'' calculation:
 
      Target                    PHOEBE
      Front body shape          DSK model
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Ray vector                CASSINI_ISS_NAC boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      74.32619282
      66.60211698
      7.24732469
 
   To compute the planetocentric longitude and latitude of the FOV
   boresight surface intercept point on the surface of Phoebe in the
   IAU_PHOEBE frame using a DSK shape model and the illumination angles and
   the local solar time on a 24-hour clock at this point, specify/select
   the following inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    PHOEBE
      Front body shape          DSK model
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Ray vector                CASSINI_ISS_NAC boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004 JUN 11 19:32:00
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      41.86284040
      4.15340347
 
   the following incidence, emission, and phase angles, deg:
 
      33.19950064
      9.22984680
      28.13948113
 
   and the following local solar time:
 
      11:39:55
 
 
``ExoMars 2016 Remote Sensing'' Hands-On Lesson Using WGC
--------------------------------------------------------
 
 
Kernels Used
 
   Use the ``SPICE Class - ExoMars 2016 Remote Sensing Lesson Kernels''
   kernel set appearing near the bottom of the ``Kernel selection:'' menu
   to do all steps in this lesson.
 
 
Time Conversion (convtm)
 
   To compute ET seconds past J2000, specify/select the following inputs in
   the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 jun 11 19:32:00
      Output time system        TDB
      Output time format        Seconds past J2000
 
   WGC will return the following ET seconds past J2000:
 
      582017589.184640
 
   To compute calendar ET in the default format, specify/select the
   following inputs in the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 jun 11 19:32:00
      Output time system        TDB
      Output time format        Calendar (year-month-day)
 
   WGC will return the following calendar ET time string:
 
      2018-06-11 19:33:09.184642
 
   To compute calendar ET in a custom format, specify/select the following
   inputs in the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 jun 11 19:32:00
      Output time system        TDB
      Custom format             YYYY-MON-DDTHR:MN:SC ::TDB
 
   WGC will return the following calendar ET time string:
 
      2018-JUN-11T19:33:09
 
   To compute spacecraft clock time, specify/select the following inputs in
   the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 jun 11 19:32:00
      Output time system        Spacecraft clock (SCLK=-143)
      Output time format        Spacecraft clock string
 
   WGC will return the following SCLK time string:
 
      1/0070841719.26698
 
 
Time Conversion -- Selected Extra Credit
 
   1. To compute TDB Julian Date, specify/select the following inputs in
   the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 jun 11 19:32:00
      Output time system        TDB
      Output time format        Julian Date
 
   WGC will return the following TDB time string:
 
      2458281.314689600 JD TDB
 
   5. To compute the earliest UTC time that can be converted to ExoMars-16
   TGO spacecraft clock, specify/select the following inputs in the ``Time
   Conversion'' calculation:
 
      Time system               Spacecraft clock (SCLK=-143)
      Time format               Spacecraft clock ticks
      Input time                0.0
      Output time system        UTC
      Output time format        Calendar (year-month-day)
 
   WGC will return the following UTC time string:
 
      2016-03-13 21:34:13.193650 UTC
 
   6. To convert the spacecraft clock time obtained in the regular task
   back to UTC Time and present it in ISO calendar date format, with a
   resolution of milliseconds, specify/select the following inputs in the
   ``Time Conversion'' calculation:
 
      Time system               Spacecraft clock (SCLK=-143)
      Time format               Spacecraft clock string
      Input time                1/0070841719.26698
      Output time system        UTC
      Custom format             YYYY-MM-DDTHR:MN:SC.### ::RND
 
   WGC will return the following UTC time string:
 
      2018-06-11T19:32:00.000
 
 
Obtaining Target States and Positions (getsta)
 
   To compute the apparent state of Mars as seen from TGO in the J2000
   frame, specify/select the following inputs in the ``State Vector''
   calculation:
 
      Target type               Object
      Target                    MARS
      Observer type             Object
      Observer                  EXOMARS 2016 TGO
      Reference frame           J2000
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      State representation      Rectangular
 
   WGC will return the following state vector, km and km/s:
 
      2911.82242547
      -2033.80245966
      -1291.70085522
      1.30950490
      -0.05597018
      3.10432898
 
   To compute the apparent position of Earth as seen from TGO in the J2000
   frame and one way light time between TGO and the apparent position of
   Earth, specify/select the following inputs in the ``State Vector''
   calculation:
 
      Target type               Object
      Target                    EARTH
      Observer type             Object
      Observer                  EXOMARS 2016 TGO
      Reference frame           J2000
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      State representation      Rectangular
 
   WGC will return the following position vector, km, and one way light
   time, s:
 
      -49609884.08045448
      57070665.86178913
      30304236.92973865
 
   To compute the apparent position of Sun as seen from Mars in the J2000
   frame, specify/select the following inputs in the ``State Vector''
   calculation:
 
      Target type               Object
      Target                    SUN
      Observer type             Object
      Observer                  MARS
      Reference frame           J2000
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      State representation      Rectangular
 
   WGC will return the following position vector, km:
 
      -24712734.28893231
      194560532.94319060
      89906636.78934350
 
   Note that WGC will also compute the distance between Sun and Mars body
   centers, km:
 
      215749214.49206870
 
   but it cannot convert this distance to AUs.
 
 
Obtaining Target States and Positions -- Selected Extra Credit
 
   4. To compute the position of the Sun as seen from Mars in the J2000
   using the following light time and aberration corrections: NONE, LT and
   LT+S, specify/select the following inputs in the ``State Vector''
   calculation (except for corrections):
 
      Target type               Object
      Target                    SUN
      Observer type             Object
      Observer                  MARS
      Reference frame           J2000
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      State representation      Rectangular
 
   and these corrections for NONE (the geometric position), LT (the
   reception light time only corrected position), and LT+S (the apparent
   position):
 
      Light propagation         No correction
 
      Light propagation         To observer
      Light-time algorithm      Newtonian
 
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
 
   WGC will return the following position vectors, km, correspondingly:
 
      -24730875.20069792
      194558449.55971023
      89906170.85450794
 
      -24730866.48857886
      194558445.24649155
      89906168.75352160
 
      -24712734.28893231
      194560532.94319060
      89906636.78934350
 
 
Spacecraft Orientation and Reference Frames (xform)
 
   To compute the apparent state of Mars as seen from TGO in the IAU_MARS
   body-fixed frame, specify/select the following inputs in the ``State
   Vector'' calculation:
 
      Target type               Object
      Target                    MARS
      Observer type             Object
      Observer                  EXOMARS 2016 TGO
      Reference frame           IAU_MARS
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      State representation      Rectangular
 
   WGC will return the following state vector, km and km/s:
 
      -2843.46412456
      2235.45954373
      1095.89496870
      0.31144328
      -1.15192925
      3.08212262
 
   To compute the angular separation between the apparent position of Mars
   and the TGO nominal instrument view direction, specify/select the
   following inputs in the ``Angular Separation'' calculation:
 
      Specification type        Two directions
      Direction type 1          Position
      Target 1                  MARS
      Target shape 1            Point
      Observer 1                EXOMARS 2016 TGO
      Light propagation 1       To observer
      Light-time algorithm 1    Newtonian
      Stellar aberration 1      Corrected for stellar aberration
      Use anti-vector 1         No
      Direction type 2          Vector
      Ray vector 2              Y axis in TGO_SPACECRAFT frame
      Correction type 2         None
      Use anti-vector 2         Yes
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
 
   WGC will return the following output separation angle, deg:
 
      5.43847143
 
 
Spacecraft Orientation and Reference Frames -- Selected Extra Credit
 
   2. To compute the angular separation between the apparent position of
   Sun and the TGO nominal instrument view direction to find out if the
   science deck illuminated, specify/select the following inputs in the
   ``Angular Separation'' calculation:
 
      Specification type        Two directions
      Direction type 1          Position
      Target 1                  SUN
      Target shape 1            Point
      Observer 1                EXOMARS 2016 TGO
      Light propagation 1       To observer
      Light-time algorithm 1    Newtonian
      Stellar aberration 1      Corrected for stellar aberration
      Use anti-vector 1         No
      Direction type 2          Vector
      Ray vector 2              Y axis in TGO_SPACECRAFT frame
      Correction type 2         None
      Use anti-vector 2         Yes
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
 
   WGC will return the following output separation angle, deg:
 
      130.54279733
 
   This angle is greater than 90 degrees so the science deck is not
   illuminated.
 
 
Computing Sub-s/c and Sub-solar Points on an Ellipsoid and a DSK (subpts)
 
   To compute the apparent sub-observer point of TGO on Mars in the
   IAU_MARS frame using the ``Near point: ellipsoid'' method,
   specify/select the following inputs in the ``Sub-Observer Point''
   calculation:
 
      Target                    MARS
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      2554.16465516
      -2008.01038262
      -983.24042077
 
   Note that WCG will compute the altitude but it will be labeled
   ``Observer Distance (km)'' in the output table and will have the
   following distance, km:
 
      385.04529279
 
   To compute the apparent sub-observer point of TGO on Mars in the
   IAU_MARS frame using a DSK shape model and the nadir point method,
   specify/select the following inputs in the ``Sub-Observer Point''
   calculation:
 
      Target                    MARS
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Sub-point type            NADIR/DSK/UNPRIORITIZED
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      2554.22331603
      -2008.05650034
      -983.26327153
 
   Note that WCG will compute the altitude but it will be labeled
   ``Observer Distance (km)'' in the output table and will have the
   following distance, km:
 
      384.96725758
 
   To compute the apparent sub-solar point on Mars as seen from TGO in the
   IAU_MARS frame using the ``Near point: ellipsoid'' method,
   specify/select the following inputs in the ``Sub-Solar Point''
   calculation:
 
      Target                    MARS
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      487.58869797
      -3348.61049793
      -286.69722014
 
   To compute the apparent sub-solar point on Mars as seen from TGO in the
   IAU_MARS frame using a DSK shape model and the nadir point method,
   specify/select the following inputs in the ``Sub-Solar Point''
   calculation:
 
      Target                    MARS
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Sub-point type            NADIR/DSK/UNPRIORITIZED
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      488.09583992
      -3352.09336966
      -286.99895399
 
 
Computing Sub-spacecraft and Sub-solar Points -- Selected Extra Credit
 
   1. To compute the apparent sub-solar point on Mars as seen from TGO in
   the IAU_MARS frame using the ``Intercept: ellipsoid'' method,
   specify/select the following inputs in the ``Sub-Solar Point''
   calculation:
 
      Target                    MARS
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Sub-point type            Intercept: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      487.54669671
      -3348.32205372
      -290.07721511
 
   2. To compute the apparent sub-observer point of TGO on Phobos in the
   IAU_PHOBOS frame using the 'Near point: ellipsoid' method,
   specify/select the following inputs in the ``Sub-Observer Point''
   calculation:
 
      Target                    PHOBOS
      Reference frame           IAU_PHOBOS
      Observer                  EXOMARS 2016 TGO
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      12.05913904
      4.17308831
      -0.67546616
 
   3. To compute the planetocentric coordinates of the apparent
   sub-observer point of TGO on Phobos in the IAU_PHOBOS frame using the
   'Near point: ellipsoid' method, specify/select the following inputs in
   the ``Sub-Observer Point'' calculation:
 
      Target                    PHOBOS
      Reference frame           IAU_PHOBOS
      Observer                  EXOMARS 2016 TGO
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Planetocentric
 
   WGC will return the following latitude and longitude, deg, and radius,
   km:
 
      -3.03000878
      19.08827715
      12.77864449
 
   WGC does not allow computing planetodetic and planetographic coordinates
   on bodies that are tri-axial ellipsoids with different equatorial radii.
   Choosing the planetographic coordinates for output will result in the
   following error message:
 
      Reference frame center is not a spheroid. Planetodetic and
      planetographic coordinate representations can only be
      calculated for bodies with equal equatorial axes. The center
      body of the reference frame, PHOBOS, has equatorial axes
      that differ, 13.0 and 11.4. Use planetocentric coordinates
      instead.
 
 
Intersecting Vectors with an Ellipsoid and a DSK (fovint)
 
   To compute the Cartesian position vectors of the FOV boundary vector
   surface intercept points on the surface of Mars modeled as an ellipsoid
   in the IAU_MARS frame, specify/select the following inputs in the
   ``Surface Intercept Point'' calculation:
 
      Target                    MARS
      Front body shape          Ellipsoid
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Ray vector                TGO_NOMAD_LNO_NAD
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vectors, km:
 
      2535.00445179
      -2028.52838809
      -990.59432639
 
      2525.05593461
      -2042.07461651
      -988.19646467
 
      2525.20138167
      -2042.10358036
      -987.76992477
 
      2535.14886773
      -2028.55774855
      -990.16957287
 
   To compute the planetocentric longitudes and latitudes of the FOV
   boundary vector surface intercept points on the surface of Mars modeled
   as an ellipsoid in the IAU_MARS frame, specify/select the following
   inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    MARS
      Front body shape          Ellipsoid
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Ray vector                TGO_NOMAD_LNO_NAD
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Planetocentric
 
   WGC will return the following longitudes and latitudes, deg:
 
      -38.66704048
      -16.96728341
 
      -38.96331703
      -16.92492977
 
      -38.96210076
      -16.91739679
 
      -38.66585276
      -16.95978024
 
   Both computations above also returned the illumination angles the FOV
   boundary vector surface intercept points but these angles were omitted
   from the output shown above.
 
