 
 
Cassini Spacecraft Orientation Reconstructed CK File
===========================================================================
 
     Comments added by Boris Semenov, NAIF/JPL, Mon Jun 25 12:14:59 PDT 2007
 
 
Orientation Data in the File
--------------------------------------------------------
 
     This file contains reconstructed orientation and angular velocity
     data for the Cassini Orbiter spacecraft frame, 'CASSINI_SC_COORD',
     relative to the 'J2000' inertial frame. The NAIF ID code for the
     'CASSINI_SC_COORD' frame is -82000.
 
 
Status
--------------------------------------------------------
 
     The data in this file were created by the Cassini Project for
     archiving with the Planetary Data System (PDS).
 
 
Pedigree
--------------------------------------------------------
 
     Reconstructed CK files were delivered to the Cassini Project by the
     Attitude and Articulation Subsystem (AACS). These reconstructed
     files contain spacecraft orientation and angular rates returned
     in Cassini spacecraft telemetry.  The data were packaged by AACS
     using the SPICE utility MSOPCK provided by NAIF.  Later files
     were created by accessing the MSOPCK software through the AACS
     C-Kernel Generation Tool (ACKT) user interface.
 
     Files generated prior to January 2004 have been merged to remove
     redundant data and in some cases provide longer interpolation
     intervals since the spacecraft was primarily earth pointed during
     that time.
 
Approximate Time Coverage
--------------------------------------------------------
 
     This file covers the following interval of the mission:
 
          Coverage Begin UTC       Coverage End UTC
          ------------------------ ------------------------
          2006-SEP-29 00:00:00.468 2006-OCT-03 23:59:57.711
 
     This file is a type 3 CK file which allows linear interpolation
     between orientation data points extracted from telemetry. Such
     interpolation is not applicable to the whole file but only inside
     intervals where enough orientation telemetry data are available
     and orientation data points were close enough to each other in time
     for such interpolation to make sense.
 
     The nominal quaternion time spacing in the telemetry stream is
     4 seconds but a spacing as large as 16 seconds may exist between
     adjacent data points.
 
     A table containing the complete list of valid interpolation intervals
     in the file is provided in Appendix 2.
 
Related Information
--------------------------------------------------------
 
     AACS has carried out comparisons between some predicted CK
     files and the corresponding reconstructed CK files. Numerical
     values for comparison statistics as well as interval and gap
     start and stop times have been added to the original comment
     areas (Appendix 1, below) of those CK files for which comparisons
     exist. For more information about these comparisons, see the file
     "extras/ckxtra/cknav/navinfo.txt" in this volume.
 
Usage Note
--------------------------------------------------------
 
     In order to use this file, a Cassini spacecraft clock coefficients
     (SCLK) file containing coefficients mapping on-board time to ET must
     be loaded into a user's program. The latest available SCLK file
     should be used. In addition, the current leapseconds file must be
     loaded into a user's program.
 
 
Contacts
--------------------------------------------------------
 
     If you have any questions regarding this data contact:
 
        Adrian W. Tinio  (818)-354-7511 Adrian.W.Tinio@jpl.nasa.gov
 
        Boris V. Semenov (818)-354-8136 Boris.Semenov@jpl.nasa.gov
 
 
Appendix 1: Comments from the original file
--------------------------------------------------------
 
 
********************************************************************************
 
Cassini Reconstruction C-Kernel
Type 3 C-Kernel with rate data
Generated by burkt
 
********************************************************************************
MSOPCK SETUP FILE: /aacs/ckernels/ACKTtmpDir/ckernel.setup
********************************************************************************
 
\begindata
  LSK_FILE_NAME = '/afs/jpl/group/casops/dom/data/main/ls_kernel/naif0008.tls'
  SCLK_FILE_NAME = '/afs/jpl/group/casops/dom/data/main/sclk_kernel/cas00101.tsc'
  INTERNAL_FILE_NAME = 'ckernel.file'
  COMMENTS_FILE_NAME = '/aacs/ckernels/ACKTtmpDir/ckernel.comments'
  CK_TYPE = 3
  CK_SEGMENT_ID = 'TELEMETRY CASSINI S/C ATTITUDE'
  INSTRUMENT_ID =  -82000
  REFERENCE_FRAME_NAME = 'J2000'
  ANGULAR_RATE_PRESENT = 'YES'
  QUATERNION_NORM_ERROR = 1.0e-3
  ANGULAR_RATE_THRESHOLD = ( 0.01745329, 0.01745329, 0.01745329 )
  MAXIMUM_VALID_INTERVAL = 16
  INPUT_TIME_TYPE = 'SCLK'
  INPUT_DATA_TYPE = 'MSOP QUATERNIONS'
  ANGULAR_RATE_FRAME = 'INSTRUMENT'
  PRODUCER_ID = 'Cassini AACS Operations'
\begintext
 
********************************************************************************
RUN-TIME OBTAINED META INFORMATION:
********************************************************************************
 
PRODUCT_CREATION_TIME = 2006-10-07T02:42:36
START_TIME            = 2006-09-29T00:00:00.468
STOP_TIME             = 2006-10-03T23:59:57.711
 
********************************************************************************
INTERPOLATION INTERVALS IN THE FILE SEGMENTS:
********************************************************************************
 
SEG.SUMMARY: ID -82000, COVERG: 2006-09-29T00:00:00.468 2006-10-03T14:22:17.683
--------------------------------------------------------------------------------
      2006-09-29T00:00:00.468    2006-09-30T19:37:55.466
      2006-09-30T19:38:15.216    2006-10-03T14:22:17.683
 