   To compute the Cartesian position vectors of the FOV boresight surface
   intercept point on the surface of Mars modeled as an ellipsoid in the
   IAU_MARS frame, specify/select the following inputs in the ``Surface
   Intercept Point'' calculation:
 
      Target                    MARS
      Front body shape          Ellipsoid
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Ray vector                TGO_NOMAD_LNO_NAD boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      2530.12229730
      -2035.30663798
      -989.18816471
 
   To compute the planetocentric longitude and latitude of the FOV
   boresight surface intercept point on the surface of Mars modeled as an
   ellipsoid in the IAU_MARS frame and the illumination angles and the
   local solar time on a 24-hour clock at this point, specify/select the
   following inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    MARS
      Front body shape          Ellipsoid
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Ray vector                TGO_NOMAD_LNO_NAD boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      -38.81424755
      -16.94244506
 
   the following incidence, emission, and phase angles, deg:
 
      43.72871855
      6.08637448
      49.45727680
 
   and the following local solar time:
 
      14:51:36
 
   To compute the Cartesian position vectors of the FOV boundary vector
   surface intercept points on the surface of Mars in the IAU_MARS frame
   using a DSK shape model, specify/select the following inputs in the
   ``Surface Intercept Point'' calculation:
 
      Target                    MARS
      Front body shape          DSK model
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Ray vector                TGO_NOMAD_LNO_NAD
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vectors, km:
 
      2535.27825807
      -2028.71207603
      -990.68783903
 
      2525.35917194
      -2042.25880287
      -988.29907684
 
      2525.50638508
      -2042.28889640
      -987.87359025
 
      2535.42250373
      -2028.74138215
      -990.26344789
 
   To compute the planetocentric longitudes and latitudes of the FOV
   boundary vector surface intercept points on the surface of Mars in the
   IAU_MARS frame using a DSK shape model, specify/select the following
   inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    MARS
      Front body shape          DSK model
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Ray vector                TGO_NOMAD_LNO_NAD
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Planetocentric
 
   WGC will return the following longitudes and latitudes, deg:
 
      -38.66655257
      -16.96717476
 
      -38.96247962
      -16.92485905
 
      -38.96125942
      -16.91733365
 
      -38.66536612
      -16.95967901
 
   Both computations above also returned the illumination angles the FOV
   boundary vector surface intercept points but these angles were omitted
   from the output shown above.
 
   To compute the Cartesian position vectors of the FOV boresight surface
   intercept point on the surface of Mars in the IAU_MARS frame using a DSK
   shape model, specify/select the following inputs in the ``Surface
   Intercept Point'' calculation:
 
      Target                    MARS
      Front body shape          DSK model
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Ray vector                TGO_NOMAD_LNO_NAD boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      2530.47105768
      -2035.52942714
      -989.30698550
 
   To compute the planetocentric longitude and latitude of the FOV
   boresight surface intercept point on the surface of Mars in the IAU_MARS
   frame using a DSK shape model and the illumination angles and the local
   solar time on a 24-hour clock at this point, specify/select the
   following inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    MARS
      Front body shape          DSK model
      Reference frame           IAU_MARS
      Observer                  EXOMARS 2016 TGO
      Ray vector                TGO_NOMAD_LNO_NAD boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2018 JUN 11 19:32:00
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      -38.81345348
      -16.94234008
 
   the following incidence, emission, and phase angles, deg:
 
      44.38719437
      5.46181871
      49.45727689
 
   and the following local solar time:
 
      14:51:36
 
 
``KPLO Remote Sensing'' Hands-On Lesson Using WGC
--------------------------------------------------------
 
 
Kernels Used
 
   Use the ``SPICE Class - KPLO Remote Sensing Lesson Kernels'' kernel set
   appearing near the bottom of the ``Kernel selection:'' menu to do all
   steps in this lesson.
 
 
Time Conversion (convtm)
 
   To compute ET seconds past J2000, specify/select the following inputs in
   the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Output time system        TDB
      Output time format        Seconds past J2000
 
   WGC will return the following ET seconds past J2000:
 
      662822439.183960
 
   To compute calendar ET in the default format, specify/select the
   following inputs in the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Output time system        TDB
      Output time format        Calendar (year-month-day)
 
   WGC will return the following calendar ET time string:
 
      2021-01-02 01:20:39.183959 TDB
 
   To compute calendar ET in a custom format, specify/select the following
   inputs in the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Output time system        TDB
      Custom format             YYYY-MON-DDTHR:MN:SC ::TDB
 
   WGC will return the following calendar ET time string:
 
      2021-JAN-02T01:20:39
 
   To compute spacecraft clock time, specify/select the following inputs in
   the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Output time system        Spacecraft clock (SCLK=-155)
      Output time format        Spacecraft clock string
 
   WGC will return the following SCLK time string:
 
      1/1095:4530960
 
 
Time Conversion -- Selected Extra Credit
 
   1. To compute TDB Julian Date, specify/select the following inputs in
   the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Output time system        TDB
      Output time format        Julian Date
 
   WGC will return the following TDB time string:
 
      2459216.556009100 JD TDB
 
   5. To compute the earliest UTC time that can be converted to KPLO
   spacecraft clock, specify/select the following inputs in the ``Time
   Conversion'' calculation:
 
      Time system               Spacecraft clock (SCLK=-155)
      Time format               Spacecraft clock ticks
      Input time                0.0
      Output time system        UTC
      Output time format        Calendar (year-month-day)
 
   WGC will return the following UTC time string:
 
      2000-01-01 12:00:00.000000 UTC
 
   6. To convert the spacecraft clock time obtained in the regular task
   back to UTC Time and present it in ISO calendar date format, with a
   resolution of milliseconds, specify/select the following inputs in the
   ``Time Conversion'' calculation:
 
      Time system               Spacecraft clock (SCLK=-155)
      Time format               Spacecraft clock string
      Input time                1/1095:4530960
      Output time system        UTC
      Custom format             YYYY-MM-DDTHR:MN:SC.### ::RND
 
   WGC will return the following UTC time string:
 
      2021-01-02T01:19:30.000
 
 
Obtaining Target States and Positions (getsta)
 
   To compute the apparent state of Moon as seen from KPLO in the J2000
   frame, specify/select the following inputs in the ``State Vector''
   calculation:
 
      Target type               Object
      Target                    MOON
      Observer type             Object
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Reference frame           J2000
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      State representation      Rectangular
 
   WGC will return the following state vector, km and km/s:
 
      -1644.52619495
      403.44030666
      -659.48288212
      -0.68365295
      -0.53710111
      1.40358849
 
   To compute the apparent position of Earth as seen from KPLO in the J2000
   frame and one way light time between KPLO and the apparent position of
   Earth, specify/select the following inputs in the ``State Vector''
   calculation:
 
      Target type               Object
      Target                    EARTH
      Observer type             Object
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Reference frame           J2000
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      State representation      Rectangular
 
   WGC will return the following position vector, km, and one way light
   time, s:
 
      274796.47231277
      -229775.66219176
      -132406.96430545
 
   To compute the apparent position of Sun as seen from Moon in the J2000
   frame, specify/select the following inputs in the ``State Vector''
   calculation:
 
      Target type               Object
      Target                    SUN
      Observer type             Object
      Observer                  MOON
      Reference frame           J2000
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      State representation      Rectangular
 
   WGC will return the following position vector, km:
 
      29767887.20725118
      -132448141.93447962
      -57447546.63910401
 
   Note that WGC will also compute the distance between Sun and Moon body
   centers, km:
 
      147407116.60408977
 
   but it cannot convert this distance to AUs.
 
 
Obtaining Target States and Positions -- Selected Extra Credit
 
   4. To compute the position of the Sun as seen from Moon in the J2000
   using the following light time and aberration corrections: NONE, LT and
   LT+S, specify/select the following inputs in the ``State Vector''
   calculation (except for corrections):
 
      Target type               Object
      Target                    SUN
      Observer type             Object
      Observer                  MOON
      Reference frame           J2000
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      State representation      Rectangular
 
   and these corrections for NONE (the geometric position), LT (the
   reception light time only corrected position), and LT+S (the apparent
   position):
 
      Light propagation         No correction
 
      Light propagation         To observer
      Light-time algorithm      Newtonian
 
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
 
   WGC will return the following position vectors, km, correspondingly:
 
      29782863.55498986
      -132445301.95992541
      -57446341.26913592
 
      29782869.37259879
      -132445297.37780900
      -57446339.48277447
 
      29767887.20725118
      -132448141.93447962
      -57447546.63910401
 
 
Spacecraft Orientation and Reference Frames (xform)
 
   To compute the apparent state of Moon as seen from KPLO in the MOON_ME
   body-fixed frame, specify/select the following inputs in the ``State
   Vector'' calculation:
 
      Target type               Object
      Target                    MOON
      Observer type             Object
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Reference frame           MOON_ME
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      State representation      Rectangular
 
   WGC will return the following state vector, km and km/s:
 
      -1371.82545359
      -948.54151590
      -721.46522871
      -0.54249964
      -0.35188864
      1.51918815
 
   To compute the angular separation between the apparent position of Moon
   and the KPLO nominal instrument view direction, specify/select the
   following inputs in the ``Angular Separation'' calculation:
 
      Specification type        Two directions
      Direction type 1          Position
      Target 1                  MOON
      Target shape 1            Point
      Observer 1                KOREA PATHFINDER LUNAR ORBITER
      Light propagation 1       To observer
      Light-time algorithm 1    Newtonian
      Stellar aberration 1      Corrected for stellar aberration
      Use anti-vector 1         No
      Direction type 2          Vector
      Ray vector 2              Z axis in KPLO_SPACECRAFT frame
      Correction type 2         None
      Use anti-vector 2         No
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
 
   WGC will return the following output separation angle, deg:
 
      29.98967834
 
 
Spacecraft Orientation and Reference Frames -- Selected Extra Credit
 
   2. To compute the angular separation between the apparent position of
   Sun and the KPLO nominal instrument view direction to find out if the
   science deck illuminated, specify/select the following inputs in the
   ``Angular Separation'' calculation:
 
      Specification type        Two directions
      Direction type 1          Position
      Target 1                  SUN
      Target shape 1            Point
      Observer 1                KOREA PATHFINDER LUNAR ORBITER
      Light propagation 1       To observer
      Light-time algorithm 1    Newtonian
      Stellar aberration 1      Corrected for stellar aberration
      Use anti-vector 1         No
      Direction type 2          Vector
      Ray vector 2              Z axis in KPLO_SPACECRAFT frame
      Correction type 2         None
      Use anti-vector 2         No
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
 
   WGC will return the following output separation angle, deg:
 
      133.58682151
 
   This angle is greater than 90 degrees so the science deck is not
   illuminated.
 
 
Computing Sub-s/c and Sub-solar Points on an Ellipsoid and a DSK (subpts)
 
   To compute the apparent sub-observer point of KPLO on Moon in the
   MOON_ME frame using the ``Near point: ellipsoid'' method, specify/select
   the following inputs in the ``Sub-Observer Point'' calculation:
 
      Target                    MOON
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1311.59999155
      906.89881368
      689.78167845
 
   Note that WCG will compute the altitude but it will be labeled
   ``Observer Distance (km)'' in the output table and will have the
   following distance, km:
 
      79.93809991
 
   To compute the apparent sub-observer point of KPLO on Moon in the
   MOON_ME frame using a DSK shape model and the nadir point method,
   specify/select the following inputs in the ``Sub-Observer Point''
   calculation:
 
      Target                    MOON
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Sub-point type            NADIR/DSK/UNPRIORITIZED
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1310.56131465
      906.18062554
      689.23543792
 
   Note that WCG will compute the altitude but it will be labeled
   ``Observer Distance (km)'' in the output table and will have the
   following distance, km:
 
      81.31384578
 
   To compute the apparent sub-solar point on Moon as seen from KPLO in the
   MOON_ME frame using the ``Near point: ellipsoid'' method, specify/select
   the following inputs in the ``Sub-Solar Point'' calculation:
 
      Target                    MOON
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1333.60421904
      -1113.43170986
      -18.12110449
 
   To compute the apparent sub-solar point on Moon as seen from KPLO in the
   MOON_ME frame using a DSK shape model and the nadir point method,
   specify/select the following inputs in the ``Sub-Solar Point''
   calculation:
 
      Target                    MOON
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Sub-point type            NADIR/DSK/UNPRIORITIZED
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1332.31355108
      -1112.35412588
      -18.10356680
 
 
Computing Sub-spacecraft and Sub-solar Points -- Selected Extra Credit
 
   1. To compute the apparent sub-solar point on Moon as seen from KPLO in
   the MOON_ME frame using the ``Intercept: ellipsoid'' method,
   specify/select the following inputs in the ``Sub-Solar Point''
   calculation:
 
      Target                    MOON
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Sub-point type            Intercept: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1333.60421904
      -1113.43170986
      -18.12110449
 
   2. To compute the geometric sub-observer point of KPLO on Mars in the
   IAU_MARS frame using the 'Near point: ellipsoid' method, specify/select
   the following inputs in the ``Sub-Observer Point'' calculation:
 
      Target                    MARS
      Reference frame           IAU_MARS
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Sub-point type            Near point: ellipsoid
      Light propagation         No correction
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      -3128.42290664
      -249.60832325
      -1290.34782992
 
   3. To compute the planetocentric coordinates of the apparent
   sub-observer point of KPLO on Mars in the IAU_MARS frame using the 'Near
   point: ellipsoid' method, specify/select the following inputs in the
   ``Sub-Observer Point'' calculation:
 
      Target                    MARS
      Reference frame           IAU_MARS
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Planetocentric
 
   WGC will return the following planetocentric longitude and latitude,
   deg, and radius, km:
 
      -173.59883389
      -22.35046430
      3393.27735444
 
   To compute the planetographic coordinates of the apparent sub-observer
   point of KPLO on Mars in the IAU_MARS frame using the 'Near point:
   ellipsoid' method, specify/select the following inputs in the
   ``Sub-Observer Point'' calculation:
 
      Target                    MARS
      Reference frame           IAU_MARS
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Planetographic
 
   WGC will return the following planetographic longitude and latitude,
   deg, and radius, km:
 
      173.59883389
      -22.58938265
      3393.27735444
 
 
Intersecting Vectors with an Ellipsoid and a DSK (fovint)
 
   To compute the Cartesian position vectors of the FOV boundary vector
   surface intercept points on the surface of Moon modeled as an ellipsoid
   in the MOON_ME frame, specify/select the following inputs in the
   ``Surface Intercept Point'' calculation:
 
      Target                    MOON
      Front body shape          Ellipsoid
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Ray vector                KPLO_POLCAM-R
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Rectangular
 
   WGC will return the following position vectors, km:
 
      1330.39103977
      884.38754332
      682.99129900
 
      1325.50103256
      881.18320405
      696.50695157
 
      1317.31188523
      893.66760811
      696.13674177
 
      1321.96554453
      896.72462104
      683.26481915
 
   To compute the planetocentric longitudes and latitudes of the FOV
   boundary vector surface intercept points on the surface of Moon modeled
   as an ellipsoid in the MOON_ME frame, specify/select the following
   inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    MOON
      Front body shape          Ellipsoid
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Ray vector                KPLO_POLCAM-R
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Planetocentric
 
   WGC will return the following longitudes and latitudes, deg:
 
      33.61427482
      23.14822282
 
      33.61566370
      23.63385243
 
      34.15306470
      23.62052663
 
      34.15009526
      23.15803308
 
   Both computations above also returned the illumination angles the FOV
   boundary vector surface intercept points but these angles were omitted
   from the output shown above.
 
   To compute the Cartesian position vectors of the FOV boresight surface
   intercept point on the surface of Moon modeled as an ellipsoid in the
   MOON_ME frame, specify/select the following inputs in the ``Surface
   Intercept Point'' calculation:
 
      Target                    MOON
      Front body shape          Ellipsoid
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Ray vector                KPLO_POLCAM-R boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1323.70921165
      889.16480649
      689.73808789
 
   To compute the planetocentric longitude and latitude of the FOV
   boresight surface intercept point on the surface of Moon modeled as an
   ellipsoid in the MOON_ME frame and the illumination angles and the local
   solar time on a 24-hour clock at this point, specify/select the
   following inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    MOON
      Front body shape          Ellipsoid
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Ray vector                KPLO_POLCAM-R boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      33.89013253
      23.39041849
 
   the following incidence, emission, and phase angles, deg:
 
      75.36348395
      15.71930997
      90.97449383
 
   and the following local solar time:
 
      16:54:59
 
   To compute the Cartesian position vectors of the FOV boundary vector
   surface intercept points on the surface of Moon in the MOON_ME frame
   using a DSK shape model, specify/select the following inputs in the
   ``Surface Intercept Point'' calculation:
 
      Target                    MOON
      Front body shape          DSK model
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Ray vector                KPLO_POLCAM-R
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Rectangular
 
   WGC will return the following position vectors, km:
 
      1330.03476491
      883.83684875
      682.66101343
 
      1324.62670338
      879.91370704
      696.03612460
 
      1315.94194737
      892.28962201
      695.50031146
 
      1321.20632985
      895.93628065
      682.68377376
 
   To compute the planetocentric longitudes and latitudes of the FOV
   boundary vector surface intercept points on the surface of Moon in the
   MOON_ME frame using a DSK shape model, specify/select the following
   inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    MOON
      Front body shape          DSK model
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Ray vector                KPLO_POLCAM-R
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Planetocentric
 
   WGC will return the following longitudes and latitudes, deg:
 
      33.60489695
      23.14600512
 
      33.59501327
      23.63854822
 
      34.13968615
      23.62650516
 
      34.14197605
      23.15430060
 
   Both computations above also returned the illumination angles the FOV
   boundary vector surface intercept points but these angles were omitted
   from the output shown above.
 
   To compute the Cartesian position vectors of the FOV boresight surface
   intercept point on the surface of Moon in the MOON_ME frame using a DSK
   shape model, specify/select the following inputs in the ``Surface
   Intercept Point'' calculation:
 
      Target                    MOON
      Front body shape          DSK model
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Ray vector                KPLO_POLCAM-R boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1322.78357023
      888.02386624
      689.12826986
 
   To compute the planetocentric longitude and latitude of the FOV
   boresight surface intercept point on the surface of Moon in the MOON_ME
   frame using a DSK shape model and the illumination angles and the local
   solar time on a 24-hour clock at this point, specify/select the
   following inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    MOON
      Front body shape          DSK model
      Reference frame           MOON_ME
      Observer                  KOREA PATHFINDER LUNAR ORBITER
      Ray vector                KPLO_POLCAM-R boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2021 JAN 02 01:19:30
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      33.87463406
      23.39034854
 
   the following incidence, emission, and phase angles, deg:
 
      79.62243678
      12.44723587
      90.97449322
 
   and the following local solar time:
 
      16:54:55
 
 
``BepiColombo MPO Remote Sensing'' Hands-On Lesson Using WGC
--------------------------------------------------------
 
 
Kernels Used
 
   Use the ``SPICE Class - BepiColombo MPO Remote Sensing Lesson Kernels''
   kernel set appearing near the bottom of the ``Kernel selection:'' menu
   to do all steps in this lesson.
 
 
Time Conversion (convtm)
 
   To compute ET seconds past J2000, specify/select the following inputs in
   the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Output time system        TDB
      Output time format        Seconds past J2000
 
   WGC will return the following ET seconds past J2000:
 
      852386745.184030
 
   To compute calendar ET in the default format, specify/select the
   following inputs in the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Output time system        TDB
      Output time format        Calendar (year-month-day)
 
   WGC will return the following calendar ET time string:
 
      2027-01-05 02:05:45.184031 TDB
 
   To compute calendar ET in a custom format, specify/select the following
   inputs in the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Output time system        TDB
      Custom format             YYYY-MON-DDTHR:MN:SC ::TDB
 
   WGC will return the following calendar ET time string:
 
      2027-JAN-05T02:05:45
 
   To compute spacecraft clock time, specify/select the following inputs in
   the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Output time system        Spacecraft clock (SCLK=-121)
      Output time format        Spacecraft clock string
 
   WGC will return the following SCLK time string:
 
      1/0863834674:28127
 
 
Time Conversion -- Selected Extra Credit
 
   1. To compute TDB Julian Date, specify/select the following inputs in
   the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Output time system        TDB
      Output time format        Julian Date
 
   WGC will return the following TDB time string:
 
      2461410.5873285187 JD TDB
 
   5. To compute the earliest UTC time that can be converted to BepiColombo
   MPO spacecraft clock, specify/select the following inputs in the ``Time
   Conversion'' calculation:
 
      Time system               Spacecraft clock (SCLK=-121)
      Time format               Spacecraft clock ticks
      Input time                0.0
      Output time system        UTC
      Output time format        Calendar (year-month-day)
 
   WGC will return the following UTC time string:
 
      1999-08-22 00:00:05.204000 UTC
 
   6. To convert the spacecraft clock time obtained in the regular task
   back to UTC Time and present it in ISO calendar date format, with a
   resolution of milliseconds, specify/select the following inputs in the
   ``Time Conversion'' calculation:
 
      Time system               Spacecraft clock (SCLK=-121)
      Time format               Spacecraft clock string
      Input time                1/0863834674:28127
      Output time system        UTC
      Custom format             YYYY-MM-DDTHR:MN:SC.### ::RND
 
   WGC will return the following UTC time string:
 
      2027-01-05T02:04:36.000
 
 
Obtaining Target States and Positions (getsta)
 
   To compute the apparent state of MERCURY as seen from MPO in the J2000
   frame, specify/select the following inputs in the ``State Vector''
   calculation:
 
      Target type               Object
      Target                    MERCURY
      Observer type             Object
      Observer                  BEPICOLOMBO MPO
      Reference frame           J2000
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      State representation      Rectangular
 
   WGC will return the following state vector, km and km/s:
 
      -683.20708781
      -1438.94585601
      -2427.81935629
      0.03613279
      2.35990408
      -1.78341780
 
   To compute the apparent position of Earth as seen from MPO in the J2000
   frame and one way light time between MPO and the apparent position of
   Earth, specify/select the following inputs in the ``State Vector''
   calculation:
 
      Target type               Object
      Target                    EARTH
      Observer type             Object
      Observer                  BEPICOLOMBO MPO
      Reference frame           J2000
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      State representation      Rectangular
 
   WGC will return the following position vector, km, and one way light
   time, s:
 
      -59257854.69091041
      185201786.21846142
      88178321.17891033
 
      712.19341196
 
   To compute the apparent position of Sun as seen from Mercury in the
   J2000 frame, specify/select the following inputs in the ``State Vector''
   calculation:
 
      Target type               Object
      Target                    SUN
      Observer type             Object
      Observer                  MERCURY
      Reference frame           J2000
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      State representation      Rectangular
 
   WGC will return the following position vector, km:
 
      -23429947.23907467
      54297427.57199317
      31434173.46824882
 
   Note that WGC will also compute the distance between Sun and MERCURY
   body centers, km:
 
      66972235.51736662
 
   but it cannot convert this distance to AUs.
 
 
Obtaining Target States and Positions -- Selected Extra Credit
 
   2. To compute the geometric position of Jupiter as seen from Mercury in
   the J2000 frame, manually load a JUP365 Jovian satellite ephemeris SPK
   from the generic kernels area and specify/select the following inputs in
   the ``State Vector'' calculation:
 
      Target type               Object
      Target                    JUPITER
      Observer type             Object
      Observer                  MERCURY
      Reference frame           J2000
      Light propagation         No correction
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      State representation      Rectangular
 
   WGC will return the following position vector, km:
 
      -623644094.41838810
      532767093.11246020
      251130102.03451324
 
   3. To compute the position of the Sun as seen from Mercury in the J2000
   frame using the following light time and aberration corrections: NONE,
   LT and LT+S, with the JUP365 Jovian satellite ephemeris SPK still
   loaded, specify/select the following inputs in the ``State Vector''
   calculation (except for corrections):
 
      Target type               Object
      Target                    SUN
      Observer type             Object
      Observer                  MERCURY
      Reference frame           J2000
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      State representation      Rectangular
 
   and these corrections for NONE (the geometric position), LT (the
   reception light time only corrected position), and LT+S (the apparent
   position):
 
      Light propagation         No correction
 
      Light propagation         To observer
      Light-time algorithm      Newtonian
 
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
 
   WGC will return the following position vectors, km, correspondingly:
 
      -23438490.40236970
      54294213.48461554
      31433347.02463599
 
      -23438492.54961504
      54294212.27207869
      31433346.55007268
 
      -23430052.90345647
      54297381.15594409
      31434164.77541952
 
   Unload the JUP365 Jovian satellite ephemeris SPK before proceeding to
   the next step.
 
 
Spacecraft Orientation and Reference Frames (xform)
 
   To compute the apparent state of MERCURY as seen from MPO in the
   IAU_MERCURY body-fixed frame, specify/select the following inputs in the
   ``State Vector'' calculation:
 
      Target type               Object
      Target                    MERCURY
      Observer type             Object
      Observer                  BEPICOLOMBO MPO
      Reference frame           IAU_MERCURY
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      State representation      Rectangular
 
   WGC will return the following state vector, km and km/s:
 
      -2354.69762022
      -762.54754931
      -1518.40846958
      1.20858923
      0.39425920
      -2.67112542
 
   To compute the angular separation between the apparent position of
   MERCURY and the MPO nominal instrument view direction, specify/select
   the following inputs in the ``Angular Separation'' calculation:
 
      Specification type        Two directions
      Direction type 1          Position
      Target 1                  MERCURY
      Target shape 1            Point
      Observer 1                BEPICOLOMBO MPO
      Light propagation 1       To observer
      Light-time algorithm 1    Newtonian
      Stellar aberration 1      Corrected for stellar aberration
      Use anti-vector 1         No
      Direction type 2          Vector
      Ray vector 2              Z axis in MPO_SPACECRAFT frame
      Correction type 2         None
      Use anti-vector 2         No
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
 
   WGC will return the following output separation angle, deg:
 
      0.00897766
 
 
Spacecraft Orientation and Reference Frames -- Selected Extra Credit
 
   2. To compute the angular separation between the apparent position of
   Sun and the MPO nominal instrument view direction to find out if the
   science deck illuminated, specify/select the following inputs in the
   ``Angular Separation'' calculation:
 
      Specification type        Two directions
      Direction type 1          Position
      Target 1                  SUN
      Target shape 1            Point
      Observer 1                BEPICOLOMBO MPO
      Light propagation 1       To observer
      Light-time algorithm 1    Newtonian
      Stellar aberration 1      Corrected for stellar aberration
      Use anti-vector 1         No
      Direction type 2          Vector
      Ray vector 2              Z axis in MPO_SPACECRAFT frame
      Correction type 2         None
      Use anti-vector 2         No
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
 
   WGC will return the following output separation angle, deg:
 
      135.39275877
 
   This angle is greater than 90 degrees so the science deck is not
   illuminated.
 
 
Computing Sub-s/c and Sub-solar Points on an Ellipsoid and a DSK (subpts)
 
   To compute the apparent sub-observer point of MPO on MERCURY in the
   IAU_MERCURY frame using the ``Near point: ellipsoid'' method,
   specify/select the following inputs in the ``Sub-Observer Point''
   calculation:
 
      Target                    MERCURY
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1978.72631908
      640.79260145
      1275.61063011
 
   Note that WCG will compute the altitude but it will be labeled
   ``Observer Distance (km)'' in the output table and will have the
   following distance, km:
 
      463.63403747
 
   To compute the apparent sub-observer point of MPO on MERCURY in the
   IAU_MERCURY frame using a DSK shape model and the nadir point method,
   specify/select the following inputs in the ``Sub-Observer Point''
   calculation:
 
      Target                    MERCURY
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Sub-point type            NADIR/DSK/UNPRIORITIZED
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1979.55761722
      641.06180756
      1276.14754350
 
   Note that WCG will compute the altitude but it will be labeled
   ``Observer Distance (km)'' in the output table and will have the
   following distance, km:
 
      462.60838580
 
   To compute the apparent sub-solar point on MERCURY as seen from MPO in
   the IAU_MERCURY frame using the ``Near point: ellipsoid'' method,
   specify/select the following inputs in the ``Sub-Solar Point''
   calculation:
 
      Target                    MERCURY
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1526.83084694
      1903.93597088
      -1.43551256
 
   To compute the apparent sub-solar point on MERCURY as seen from MPO in
   the IAU_MERCURY frame using a DSK shape model and the nadir point
   method, specify/select the following inputs in the ``Sub-Solar Point''
   calculation:
 
      Target                    MERCURY
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Sub-point type            NADIR/DSK/UNPRIORITIZED
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1525.67256731
      1902.49161289
      -1.43442153
 
 
Computing Sub-spacecraft and Sub-solar Points -- Selected Extra Credit
 
   1. To compute the apparent sub-solar point on MERCURY as seen from MPO
   in the IAU_MERCURY frame using the ``Intercept: ellipsoid'' method,
   manually load a JUP365 Jovian satellite ephemeris SPK that will be
   needed for subsequent ``Extra Credit steps'' from the generic kernels
   area and specify/select the following inputs in the ``Sub-Solar Point''
   calculation:
 
      Target                    MERCURY
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Sub-point type            Intercept: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1526.82756104
      1903.93860405
      -1.43802202
 
   2. To compute the geometric sub-observer point of MPO on Europa in the
   IAU_EUROPA frame using the 'Near point: ellipsoid' method,
   specify/select the following inputs in the ``Sub-Observer Point''
   calculation:
 
      Target                    EUROPA
      Reference frame           IAU_EUROPA
      Observer                  BEPICOLOMBO MPO
      Sub-point type            Near point: ellipsoid
      Light propagation         No correction
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      -753.48359857
      -1366.70324298
      -24.29565536
 
   3. To compute the planetocentric coordinates of the apparent
   sub-observer point of MPO on Europa in the IAU_EUROPA frame using the
   'Near point: ellipsoid' method, specify/select the following inputs in
   the ``Sub-Observer Point'' calculation:
 
      Target                    EUROPA
      Reference frame           IAU_EUROPA
      Observer                  BEPICOLOMBO MPO
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Planetocentric
 
   WGC will return the following latitude and longitude, deg, and radius,
   km:
 
      -0.89189109
      -118.86859441
      1560.83489408
 
   WGC does not allow computing planetodetic and planetographic coordinates
   on bodies that are tri-axial ellipsoids with different equatorial radii.
   Choosing the planetographic coordinates for output will result in the
   following error message:
 
      Reference frame center is not a spheroid. Planetodetic and
      planetographic coordinate representations can only be
      calculated for bodies with equal equatorial axes. The center
      body of the reference frame, EUROPA, has equatorial axes
      that differ, 1562.6 and 1560.3. Use planetocentric coordinates
      instead.
 
   Unload the JUP365 Jovian satellite ephemeris SPK before proceeding to
   the next step.
 
 
Intersecting Vectors with an Ellipsoid and a DSK (fovint)
 
   To compute the Cartesian position vectors of the FOV boundary vector
   surface intercept points on the surface of MERCURY modeled as an
   ellipsoid in the IAU_MERCURY frame, specify/select the following inputs
   in the ``Surface Intercept Point'' calculation:
 
      Target                    MERCURY
      Front body shape          Ellipsoid
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Ray vector                MPO_SIMBIO-SYS_HRIC_FPA
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Rectangular
 
   WGC will return the following position vectors, km:
 
      1973.71676409
      645.43602637
      1281.00907254
 
      1979.64324274
      647.35380261
      1270.87514457
 
      1983.30742254
      636.03711992
      1270.87623002
 
      1977.38104498
      634.11904820
      1281.01014962
 
   To compute the planetocentric longitudes and latitudes of the FOV
   boundary vector surface intercept points on the surface of MERCURY
   modeled as an ellipsoid in the IAU_MERCURY frame, specify/select the
   following inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    MERCURY
      Front body shape          Ellipsoid
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Ray vector                MPO_SIMBIO-SYS_HRIC_FPA
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Planetocentric
 
   WGC will return the following longitudes and latitudes, deg:
 
      18.10854840
      31.66988939
 
      18.10801829
      31.39055578
 
      17.78079510
      31.39058566
 
      17.78033503
      31.66991913
 
   Both computations above also returned the illumination angles the FOV
   boundary vector surface intercept points but these angles were omitted
   from the output shown above.
 
   To compute the Cartesian position vectors of the FOV boresight surface
   intercept point on the surface of MERCURY modeled as an ellipsoid in the
   IAU_MERCURY frame, specify/select the following inputs in the ``Surface
   Intercept Point'' calculation:
 
      Target                    MERCURY
      Front body shape          Ellipsoid
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Ray vector                MPO_SIMBIO-SYS_HRIC_FPA boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1978.52391704
      640.74031886
      1275.95016484
 
   To compute the planetocentric longitude and latitude of the FOV
   boresight surface intercept point on the surface of MERCURY modeled as
   an ellipsoid in the IAU_MERCURY frame and the illumination angles and
   the local solar time on a 24-hour clock at this point, specify/select
   the following inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    MERCURY
      Front body shape          Ellipsoid
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Ray vector                MPO_SIMBIO-SYS_HRIC_FPA boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      17.94442417
      31.53033979
 
   the following incidence, emission, and phase angles, deg:
 
      44.64363856
      0.05864845
      44.60856489
 
   and the following local solar time:
 
      09:46:41
 
   To compute the Cartesian position vectors of the FOV boundary vector
   surface intercept points on the surface of MERCURY in the IAU_MERCURY
   frame using a DSK shape model, specify/select the following inputs in
   the ``Surface Intercept Point'' calculation:
 
      Target                    MERCURY
      Front body shape          DSK model
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Ray vector                MPO_SIMBIO-SYS_HRIC_FPA
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Rectangular
 
   WGC will return the following position vectors, km:
 
      1974.25716440
      645.60214021
      1281.34585342
 
      1980.44938049
      647.60139206
      1271.40726839
 
      1984.03435100
      636.28474958
      1271.36080444
 
      1978.15849786
      634.38367993
      1281.49936711
 
   To compute the planetocentric longitudes and latitudes of the FOV
   boundary vector surface intercept points on the surface of MERCURY in
   the IAU_MERCURY frame using a DSK shape model, specify/select the
   following inputs in the ``Surface Intercept Point'' calculation:
 
      Target                    MERCURY
      Front body shape          DSK model
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Ray vector                MPO_SIMBIO-SYS_HRIC_FPA
                                field-of-view boundary vectors
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Planetocentric
 
   WGC will return the following longitudes and latitudes, deg:
 
      18.10827034
      31.66965115
 
      18.10759955
      31.39090934
 
      17.78117498
      31.39090758
 
      17.78073720
      31.66957299
 
   Both computations above also returned the illumination angles the FOV
   boundary vector surface intercept points but these angles were omitted
   from the output shown above.
 
   To compute the Cartesian position vectors of the FOV boresight surface
   intercept point on the surface of MERCURY in the IAU_MERCURY frame using
   a DSK shape model, specify/select the following inputs in the ``Surface
   Intercept Point'' calculation:
 
      Target                    MERCURY
      Front body shape          DSK model
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Ray vector                MPO_SIMBIO-SYS_HRIC_FPA boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Rectangular
 
   WGC will return the following position vector, km:
 
      1979.35742495
      641.01021051
      1276.48746436
 
   To compute the planetocentric longitude and latitude of the FOV
   boresight surface intercept point on the surface of MERCURY in the
   IAU_MERCURY frame using a DSK shape model and the illumination angles
   and the local solar time on a 24-hour clock at this point,
   specify/select the following inputs in the ``Surface Intercept Point''
   calculation:
 
      Target                    MERCURY
      Front body shape          DSK model
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Ray vector                MPO_SIMBIO-SYS_HRIC_FPA boresight
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      17.94442318
      31.53033533
 
   the following incidence, emission, and phase angles, deg:
 
      45.34859624
      1.13773104
      44.60856527
 
   and the following local solar time:
 
      09:46:41
 
 
``CASSINI In-situ Sensing'' Hands-On Lesson Using WGC
--------------------------------------------------------
 
 
Kernels Used
 
   Use the ``SPICE Class - CASSINI In-situ Sensing Lesson Kernels'' kernel
   set appearing near the bottom of the ``Kernel selection:'' menu to do
   all steps in this lesson.
 
 
Step-1: ``UTC to ET''
 
   To compute ET seconds past J2000 for a given UTC string, specify/select
   the following inputs in the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2004-06-11T19:32:00
      Output time system        TDB
      Output time format        Seconds past J2000
 
   WGC will return the following ET seconds past J2000:
 
      140254384.184620
 
 
Step-2: ``SCLK to ET''
 
   To compute ET seconds past J2000 for a given SCLK string, specify/select
   the following inputs in the ``Time Conversion'' calculation:
 
      Time system               Spacecraft clock (SCLK=-82)
      Time format               Spacecraft clock string
      Input time                1465674964.105
      Output time system        TDB
      Output time format        Seconds past J2000
 
   WGC will return the following ET seconds past J2000:
 
      140254384.183430
 
   Either the input SCLK time or these output ET seconds past J2000 should
   be used as the input time in all remaining ``In-situ Sensing'' lesson
   steps in order for WGC to compute values matching the results provided
   in the programming lesson. The output ET seconds may be saved for future
   use in the WGC ``Saved Values'' area by simply clicking on them with the
   left mouse button. The saved value can then be drag-n-dropped from the
   ``Saved Values'' area into the empty ``Time:'' box in the next
   calculation.
 
 
Step-3: ``Spacecraft State''
 
   To compute the geometric state of the CASSINI spacecraft with respect to
   the Sun in the Ecliptic frame, specify/select the following inputs in
   the ``State Vector'' calculation:
 
      Target type               Object
      Target                    CASSINI
      Observer type             Object
      Observer                  SUN
      Reference frame           ECLIPJ2000
      Light propagation         No correction
      Time system               TDB
      Time format               Seconds past J2000
      Input time                140254384.183430
      State representation      Rectangular
 
   WGC will return the following state vector, km and km/s:
 
      -376599061.91656125
      1294487780.92915730
      -7064853.05469811
      -5.16422619
      0.80171891
      0.04060306
 
 
Step-4: ``Sun Direction''
 
   To compute the apparent direction of the Sun in the INMS frame,
   specify/select the following inputs in the ``Pointing Direction''
   calculation:
 
      Calculation type          Pointing Direction
      Direction type            Position
      Target                    SUN
      Observer                  CASSINI
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Use anti-vector           No
      Time system               TDB
      Time format               Seconds past J2000
      Input time                140254384.183430
      Reference frame           CASSINI_INMS
      Vector magnitude          Unit
      Coordinate system         Rectangular
 
   WGC will return the following unit vector along the Sun direction:
 
      -0.29020402
      0.88163119
      0.37216672
 
 
Step-5: ``Sub-Spacecraft Point''
 
   To compute the planetocentric longitude and latitude of the CASSINI
   sub-spacecraft point on Phoebe, specify/select the following inputs in
   the ``Sub-Observer Point'' calculation:
 
      Target                    PHOEBE
      Reference frame           IAU_PHOEBE
      Observer                  CASSINI
      Sub-point type            Near point: ellipsoid
      Light propagation         No correction
      Time system               TDB
      Time format               Seconds past J2000
      Input time                140254384.183430
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      23.42315899
      3.70979740
 
   WGC cannot compute the direction from the CASSINI spacecraft to the
   sub-spacecraft point in the INMS frame.
 
 
Step-6: ``Spacecraft Velocity''
 
   To compute the CASSINI spacecraft velocity with respect to Phoebe in the
   INMS frame, specify/select the following inputs in the ``Pointing
   Direction'' calculation:
 
      Calculation type          Pointing Direction
      Direction type            Velocity
      Target                    CASSINI
      Observer                  Phoebe
      Reference frame           J2000
      Light propagation         No correction
      Use anti-vector           No
      Time system               TDB
      Time format               Seconds past J2000
      Input time                140254384.183430
      Reference frame           CASSINI_INMS
      Vector magnitude          Unit
      Coordinate system         Rectangular
 
   WGC will return the following unit vector along the velocity direction:
 
      0.39578487
      -0.29280766
      0.87041255
 
 
``BepiColombo MPO In-situ Sensing'' Hands-On Lesson Using WGC
--------------------------------------------------------
 
 
Kernels Used
 
   Use the ``SPICE Class - BepiColombo MPO In-situ Sensing Lesson Kernels''
   kernel set appearing near the bottom of the ``Kernel selection:'' menu
   to do all steps in this lesson.
 
 
Step-1: ``UTC to ET''
 
   To compute ET seconds past J2000 for a given UTC string, specify/select
   the following inputs in the ``Time Conversion'' calculation:
 
      Time system               UTC
      Time format               Calendar date and time
      Input time                2027 JAN 05 02:04:36
      Output time system        TDB
      Output time format        Seconds past J2000
 
   WGC will return the following ET seconds past J2000:
 
      852386745.184030
 
 
Step-2: ``SCLK to ET''
 
   To compute ET seconds past J2000 for a given SCLK string, specify/select
   the following inputs in the ``Time Conversion'' calculation:
 
      Time system               Spacecraft clock (SCLK=-121)
      Time format               Spacecraft clock string
      Input time                863834674:28127
      Output time system        TDB
      Output time format        Seconds past J2000
 
   WGC will return the following ET seconds past J2000:
 
      852386745.184040
 
   The input SCLK time should be used as the input time in all remaining
   ``In-situ Sensing'' lesson steps in order for WGC to compute values
   matching the results provided in the programming lesson. The input SCLK
   time may be saved for future use in the WGC ``Saved Values'' area by
   simply clicking on it in the results table with the left mouse button.
   The saved value can then be drag-n-dropped from the ``Saved Values''
   area into the empty ``Time:'' box in the next calculation.
 
 
Step-3: ``Spacecraft State''
 
   To compute the geometric state of the BepiColombo MPO spacecraft with
   respect to the Sun in the Ecliptic frame, specify/select the following
   inputs in the ``State Vector'' calculation:
 
      Target type               Object
      Target                    BEPICOLOMBO MPO
      Observer type             Object
      Observer                  SUN
      Reference frame           ECLIPJ2000
      Light propagation         No correction
      Time system               Spacecraft clock (SCLK=-121)
      Time format               Spacecraft clock string
      Input time                863834674:28127
      State representation      Rectangular
 
   WGC will return the following state vector, km and km/s:
 
      23439067.89610513
      -62315194.63894688
      -7240868.73859754
      35.79932269
      18.15198781
      0.89057038
 
 
Step-4: ``Sun Direction''
 
   To compute the apparent direction of the Sun in the SERENA STROFIO +X
   Buffle frame, specify/select the following inputs in the ``Pointing
   Direction'' calculation:
 
      Calculation type          Pointing Direction
      Direction type            Position
      Target                    SUN
      Observer                  BEPICOLOMBO MPO
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Use anti-vector           No
      Time system               Spacecraft clock (SCLK=-121)
      Time format               Spacecraft clock string
      Input time                863834674:28127
      Reference frame           MPO_SERENA_STROFIO+X
      Vector magnitude          Unit
      Coordinate system         Rectangular
 
   WGC will return the following unit vector along the Sun direction:
 
      0.71193730
      0.54950539
      -0.43725177
 
 
Step-5: ``Sub-Spacecraft Point''
 
   To compute the planetocentric longitude and latitude of the BEPICOLOMBO
   MPO sub-spacecraft point on Mercury, specify/select the following inputs
   in the ``Sub-Observer Point'' calculation:
 
      Target                    MERCURY
      Reference frame           IAU_MERCURY
      Observer                  BEPICOLOMBO MPO
      Sub-point type            Near point: ellipsoid
      Light propagation         No correction
      Time system               Spacecraft clock (SCLK=-121)
      Time format               Spacecraft clock string
      Input time                863834674:28127
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      17.94407694
      31.52107152
 
   WGC cannot compute the direction from the BepiColombo MPO spacecraft to
   the sub-spacecraft point in the SERENA STROFIO +X Buffle frame.
 
 
Step-6: ``Spacecraft Velocity''
 
   To compute the BepiColombo MPO spacecraft velocity with respect to
   Mercury in the SERENA STROFIO +X Buffle frame, specify/select the
   following inputs in the ``Pointing Direction'' calculation:
 
      Calculation type          Pointing Direction
      Direction type            Velocity
      Target                    BEPICOLOMBO MPO
      Observer                  MERCURY
      Reference frame           J2000
      Light propagation         No correction
      Use anti-vector           No
      Time system               Spacecraft clock (SCLK=-121)
      Time format               Spacecraft clock string
      Input time                863834674:28127
      Reference frame           MPO_SERENA_STROFIO+X
      Vector magnitude          Unit
      Coordinate system         Rectangular
 
   WGC will return the following unit vector along the velocity direction,
   deg:
 
      0.10574453
      9.33475590E-06
      0.99439333
 
 
``Mars Express Geometric Event Finding'' Hands-On Lesson Using WGC
--------------------------------------------------------
 
 
Kernels Used
 
   Use the ``SPICE Class - Mars Express Geometric Event Finding Lesson
   Kernels'' kernel set appearing near the bottom of the ``Kernel
   selection:'' menu to do all steps in this lesson.
 
   Make sure to unload the ``Ground Stations Kernels'' kernel set if it is
   pre-loaded by default as this kernel set contains a duplicate definition
   of the ``DSS-14_TOPO'' frame that may trigger a SPICE error if loaded
   together with the lesson kernel set.
 
 
Find View Periods
 
   To find the set of time intervals when the Mars Express (MEX) is visible
   from the DSN station DSS-14, specify/select the following inputs in the
   ``Position Event Finder'' calculation:
 
      Target                      MEX
      Observer                    DSS-14
      Reference frame             DSS-14_TOPO
      Light propagation           To observer
      Light-time algorithm        Converged Newtonian
      Stellar aberration          Corrected for stellar aberration
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2004 MAY 2 to 2004 MAY 6
      Step                        300 seconds
      Coordinate system           Planetocentric
      Coordinate condition        Latitude is greater than 6
      Output time unit            hours
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following interval start and stop times:
 
      2004-05-02 00:00:00.000000 TDB
      2004-05-02 05:35:03.096376 TDB
 
      2004-05-02 16:09:14.078641 TDB
      2004-05-03 05:33:57.257816 TDB
 
      2004-05-03 16:08:02.279561 TDB
      2004-05-04 05:32:50.765340 TDB
 
      2004-05-04 16:06:51.259358 TDB
      2004-05-05 05:31:43.600189 TDB
 
      2004-05-05 16:05:40.994061 TDB
      2004-05-06 00:00:00.000000 TDB
 
   Make sure to save these output intervals in the WGC ``Saved Values''
   area using the ``Save All Intervals'' button to make them available for
   use as input to the next step of the lesson.
 
 
Find Times when Target is Visible
 
   To find the set of time intervals when the Mars Express Orbiter (MEX)
   spacecraft is visible from the DSN station DSS-14 and is not occulted by
   Mars modeled as an ellipsoid, specify/select the following inputs in the
   ``Occultation Event Finder'' calculation:
 
      Occultation type            Any
      Front body                  MARS
      Front body shape            Ellipsoid
      Front body frame            IAU_MARS
      Back body                   MEX
      Back body shape             Point
      Back body frame
      Observer                    DSS-14
      Light propagation           To observer
      Light-time algorithm        Converged Newtonian
      Time system                 TDB
      Time format                 Calendar date and time
      Time windows                ["2004-05-02 00:00:00....
      Step                        300 seconds
      Output time unit            hours
      Complement result window    yes
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   To use the time intervals found by the previous step as the input to
   this calculation, select ``List of Intervals'' in the ``Input times:''
   selector and drag and drop saved intervals from the ``Saved Values''
   area into the empty ``List of intervals:'' box.
 
   WGC will return the following interval start and stop times:
 
      2004-05-02 00:00:00.000000 TDB
      2004-05-02 04:49:30.827635 TDB
 
      2004-05-02 16:09:14.078641 TDB
      2004-05-02 20:00:22.514122 TDB
 
      2004-05-02 21:01:38.222068 TDB
      2004-05-03 03:35:42.256777 TDB
 
      2004-05-03 04:36:42.484694 TDB
      2004-05-03 05:33:57.257816 TDB
 
      2004-05-03 16:08:02.279561 TDB
      2004-05-03 18:46:26.013964 TDB
 
      2004-05-03 19:46:54.618795 TDB
      2004-05-04 02:21:44.562990 TDB
 
      2004-05-04 03:21:56.347988 TDB
      2004-05-04 05:32:50.765340 TDB
 
      2004-05-04 16:06:51.259358 TDB
      2004-05-04 17:32:25.809031 TDB
 
      2004-05-04 18:32:05.975318 TDB
      2004-05-05 01:07:48.264966 TDB
 
      2004-05-05 02:07:11.601765 TDB
      2004-05-05 05:31:43.600189 TDB
 
      2004-05-05 16:05:40.994061 TDB
      2004-05-05 16:18:35.560693 TDB
 
      2004-05-05 17:17:27.717224 TDB
      2004-05-05 23:54:04.672052 TDB
 
   To find the set of time intervals when the Mars Express Orbiter (MEX)
   spacecraft is visible from the DSN station DSS-14 and is not occulted by
   Mars modeled using a DSK shape model, specify/select the following
   inputs in the ``Occultation Event Finder'' calculation:
 
      Occultation type            Any
      Front body                  MARS
      Front body shape            DSK model
      Front body frame            IAU_MARS
      Back body                   MEX
      Back body shape             Point
      Observer                    DSS-14
      Light propagation           To observer
      Light-time algorithm        Converged Newtonian
      Time system                 TDB
      Time format                 Calendar date and time
      Time windows                ["2004-05-02 00:00:00....
      Step                        300 seconds
      Output time unit            hours
      Complement result window    yes
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   To use the time intervals found by the previous step as the input to
   this calculation, select ``List of Intervals'' in the ``Input times:''
   selector and drag and drop saved intervals from the ``Saved Values''
   area into the empty ``List of intervals:'' box.
 
   WGC will return the following interval start and stop times:
 
      2004-05-02 00:00:00.000000 TDB
      2004-05-02 04:49:32.645582 TDB
 
      2004-05-02 16:09:14.078641 TDB
      2004-05-02 20:00:23.980386 TDB
 
      2004-05-02 21:01:43.206810 TDB
      2004-05-03 03:35:44.140275 TDB
 
      2004-05-03 04:36:46.868950 TDB
      2004-05-03 05:33:57.257816 TDB
 
      2004-05-03 16:08:02.279561 TDB
      2004-05-03 18:46:27.306582 TDB
 
      2004-05-03 19:46:59.734382 TDB
      2004-05-04 02:21:46.574959 TDB
 
      2004-05-04 03:22:00.862241 TDB
      2004-05-04 05:32:50.765340 TDB
 
      2004-05-04 16:06:51.259358 TDB
      2004-05-04 17:32:27.118804 TDB
 
      2004-05-04 18:32:11.057061 TDB
      2004-05-05 01:07:50.061373 TDB
 
      2004-05-05 02:07:16.253201 TDB
      2004-05-05 05:31:43.600189 TDB
 
      2004-05-05 16:05:40.994061 TDB
      2004-05-05 16:18:36.994871 TDB
 
      2004-05-05 17:17:32.385773 TDB
      2004-05-05 23:54:06.221724 TDB
 
 
Extra Credit
 
   1. To find times when Mars Express orbiter (MEX) crosses Mars' equator,
   specify/select the following inputs in the ``Position Event Finder''
   calculation:
 
      Target                      MARS EXPRESS
      Observer                    MARS
      Reference frame             IAU_MARS
      Light propagation           No correction
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2004 MAY 02 to 2004 MAY 06
      Step                        300 seconds
      Coordinate system           Planetocentric
      Coordinate condition        Latitude equals 0
      Output time unit            seconds
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following times:
 
      2004-05-02 05:00:08.334792 TDB
      2004-05-02 06:15:13.074957 TDB
      2004-05-02 12:35:14.856242 TDB
      2004-05-02 13:50:09.161841 TDB
      2004-05-02 20:10:24.439170 TDB
      2004-05-02 21:25:10.344246 TDB
      2004-05-03 03:45:26.758446 TDB
      2004-05-03 05:00:04.086901 TDB
      2004-05-03 11:20:32.419618 TDB
      2004-05-03 12:34:57.968562 TDB
      2004-05-03 18:55:34.883629 TDB
      2004-05-03 20:09:53.063063 TDB
      2004-05-04 02:30:35.509603 TDB
      2004-05-04 03:44:42.753445 TDB
      2004-05-04 10:05:41.638033 TDB
      2004-05-04 11:19:38.397433 TDB
      2004-05-04 17:40:41.405725 TDB
      2004-05-04 18:54:31.413477 TDB
      2004-05-05 01:15:45.967991 TDB
      2004-05-05 02:29:25.294886 TDB
      2004-05-05 08:50:53.931352 TDB
      2004-05-05 10:04:26.915886 TDB
      2004-05-05 16:25:58.350272 TDB
      2004-05-05 17:39:23.889937 TDB
 
   2. To find times when Mars Express orbiter (MEX) is at periapsis,
   specify/select the following inputs in the ``Distance Event Finder''
   calculation:
 
      Target                      MARS EXPRESS
      Observer                    MARS
      Light propagation           No correction
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2004 MAY 02 to 2004 MAY 06
      Step                        300 seconds
      Coordinate condition        Distance is local minimum
      Output time unit            seconds
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following times:
 
      2004-05-02 05:57:51.000411 TDB
      2004-05-02 13:32:43.325958 TDB
      2004-05-02 21:07:41.124293 TDB
      2004-05-03 04:42:30.648154 TDB
      2004-05-03 12:17:21.143198 TDB
      2004-05-03 19:52:12.267643 TDB
      2004-05-04 03:26:57.755816 TDB
      2004-05-04 11:01:49.826895 TDB
      2004-05-04 18:36:38.448012 TDB
      2004-05-05 02:11:28.558226 TDB
      2004-05-05 09:46:26.309109 TDB
      2004-05-05 17:21:18.875493 TDB
 
   3. To find times when Mars Express orbiter (MEX) is at apoapsis,
   specify/select the following inputs in the ``Distance Event Finder''
   calculation:
 
      Target                      MARS EXPRESS
      Observer                    MARS
      Light propagation           No correction
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2004 MAY 02 to 2004 MAY 06
      Step                        300 seconds
      Coordinate condition        Distance is local maximum
      Output time unit            seconds
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following times:
 
      2004-05-02 02:10:24.948283 TDB
      2004-05-02 09:45:19.189323 TDB
      2004-05-02 17:20:14.194854 TDB
      2004-05-03 00:55:07.633360 TDB
      2004-05-03 08:29:57.890652 TDB
      2004-05-03 16:04:48.524492 TDB
      2004-05-03 23:39:36.745574 TDB
      2004-05-04 07:14:25.662870 TDB
      2004-05-04 14:49:15.904704 TDB
      2004-05-04 22:24:05.351784 TDB
      2004-05-05 05:58:59.270665 TDB
      2004-05-05 13:33:54.433201 TDB
      2004-05-05 21:08:50.211003 TDB
 
 
``ExoMars-16 TGO Geometric Event Finding'' Hands-On Lesson Using WGC
--------------------------------------------------------
 
 
Kernels Used
 
   Use the ``SPICE Class - ExoMars 2016 Geometric Event Finding Lesson
   Kernels'' kernel set appearing near the bottom of the ``Kernel
   selection:'' menu to do all steps in this lesson.
 
 
Find View Periods
 
   To find the set of time intervals when the ExoMars-16 TGO (TGO) is
   visible from the ESA station NEW_NORCIA, specify/select the following
   inputs in the ``Position Event Finder'' calculation:
 
      Target                      EXOMARS 2016 TGO
      Observer                    NEW_NORCIA
      Reference frame             NEW_NORCIA_TOPO
      Light propagation           To observer
      Light-time algorithm        Converged Newtonian
      Stellar aberration          Corrected for stellar aberration
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2018 JUN 10 to 2018 JUN 14
      Step                        300 seconds
      Coordinate system           Planetocentric
      Coordinate condition        Latitude is greater than 6
      Output time unit            hours
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following interval start and stop times:
 
      2018-06-10 00:00:00.000000 TDB
      2018-06-10 02:11:17.355621 TDB
 
      2018-06-10 13:19:58.777464 TDB
      2018-06-11 02:08:16.008548 TDB
 
      2018-06-11 13:16:50.542539 TDB
      2018-06-12 02:05:12.548825 TDB
 
      2018-06-12 13:13:38.573032 TDB
      2018-06-13 02:02:06.618874 TDB
 
      2018-06-13 13:10:23.432464 TDB
      2018-06-14 00:00:00.000000 TDB
 
   Make sure to save these output intervals in the WGC ``Saved Values''
   area using the ``Save All Intervals'' button to make them available for
   use as input to the next step of the lesson.
 
 
Find Times when Target is Visible
 
   To find the set of time intervals when the ExoMars-16 TGO Orbiter (TGO)
   spacecraft is visible from the ESA station NEW_NORCIA and and is not
   occulted by Mars modeled as an ellipsoid, specify/select the following
   inputs in the ``Occultation Event Finder'' calculation:
 
      Occultation type            Any
      Front body                  MARS
      Front body shape            Ellipsoid
      Front body frame            IAU_MARS
      Back body                   EXOMARS 2016 TGO
      Back body shape             Point
      Observer                    NEW_NORCIA
      Light propagation           To observer
      Light-time algorithm        Converged Newtonian
      Time system                 TDB
      Time format                 Calendar date and time
      Time windows                ["2018-06-10 00:00:00....
      Step                        300 seconds
      Output time unit            hours
      Complement result window    yes
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   To use the time intervals found by the previous step as the input to
   this calculation, select ``List of Intervals'' in the ``Input times:''
   selector and drag and drop saved intervals from the ``Saved Values''
   area into the empty ``List of intervals:'' box.
 
   WGC will return the following interval start and stop times:
 
      2018-06-10 00:00:00.000000 TDB
      2018-06-10 01:00:30.640614 TDB
 
      2018-06-10 01:41:03.610048 TDB
      2018-06-10 02:11:17.355621 TDB
 
      2018-06-10 13:28:28.785788 TDB
      2018-06-10 14:45:38.197853 TDB
 
      2018-06-10 15:26:21.981505 TDB
      2018-06-10 16:43:32.192863 TDB
 
      2018-06-10 17:24:17.290058 TDB
      2018-06-10 18:41:27.535612 TDB
 
      2018-06-10 19:22:13.628023 TDB
      2018-06-10 20:39:21.785693 TDB
 
      2018-06-10 21:20:08.856427 TDB
      2018-06-10 22:37:12.445420 TDB
 
      2018-06-10 23:18:00.834325 TDB
      2018-06-11 00:35:01.034340 TDB
 
      2018-06-11 01:15:50.883961 TDB
      2018-06-11 02:08:16.008548 TDB
 
      2018-06-11 13:16:50.542539 TDB
      2018-06-11 14:20:09.789544 TDB
 
      2018-06-11 15:01:08.370780 TDB
      2018-06-11 16:18:03.385855 TDB
 
      2018-06-11 16:59:03.014503 TDB
      2018-06-11 18:15:58.739454 TDB
 
      2018-06-11 18:56:59.199542 TDB
      2018-06-11 20:13:54.308303 TDB
 
      2018-06-11 20:54:55.301168 TDB
      2018-06-11 22:11:47.045226 TDB
 
      2018-06-11 22:52:48.925002 TDB
      2018-06-12 00:09:35.868266 TDB
 
      2018-06-12 00:50:39.046685 TDB
      2018-06-12 02:05:12.548825 TDB
 
      2018-06-12 13:13:38.573032 TDB
      2018-06-12 13:54:43.524958 TDB
 
      2018-06-12 14:35:54.054008 TDB
      2018-06-12 15:52:36.256662 TDB
 
      2018-06-12 16:33:47.502777 TDB
      2018-06-12 17:50:30.988537 TDB
 
      2018-06-12 18:31:42.896589 TDB
      2018-06-12 19:48:26.827964 TDB
 
      2018-06-12 20:29:39.039169 TDB
      2018-06-12 21:46:20.933464 TDB
 
      2018-06-12 22:27:33.596215 TDB
      2018-06-12 23:44:11.473471 TDB
 
      2018-06-13 00:25:24.992296 TDB
      2018-06-13 01:42:00.777360 TDB
 
      2018-06-13 13:10:23.432464 TDB
      2018-06-13 13:29:19.789157 TDB
 
      2018-06-13 14:10:38.985039 TDB
      2018-06-13 15:27:11.882834 TDB
 
      2018-06-13 16:08:31.566611 TDB
      2018-06-13 17:25:06.068241 TDB
 
      2018-06-13 18:06:26.219824 TDB
      2018-06-13 19:23:01.820444 TDB
 
      2018-06-13 20:04:22.175372 TDB
      2018-06-13 21:20:57.296111 TDB
 
      2018-06-13 22:02:17.650959 TDB
      2018-06-13 23:18:49.624491 TDB
 
   To find the set of time intervals when the ExoMars-16 TGO Orbiter (TGO)
   spacecraft is visible from the ESA station NEW_NORCIA and and is not
   occulted by Mars modeled using a DSK shape model, specify/select the
   following inputs in the ``Occultation Event Finder'' calculation:
 
      Occultation type            Any
      Front body                  MARS
      Front body shape            DSK model
      Front body frame            IAU_MARS
      Back body                   EXOMARS 2016 TGO
      Back body shape             Point
      Observer                    NEW_NORCIA
      Light propagation           To observer
      Light-time algorithm        Converged Newtonian
      Time system                 TDB
      Time format                 Calendar date and time
      Time windows                ["2018-06-10 00:00:00....
      Step                        300 seconds
      Output time unit            hours
      Complement result window    yes
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   To use the time intervals found by the previous step as the input to
   this calculation, select ``List of Intervals'' in the ``Input times:''
   selector and drag and drop saved intervals from the ``Saved Values''
   area into the empty ``List of intervals:'' box.
 
   WGC will return the following interval start and stop times:
 
      2018-06-10 00:00:00.000000 TDB
      2018-06-10 01:00:28.220807 TDB
 
      2018-06-10 01:41:01.646917 TDB
      2018-06-10 02:11:17.355621 TDB
 
      2018-06-10 13:28:26.224303 TDB
      2018-06-10 14:45:35.493195 TDB
 
      2018-06-10 15:26:19.616482 TDB
      2018-06-10 16:43:28.927026 TDB
 
      2018-06-10 17:24:15.708129 TDB
      2018-06-10 18:41:24.797353 TDB
 
      2018-06-10 19:22:12.239603 TDB
      2018-06-10 20:39:19.310010 TDB
 
      2018-06-10 21:20:07.177145 TDB
      2018-06-10 22:37:09.488415 TDB
 
      2018-06-10 23:17:58.789177 TDB
      2018-06-11 00:34:58.698530 TDB
 
      2018-06-11 01:15:48.932135 TDB
      2018-06-11 02:08:16.008548 TDB
 
      2018-06-11 13:16:50.542539 TDB
      2018-06-11 14:20:07.002550 TDB
 
      2018-06-11 15:01:05.889750 TDB
      2018-06-11 16:18:00.245245 TDB
 
      2018-06-11 16:59:00.815555 TDB
      2018-06-11 18:15:55.713823 TDB
 
      2018-06-11 18:56:57.742755 TDB
      2018-06-11 20:13:51.980832 TDB
 
      2018-06-11 20:54:53.740948 TDB
      2018-06-11 22:11:44.029460 TDB
 
      2018-06-11 22:52:47.021765 TDB
      2018-06-12 00:09:33.513615 TDB
 
      2018-06-12 00:50:37.057576 TDB
      2018-06-12 02:05:12.548825 TDB
 
      2018-06-12 13:13:38.573032 TDB
      2018-06-12 13:54:41.265138 TDB
 
      2018-06-12 14:35:51.639820 TDB
      2018-06-12 15:52:34.091993 TDB
 
      2018-06-12 16:33:45.105220 TDB
      2018-06-12 17:50:29.020626 TDB
 
      2018-06-12 18:31:41.100405 TDB
      2018-06-12 19:48:23.878666 TDB
 
      2018-06-12 20:29:37.591528 TDB
      2018-06-12 21:46:18.430557 TDB
 
      2018-06-12 22:27:31.911087 TDB
      2018-06-12 23:44:08.681952 TDB
 
      2018-06-13 00:25:22.967320 TDB
      2018-06-13 01:41:58.417366 TDB
 
      2018-06-13 13:10:23.432464 TDB
      2018-06-13 13:29:18.021452 TDB
 
      2018-06-13 14:10:36.866862 TDB
      2018-06-13 15:27:09.686654 TDB
 
      2018-06-13 16:08:29.188852 TDB
      2018-06-13 17:25:04.013047 TDB
 
      2018-06-13 18:06:23.940576 TDB
      2018-06-13 19:22:59.754402 TDB
 
      2018-06-13 20:04:20.668606 TDB
      2018-06-13 21:20:54.998971 TDB
 
      2018-06-13 22:02:16.162693 TDB
      2018-06-13 23:18:47.458050 TDB
 
 
Extra Credit
 
   1. To find times when ExoMars-16 TGO (TGO) crosses Mars' equator,
   specify/select the following inputs in the ``Position Event Finder''
   calculation:
 
      Target                      EXOMARS 2016 TGO
      Observer                    MARS
      Reference frame             IAU_MARS
      Light propagation           No correction
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2018 JUN 10 to 2018 JUN 11
      Step                        300 seconds
      Coordinate system           Planetocentric
      Coordinate condition        Latitude equals 0
      Output time unit            seconds
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following times:
 
      2018-06-10 00:14:08.836580 TDB
      2018-06-10 01:12:34.582095 TDB
      2018-06-10 02:12:00.375370 TDB
      2018-06-10 03:10:28.808573 TDB
      2018-06-10 04:09:53.955311 TDB
      2018-06-10 05:08:23.919392 TDB
      2018-06-10 06:07:48.630669 TDB
      2018-06-10 07:06:17.539430 TDB
      2018-06-10 08:05:42.659963 TDB
      2018-06-10 09:04:09.120521 TDB
      2018-06-10 10:03:34.270188 TDB
      2018-06-10 11:01:59.269625 TDB
      2018-06-10 12:01:22.866520 TDB
      2018-06-10 12:59:49.352117 TDB
      2018-06-10 13:59:13.289772 TDB
      2018-06-10 14:57:41.242004 TDB
      2018-06-10 15:57:07.576976 TDB
      2018-06-10 16:55:35.266038 TDB
      2018-06-10 17:55:02.773235 TDB
      2018-06-10 18:53:30.271499 TDB
      2018-06-10 19:52:56.383285 TDB
      2018-06-10 20:51:23.966229 TDB
      2018-06-10 21:50:47.729319 TDB
      2018-06-10 22:49:14.385397 TDB
      2018-06-10 23:48:37.583974 TDB
 
   2. To find times when ExoMars-16 TGO (TGO) is at periapsis,
   specify/select the following inputs in the ``Distance Event Finder''
   calculation:
 
      Target                      EXOMARS 2016 TGO
      Observer                    MARS
      Light propagation           No correction
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2018 JUN 10 to 2018 JUN 11
      Step                        300 seconds
      Coordinate condition        Distance is local minimum
      Output time unit            seconds
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following times:
 
      2018-06-10 00:43:06.357819 TDB
      2018-06-10 02:40:47.168872 TDB
      2018-06-10 04:38:45.496250 TDB
      2018-06-10 06:36:32.706773 TDB
      2018-06-10 08:34:10.548681 TDB
      2018-06-10 10:31:49.108636 TDB
      2018-06-10 12:29:20.342207 TDB
      2018-06-10 14:27:07.089996 TDB
      2018-06-10 16:25:36.081463 TDB
      2018-06-10 18:24:02.653942 TDB
      2018-06-10 20:22:23.184793 TDB
      2018-06-10 22:20:12.453735 TDB
 
   3. To find times when ExoMars-16 TGO (TGO) is at apoapsis,
   specify/select the following inputs in the ``Distance Event Finder''
   calculation:
 
      Target                      EXOMARS 2016 TGO
      Observer                    MARS
      Light propagation           No correction
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2018 JUN 10 to 2018 JUN 11
      Step                        300 seconds
      Coordinate condition        Distance is local maximum
      Output time unit            seconds
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following times:
 
      2018-06-10 01:41:44.632145 TDB
      2018-06-10 03:39:31.106999 TDB
      2018-06-10 05:37:22.115251 TDB
      2018-06-10 07:34:59.674318 TDB
      2018-06-10 09:32:25.708394 TDB
      2018-06-10 11:29:47.945538 TDB
      2018-06-10 13:27:30.200636 TDB
      2018-06-10 15:26:02.524463 TDB
      2018-06-10 17:24:37.842993 TDB
      2018-06-10 19:23:11.265220 TDB
      2018-06-10 21:21:13.530306 TDB
      2018-06-10 23:18:56.796575 TDB
 
 
``KPLO Geometric Event Finding'' Hands-On Lesson Using WGC
--------------------------------------------------------
 
 
Kernels Used
 
   Use the ``SPICE Class - KPLO Geometric Event Finding Lesson Kernels''
   kernel set appearing near the bottom of the ``Kernel selection:'' menu
   to do all steps in this lesson.
 
 
Find View Periods
 
   To find the set of time intervals when the KPLO is visible from the KARI
   station KDSA, specify/select the following inputs in the ``Position
   Event Finder'' calculation:
 
      Target                      KOREA PATHFINDER LUNAR ORBITER
      Observer                    KDSA
      Reference frame             KDSA_TOPO
      Light propagation           To observer
      Light-time algorithm        Converged Newtonian
      Stellar aberration          Corrected for stellar aberration
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2021 JAN 02 to 2021 JAN 04 TDB
      Step                        300 seconds
      Coordinate system           Planetocentric
      Coordinate condition        Latitude is greater than 6
      Output time unit            hours
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following interval start and stop times:
 
      2021-01-02 00:00:00.000000 TDB
      2021-01-02 00:29:04.809104 TDB
 
      2021-01-02 12:09:44.219078 TDB
      2021-01-03 01:06:51.294946 TDB
 
      2021-01-03 13:14:11.953416 TDB
      2021-01-04 00:00:00.000000 TDB
 
   Make sure to save these output intervals in the WGC ``Saved Values''
   area using the ``Save All Intervals'' button to make them available for
   use as input to the next step of the lesson.
 
 
Find Times when Target is Visible
 
   To find the set of time intervals when the KPLO Orbiter spacecraft is
   visible from the KARI station KDSA and and is not occulted by Moon
   modeled as an ellipsoid, specify/select the following inputs in the
   ``Occultation Event Finder'' calculation:
 
      Occultation type            Any
      Front body                  MOON
      Front body shape            Ellipsoid
      Front body frame            MOON_ME
      Back body                   KOREA PATHFINDER LUNAR ORBITER
      Back body shape             Point
      Observer                    KDSA
      Light propagation           To observer
      Light-time algorithm        Converged Newtonian
      Time system                 TDB
      Time format                 Calendar date and time
      Time windows                ["2021-01-02 00:00:00...
      Step                        300 seconds
      Output time unit            hours
      Complement result window    yes
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   To use the time intervals found by the previous step as the input to
   this calculation, select ``List of Intervals'' in the ``Input times:''
   selector and drag and drop saved intervals from the ``Saved Values''
   area into the empty ``List of intervals:'' box.
 
   WGC will return the following interval start and stop times:
 
      2021-01-02 00:00:00.000000 TDB
      2021-01-02 00:10:09.889149 TDB
 
      2021-01-02 12:40:16.709927 TDB
      2021-01-02 13:53:22.951804 TDB
 
      2021-01-02 14:38:06.490360 TDB
      2021-01-02 15:51:01.342268 TDB
 
      2021-01-02 16:35:53.098803 TDB
      2021-01-02 17:48:38.156533 TDB
 
      2021-01-02 18:33:36.932715 TDB
      2021-01-02 19:46:13.245471 TDB
 
      2021-01-02 20:31:18.977103 TDB
      2021-01-02 21:43:47.009069 TDB
 
      2021-01-02 22:29:00.574638 TDB
      2021-01-02 23:41:20.248180 TDB
 
      2021-01-03 00:26:43.022041 TDB
      2021-01-03 01:06:51.294946 TDB
 
      2021-01-03 13:14:11.953416 TDB
      2021-01-03 13:24:44.929522 TDB
 
      2021-01-03 14:11:13.658468 TDB
      2021-01-03 15:22:24.978150 TDB
 
      2021-01-03 16:08:57.996438 TDB
      2021-01-03 17:20:04.038775 TDB
 
      2021-01-03 18:06:40.377391 TDB
      2021-01-03 19:17:42.133447 TDB
 
      2021-01-03 20:04:21.409086 TDB
      2021-01-03 21:15:19.693724 TDB
 
      2021-01-03 22:02:02.068830 TDB
      2021-01-03 23:12:57.440831 TDB
 
      2021-01-03 23:59:43.429772 TDB
      2021-01-04 00:00:00.000000 TDB
 
   To find the set of time intervals when the KPLO Orbiter spacecraft is
   visible from the KARI station KDSA and and is not occulted by Moon
   modeled using a DSK shape model, specify/select the following inputs in
   the ``Occultation Event Finder'' calculation:
 
      Occultation type            Any
      Front body                  MOON
      Front body shape            DSK model
      Front body frame            MOON_ME
      Back body                   KOREA PATHFINDER LUNAR ORBITER
      Back body shape             Point
      Observer                    KDSA
      Light propagation           To observer
      Light-time algorithm        Converged Newtonian
      Time system                 TDB
      Time format                 Calendar date and time
      Time windows                ["2021-01-02 00:00:00...
      Step                        300 seconds
      Output time unit            hours
      Complement result window    yes
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   To use the time intervals found by the previous step as the input to
   this calculation, select ``List of Intervals'' in the ``Input times:''
   selector and drag and drop saved intervals from the ``Saved Values''
   area into the empty ``List of intervals:'' box.
 
   WGC will return the following interval start and stop times:
 
      2021-01-02 00:00:00.000000 TDB
      2021-01-02 00:10:08.006832 TDB
 
      2021-01-02 12:40:16.852087 TDB
      2021-01-02 13:53:27.473483 TDB
 
      2021-01-02 14:38:06.251356 TDB
      2021-01-02 15:51:03.685211 TDB
 
      2021-01-02 16:35:52.094231 TDB
      2021-01-02 17:48:37.725860 TDB
 
      2021-01-02 18:33:36.119642 TDB
      2021-01-02 19:46:15.165413 TDB
 
      2021-01-02 20:31:18.110644 TDB
      2021-01-02 21:43:51.889714 TDB
 
      2021-01-02 22:28:59.525035 TDB
      2021-01-02 23:41:26.087095 TDB
 
      2021-01-03 00:26:41.518075 TDB
      2021-01-03 01:06:51.294946 TDB
 
      2021-01-03 13:14:11.953416 TDB
      2021-01-03 13:24:47.451517 TDB
 
      2021-01-03 14:11:12.626333 TDB
      2021-01-03 15:22:28.682591 TDB
 
      2021-01-03 16:08:56.940982 TDB
      2021-01-03 17:20:08.465709 TDB
 
      2021-01-03 18:06:39.012820 TDB
      2021-01-03 19:17:46.193336 TDB
 
      2021-01-03 20:04:20.411973 TDB
      2021-01-03 21:15:23.606861 TDB
 
      2021-01-03 22:02:01.131969 TDB
      2021-01-03 23:12:59.851984 TDB
 
      2021-01-03 23:59:42.474125 TDB
      2021-01-04 00:00:00.000000 TDB
 
 
Extra Credit
 
   1. To find times when KPLO crosses Moon' equator, specify/select the
   following inputs in the ``Position Event Finder'' calculation:
 
      Target                      KOREA PATHFINDER LUNAR ORBITER
      Observer                    MOON
      Reference frame             MOON_ME
      Light propagation           No correction
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2021 JAN 02 to 2021 JAN 03
      Step                        300 seconds
      Coordinate system           Planetocentric
      Coordinate condition        Latitude equals 0
      Output time unit            seconds
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following times:
 
      2021-01-02 00:29:09.291260 TDB
      2021-01-02 01:28:07.739313 TDB
      2021-01-02 02:26:53.378996 TDB
      2021-01-02 03:25:51.718417 TDB
      2021-01-02 04:24:37.370435 TDB
      2021-01-02 05:23:35.637643 TDB
      2021-01-02 06:22:21.229758 TDB
      2021-01-02 07:21:19.488355 TDB
      2021-01-02 08:20:04.908620 TDB
      2021-01-02 09:19:03.268286 TDB
      2021-01-02 10:17:48.394045 TDB
      2021-01-02 11:16:46.997406 TDB
      2021-01-02 12:15:31.710021 TDB
      2021-01-02 13:14:30.717714 TDB
      2021-01-02 14:13:14.874535 TDB
      2021-01-02 15:12:14.473830 TDB
      2021-01-02 16:10:57.866823 TDB
      2021-01-02 17:09:58.289834 TDB
      2021-01-02 18:08:40.644274 TDB
      2021-01-02 19:07:42.160572 TDB
      2021-01-02 20:06:23.192173 TDB
      2021-01-02 21:05:26.057974 TDB
      2021-01-02 22:04:05.537612 TDB
      2021-01-02 23:03:09.942854 TDB
 
   2. To find times when KPLO is at periapsis, specify/select the following
   inputs in the ``Distance Event Finder'' calculation:
 
      Target                      KOREA PATHFINDER LUNAR ORBITER
      Observer                    MOON
      Light propagation           No correction
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2021 JAN 02 to 2021 JAN 03
      Step                        300 seconds
      Coordinate condition        Distance is local minimum
      Output time unit            seconds
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following times:
 
      2021-01-02 01:30:03.252209 TDB
      2021-01-02 03:27:47.175008 TDB
      2021-01-02 05:25:32.458516 TDB
      2021-01-02 07:23:19.666917 TDB
      2021-01-02 09:21:09.488858 TDB
      2021-01-02 11:19:02.272580 TDB
      2021-01-02 13:16:58.197678 TDB
      2021-01-02 15:14:57.534376 TDB
      2021-01-02 17:13:00.573722 TDB
      2021-01-02 19:11:07.149724 TDB
      2021-01-02 21:09:16.134309 TDB
      2021-01-02 23:07:26.025982 TDB
 
   3. To find times when KPLO is at apoapsis, specify/select the following
   inputs in the ``Distance Event Finder'' calculation:
 
      Target                      KOREA PATHFINDER LUNAR ORBITER
      Observer                    MOON
      Light propagation           No correction
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2021 JAN 02 to 2021 JAN 03
      Step                        300 seconds
      Coordinate condition        Distance is local maximum
      Output time unit            seconds
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following times:
 
      2021-01-02 00:31:23.997068 TDB
      2021-01-02 02:29:07.494822 TDB
      2021-01-02 04:26:51.565647 TDB
      2021-01-02 06:24:36.779707 TDB
      2021-01-02 08:22:24.045804 TDB
      2021-01-02 10:20:13.799654 TDB
      2021-01-02 12:18:06.012411 TDB
      2021-01-02 14:16:00.876052 TDB
      2021-01-02 16:13:59.150197 TDB
      2021-01-02 18:12:01.620695 TDB
      2021-01-02 20:10:08.021442 TDB
      2021-01-02 22:08:16.917912 TDB
 
 
``BepiColombo MPO Geometric Event Finding'' Hands-On Lesson Using WGC
--------------------------------------------------------
 
 
Kernels Used
 
   Use the ``SPICE Class - BepiColombo MPO Geometric Event Finding Lesson
   Kernels'' kernel set appearing near the bottom of the ``Kernel
   selection:'' menu to do all steps in this lesson.
 
 
Find View Periods
 
   To find the set of time intervals when the BepiColombo MPO (MPO) is
   visible from the ESA station NEW_NORCIA, specify/select the following
   inputs in the ``Position Event Finder'' calculation:
 
      Target                      BEPICOLOMBO MPO
      Observer                    NEW_NORCIA
      Reference frame             NEW_NORCIA_TOPO
      Light propagation           To observer
      Light-time algorithm        Converged Newtonian
      Stellar aberration          Corrected for stellar aberration
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2027 JAN 03 to 2027 JAN 06
      Step                        300 seconds
      Coordinate system           Planetocentric
      Coordinate condition        Latitude is greater than 6
      Output time unit            hours
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following interval start and stop times:
 
      2027-01-03 00:00:00.000000 TDB
      2027-01-03 10:58:25.063666 TDB
 
      2027-01-03 21:55:08.488015 TDB
      2027-01-04 11:01:14.279503 TDB
 
      2027-01-04 21:58:41.333765 TDB
      2027-01-05 11:04:00.020897 TDB
 
      2027-01-05 22:02:18.477689 TDB
      2027-01-06 00:00:00.000000 TDB
 
   Make sure to save these output intervals in the WGC ``Saved Values''
   area using the ``Save All Intervals'' button to make them available for
   use as input to the next step of the lesson.
 
 
Find Times when Target is Visible
 
   To find the set of time intervals when the BepiColombo MPO Orbiter (MPO)
   spacecraft is visible from the ESA station NEW_NORCIA and and is not
   occulted by MERCURY modeled as an ellipsoid, specify/select the
   following inputs in the ``Occultation Event Finder'' calculation:
 
      Occultation type            Any
      Front body                  MERCURY
      Front body shape            Ellipsoid
      Front body frame            IAU_MERCURY
      Back body                   BEPICOLOMBO MPO
      Back body shape             Point
      Observer                    NEW_NORCIA
      Light propagation           To observer
      Light-time algorithm        Converged Newtonian
      Time system                 TDB
      Time format                 Calendar date and time
      Time windows                ["2027-01-03 00:00:00....
      Step                        300 seconds
      Output time unit            hours
      Complement result window    yes
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   To use the time intervals found by the previous step as the input to
   this calculation, select ``List of Intervals'' in the ``Input times:''
   selector and drag and drop saved intervals from the ``Saved Values''
   area into the empty ``List of intervals:'' box.
 
   WGC will return the following interval start and stop times:
 
      2027-01-03 00:00:00.000000 TDB
      2027-01-03 01:28:03.419233 TDB
 
      2027-01-03 02:00:42.993632 TDB
      2027-01-03 03:49:50.750893 TDB
 
      2027-01-03 04:22:20.803992 TDB
      2027-01-03 06:11:38.050911 TDB
 
      2027-01-03 06:43:58.528879 TDB
      2027-01-03 08:33:25.499611 TDB
 
      2027-01-03 09:05:36.070506 TDB
      2027-01-03 10:55:12.991735 TDB
 
      2027-01-03 21:55:08.488015 TDB
      2027-01-03 22:44:11.490099 TDB
 
      2027-01-03 23:15:19.552983 TDB
      2027-01-04 01:05:59.339076 TDB
 
      2027-01-04 01:36:56.572342 TDB
      2027-01-04 03:27:47.253162 TDB
 
      2027-01-04 03:58:33.411659 TDB
      2027-01-04 05:49:35.238120 TDB
 
      2027-01-04 06:20:10.165230 TDB
      2027-01-04 08:11:23.310135 TDB
 
      2027-01-04 08:41:46.813607 TDB
      2027-01-04 10:33:11.480288 TDB
 
      2027-01-04 21:58:41.333765 TDB
      2027-01-04 22:22:13.911999 TDB
 
      2027-01-04 22:51:24.368524 TDB
      2027-01-05 00:44:02.576224 TDB
 
      2027-01-05 01:13:00.256137 TDB
      2027-01-05 03:05:51.406811 TDB
 
      2027-01-05 03:34:36.025883 TDB
      2027-01-05 05:27:40.260241 TDB
 
      2027-01-05 05:56:11.727894 TDB
      2027-01-05 07:49:29.298129 TDB
 
      2027-01-05 08:17:47.213618 TDB
      2027-01-05 10:11:18.377919 TDB
 
      2027-01-05 10:39:22.574622 TDB
      2027-01-05 11:04:00.020897 TDB
 
      2027-01-05 22:27:17.183790 TDB
      2027-01-06 00:00:00.000000 TDB
 
   To find the set of time intervals when the BepiColombo MPO Orbiter (MPO)
   spacecraft is visible from the ESA station NEW_NORCIA and and is not
   occulted by MERCURY modeled using a DSK shape model, specify/select the
   following inputs in the ``Occultation Event Finder'' calculation:
 
      Occultation type            Any
      Front body                  MERCURY
      Front body shape            DSK model
      Front body frame            IAU_MERCURY
      Back body                   BEPICOLOMBO MPO
      Back body shape             Point
      Observer                    NEW_NORCIA
      Light propagation           To observer
      Light-time algorithm        Converged Newtonian
      Time system                 TDB
      Time format                 Calendar date and time
      Time windows                ["2027-01-03 00:00:00....
      Step                        300 seconds
      Output time unit            hours
      Complement result window    yes
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   To use the time intervals found by the previous step as the input to
   this calculation, select ``List of Intervals'' in the ``Input times:''
   selector and drag and drop saved intervals from the ``Saved Values''
   area into the empty ``List of intervals:'' box.
 
   WGC will return the following interval start and stop times:
 
      2027-01-03 00:00:00.000000 TDB
      2027-01-03 01:28:03.202274 TDB
 
      2027-01-03 02:00:43.226282 TDB
      2027-01-03 03:49:50.589325 TDB
 
      2027-01-03 04:22:21.167426 TDB
      2027-01-03 06:11:37.927914 TDB
 
      2027-01-03 06:43:58.803080 TDB
      2027-01-03 08:33:25.452286 TDB
 
      2027-01-03 09:05:36.483005 TDB
      2027-01-03 10:55:13.005765 TDB
 
      2027-01-03 21:55:08.488015 TDB
      2027-01-03 22:44:11.836443 TDB
 
      2027-01-03 23:15:20.564990 TDB
      2027-01-04 01:05:59.788947 TDB
 
      2027-01-04 01:36:56.903679 TDB
      2027-01-04 03:27:47.794713 TDB
 
      2027-01-04 03:58:33.685170 TDB
      2027-01-04 05:49:35.857104 TDB
 
      2027-01-04 06:20:10.819543 TDB
      2027-01-04 08:11:23.843362 TDB
 
      2027-01-04 08:41:47.399395 TDB
      2027-01-04 10:33:12.291393 TDB
 
      2027-01-04 21:58:41.333765 TDB
      2027-01-04 22:22:13.969382 TDB
 
      2027-01-04 22:51:24.088513 TDB
      2027-01-05 00:44:02.498240 TDB
 
      2027-01-05 01:13:00.056223 TDB
      2027-01-05 03:05:51.377268 TDB
 
      2027-01-05 03:34:36.194296 TDB
      2027-01-05 05:27:40.400567 TDB
 
      2027-01-05 05:56:11.995943 TDB
      2027-01-05 07:49:29.743608 TDB
 
      2027-01-05 08:17:47.173986 TDB
      2027-01-05 10:11:18.893303 TDB
 
      2027-01-05 10:39:22.690895 TDB
      2027-01-05 11:04:00.020897 TDB
 
      2027-01-05 22:27:17.436008 TDB
      2027-01-06 00:00:00.000000 TDB
 
 
Extra Credit
 
   1. To find times when BepiColombo MPO (MPO) crosses MERCURY' equator,
   specify/select the following inputs in the ``Position Event Finder''
   calculation:
 
      Target                      BEPICOLOMBO MPO
      Observer                    MERCURY
      Reference frame             IAU_MERCURY
      Light propagation           No correction
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2027 JAN 03 to 2027 JAN 04
      Step                        300 seconds
      Coordinate system           Planetocentric
      Coordinate condition        Latitude equals 0
      Output time unit            seconds
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following times:
 
      2027-01-03 00:21:02.744334 TDB
      2027-01-03 01:34:39.885957 TDB
      2027-01-03 02:42:45.780223 TDB
      2027-01-03 03:56:22.917048 TDB
      2027-01-03 05:04:28.849131 TDB
      2027-01-03 06:18:06.007358 TDB
      2027-01-03 07:26:11.888263 TDB
      2027-01-03 08:39:49.081587 TDB
      2027-01-03 09:47:54.901012 TDB
      2027-01-03 11:01:32.084351 TDB
      2027-01-03 12:09:37.930329 TDB
      2027-01-03 13:23:15.135888 TDB
      2027-01-03 14:31:20.939808 TDB
      2027-01-03 15:44:58.128865 TDB
      2027-01-03 16:53:03.959515 TDB
      2027-01-03 18:06:41.171174 TDB
      2027-01-03 19:14:46.962115 TDB
      2027-01-03 20:28:24.150065 TDB
      2027-01-03 21:36:29.935243 TDB
      2027-01-03 22:50:07.114962 TDB
      2027-01-03 23:58:12.944905 TDB
 
   2. To find times when BepiColombo MPO (MPO) is at periapsis,
   specify/select the following inputs in the ``Distance Event Finder''
   calculation:
 
      Target                      BEPICOLOMBO MPO
      Observer                    MERCURY
      Light propagation           No correction
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2027 JAN 03 to 2027 JAN 04
      Step                        300 seconds
      Coordinate condition        Distance is local minimum
      Output time unit            seconds
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following times:
 
      2027-01-03 00:18:33.937597 TDB
      2027-01-03 02:40:16.998455 TDB
      2027-01-03 05:01:59.964812 TDB
      2027-01-03 07:23:43.026843 TDB
      2027-01-03 09:45:25.991310 TDB
      2027-01-03 12:07:09.042682 TDB
      2027-01-03 14:28:52.095744 TDB
      2027-01-03 16:50:35.082444 TDB
      2027-01-03 19:12:18.042779 TDB
      2027-01-03 21:34:01.097809 TDB
      2027-01-03 23:55:44.079910 TDB
 
   3. To find times when BepiColombo MPO (MPO) is at apoapsis,
   specify/select the following inputs in the ``Distance Event Finder''
   calculation:
 
      Target                      BEPICOLOMBO MPO
      Observer                    MERCURY
      Light propagation           No correction
      Time system                 TDB
      Time format                 Calendar date and time
      Time range                  2027 JAN 03 to 2027 JAN 04
      Step                        300 seconds
      Coordinate condition        Distance is local maximum
      Output time unit            seconds
      Complement result window    no
      Result interval adjustment  No adjustment
      Result interval filtering   No filtering
 
   WGC will return the following times:
 
      2027-01-03 01:29:25.529845 TDB
      2027-01-03 03:51:08.495185 TDB
      2027-01-03 06:12:51.561811 TDB
      2027-01-03 08:34:34.611548 TDB
      2027-01-03 10:56:17.595681 TDB
      2027-01-03 13:18:00.653133 TDB
      2027-01-03 15:39:43.611529 TDB
      2027-01-03 18:01:26.677944 TDB
      2027-01-03 20:23:09.638216 TDB
      2027-01-03 22:44:52.618672 TDB
 
 
``Binary PCK'' Hands-On Lesson Using WGC
--------------------------------------------------------
 
 
Moon rotation (mrotat)
 
   Use the ``SPICE Class - Binary PCK Lesson Kernels (Moon)'' kernel set
   appearing near the bottom of the ``Kernel selection:'' menu to do this
   step in this lesson.
 
   To compute the Moon-Earth direction using the low accuracy PCK and the
   IAU_MOON frame, specify/select the following inputs in the ``State
   Vector'' calculation:
 
      Target type               Object
      Target                    EARTH
      Observer type             Object
      Observer                  MOON
      Reference frame           IAU_MOON
      Light propagation         To observer
      Light-time algorithm      Converged Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2007 JAN 1 00:00:00
      State representation      Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      3.61310222
      -6.43834182
 
   To compute the Moon-Earth direction using a high accuracy PCK and the
   MOON_ME frame, specify/select the following inputs in the ``State
   Vector'' calculation:
 
      Target type               Object
      Target                    EARTH
      Observer type             Object
      Observer                  MOON
      Reference frame           MOON_ME
      Light propagation         To observer
      Light-time algorithm      Converged Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2007 JAN 1 00:00:00
      State representation      Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      3.61122841
      -6.43950148
 
   WGC cannot compute angular separation between the Moon-Earth direction
   vectors in the IAU_MOON and MOON_ME frames.
 
   To compute the Moon-Earth direction using a high accuracy PCK and the
   MOON_PA frame, specify/select the following inputs in the ``State
   Vector'' calculation:
 
      Target type               Object
      Target                    EARTH
      Observer type             Object
      Observer                  MOON
      Reference frame           MOON_PA
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2007 JAN 1 00:00:00
      State representation      Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      3.59331861
      -6.41758189
 
   WGC cannot compute angular separation between the Moon-Earth direction
   vectors in the MOON_ME and MOON_PA frames.
 
   To compute the sub-Earth point on the Moon using a high accuracy PCK and
   the MOON_ME frame, specify/select the following inputs in the
   ``Sub-Observer Point'' calculation:
 
      Target                    MOON
      Reference frame           MOON_ME
      Observer                  EARTH
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Converged Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2007 JAN 1 00:00:00
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      3.61141894
      -6.43950142
 
   To compute the sub-Earth point on the Moon using a high accuracy PCK and
   the MOON_PA frame, specify/select the following inputs in the
   ``Sub-Observer Point'' calculation:
 
      Target                    MOON
      Reference frame           MOON_PA
      Observer                  EARTH
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Converged Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2007 JAN 1 00:00:00
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      3.59350886
      -6.41758182
 
   WGC cannot compute the distance between the sub-Earth points computed in
   the MOON_ME and MOON_PA frames.
 
 
Earth rotation (erotat)
 
   Use the ``SPICE Class - Binary PCK Lesson Kernels (Earth)'' kernel set
   appearing near the bottom of the ``Kernel selection:'' menu to do this
   step in this lesson.
 
   To compute the Earth-Moon direction using a low accuracy PCK and the
   IAU_EARTH frame, specify/select the following inputs in the ``State
   Vector'' calculation:
 
      Target type               Object
      Target                    MOON
      Observer type             Object
      Observer                  EARTH
      Reference frame           IAU_EARTH
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2007 JAN 1 00:00:00
      State representation      Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      -35.49627162
      26.41695855
 
   To compute the Earth-Moon direction using a high accuracy PCK and the
   ITRF93 frame, specify/select the following inputs in the ``State
   Vector'' calculation:
 
      Target type               Object
      Target                    MOON
      Observer type             Object
      Observer                  EARTH
      Reference frame           ITRF93
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2007 JAN 1 00:00:00
      State representation      Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      -35.55428578
      26.41915557
 
   WGC cannot compute the separation angle between the Earth-Moon vectors
   in IAU_EARTH and ITRF93 frames.
 
   WGC cannot compute the IAU_EARTH and ITRF93 +X and +Z axis separation
   angles.
 
   To compute the DSS-13-Moon azimuth and elevation using a high accuracy
   PCK and the DSS-13_TOPO frame, specify/select the following inputs in
   the ``State Vector'' calculation:
 
      Target type               Object
      Target                    MOON
      Observer type             Object
      Observer                  DSS-13
      Reference frame           DSS-13_TOPO
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2007 JAN 1 00:00:00
      State representation      Planetocentric
 
   WGC will return the following longitude and latitude, deg, that are
   equivalent to the azimuth (AZ=-LON) and elevation (EL=LAT):
 
      -72.16900637
      20.68948821
 
   To compute the sub-solar point on Earth using a low accuracy PCK and the
   IAU_EARTH frame, specify/select the following inputs in the ``Sub-Solar
   Point'' calculation:
 
      Target                    EARTH
      Reference frame           IAU_EARTH
      Observer                  SUN
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2007 JAN 1 00:00:00
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      -177.10053149
      -22.91037699
 
   To compute the sub-solar point on Earth using a high accuracy PCK and
   the ITRF93 frame, specify/select the following inputs in the ``Sub-Solar
   Point'' calculation:
 
      Target                    EARTH
      Reference frame           ITRF93
      Observer                  SUN
      Sub-point type            Near point: ellipsoid
      Light propagation         To observer
      Light-time algorithm      Newtonian
      Stellar aberration        Corrected for stellar aberration
      Time system               UTC
      Time format               Calendar date and time
      Input time                2007 JAN 1 00:00:00
      Position representation   Planetocentric
 
   WGC will return the following longitude and latitude, deg:
 
      -177.15787351
      -22.91259307
 
   WGC cannot compute the distance between the sub-solar points computed in
   the IAU_EARTH and ITRF93 frames.
 