SEG.SUMMARY: ID -82000, COVERG: 2006-10-03T14:22:17.683 2006-10-03T23:59:57.711
--------------------------------------------------------------------------------
      2006-10-03T14:22:17.683    2006-10-03T19:37:53.812
      2006-10-03T19:38:13.562    2006-10-03T19:38:41.561
      2006-10-03T19:40:13.811    2006-10-03T21:57:37.758
      2006-10-03T22:00:37.757    2006-10-03T23:59:57.711
 
 
********************************************************************************
 
AACS C-Kernel Comparison
 
 
Spice Version: CSPICE_N0058
 
 
First CK (RECON): /afs/jpl/group/casops/dom/data/main2/sco_bc_kernel/06272_06277ra.bc
 
PRODUCT_CREATION_TIME = 2006-280T02:42:36
QUERY_START_TIME      = 2006-272T00:00:00
QUERY_STOP_TIME       = 2006-276T23:59:57
INTERVALS             = 6
 
Interval Start (SCET)   Interval End (SCET)     Interval Duration
---------------------   ---------------------   Gap Duration
                                                HH:MM:SEC
                                                -----------------
2006-272T00:00:00.468   2006-273T19:37:55.466   43:37:54.998
                                                 0:00:19.750
2006-273T19:38:15.216   2006-276T14:22:17.683   66:44:02.467
                                                 0:00:00.000
2006-276T14:22:17.683   2006-276T19:37:53.812    5:15:36.129
                                                 0:00:19.750
2006-276T19:38:13.562   2006-276T19:38:41.561    0:00:27.999
                                                 0:01:32.250
2006-276T19:40:13.811   2006-276T21:57:37.758    2:17:23.947
                                                 0:02:59.999
2006-276T22:00:37.757   2006-276T23:59:57.711    1:59:19.954
 
 
Gap Start (SCET)        Gap End (SCET)          Gap Duration
---------------------   ---------------------   HH:MM:SEC
                                                ------------
2006-273T19:37:55.466   2006-273T19:38:15.216    0:00:19.750
2006-276T14:22:17.683   2006-276T14:22:17.683    0:00:00.000
2006-276T19:37:53.812   2006-276T19:38:13.562    0:00:19.750
2006-276T19:38:41.561   2006-276T19:40:13.811    0:01:32.250
2006-276T21:57:37.758   2006-276T22:00:37.757    0:02:59.999
 
 
Second CK (KPT): /afs/jpl/group/casops/dom/data/main2/sco_bc_kernel/06263_06295pc_psiv2.bc
 
PRODUCT_CREATION_TIME = 2006-236T23:05:39
QUERY_START_TIME      = 2006-263T20:22:00
QUERY_STOP_TIME       = 2006-295T18:26:00
INTERVALS             = 1
 
Interval Start (SCET)   Interval End (SCET)     Interval Duration
---------------------   ---------------------   Gap Duration
                                                HH:MM:SEC
                                                -----------------
2006-263T20:22:00.000   2006-295T18:26:00.000  766:04:00.000
 
 
Gap Start (SCET)        Gap End (SCET)          Gap Duration
---------------------   ---------------------   HH:MM:SEC
                                                ------------
 
 
Day No 1  (DOY 272-273)
2006-272T00:00:00.468 to 2006-273T00:00:00.468
Maximum Error
X  0.56 mrad  at  2006-272T10:20:50.468
Y  1.30 mrad  at  2006-272T10:27:20.468
Z  2.31 mrad  at  2006-272T11:25:15.468
 
Mean Error        1-Sigma Deviation
X  0.02 mrad      X  0.034 mrad
Y  0.05 mrad      Y  0.172 mrad
Z  0.67 mrad      Z  0.890 mrad
 
 
Day No 2  (DOY 273-274)
2006-273T00:00:00.468 to 2006-274T00:00:00.468
Maximum Error
X  1.42 mrad  at  2006-273T20:26:10.468
Y  1.16 mrad  at  2006-273T20:10:50.468
Z  2.08 mrad  at  2006-273T20:10:35.468
 
Mean Error        1-Sigma Deviation
X  0.22 mrad      X  0.467 mrad
Y  0.14 mrad      Y  0.273 mrad
Z  0.12 mrad      Z  0.191 mrad
 
 
Day No 3  (DOY 274-275)
2006-274T00:00:00.468 to 2006-275T00:00:00.468
Maximum Error
X  1.27 mrad  at  2006-274T00:00:00.468
Y  1.53 mrad  at  2006-274T02:42:35.468
Z  2.55 mrad  at  2006-274T03:37:40.468
 
Mean Error        1-Sigma Deviation
X  0.16 mrad      X  0.336 mrad
Y  0.12 mrad      Y  0.252 mrad
Z  0.55 mrad      Z  0.957 mrad
 
 
Day No 4  (DOY 275-276)
2006-275T00:00:00.468 to 2006-276T00:00:00.468
Maximum Error
X  0.43 mrad  at  2006-275T19:45:05.468
Y  1.63 mrad  at  2006-275T19:42:25.468
Z  1.05 mrad  at  2006-275T18:56:45.468
 
Mean Error        1-Sigma Deviation
X  0.07 mrad      X  0.091 mrad
Y  0.06 mrad      Y  0.145 mrad
Z  0.23 mrad      Z  0.325 mrad
 
 
Day No 5  (DOY 276-276)
2006-276T00:00:00.468 to 2006-276T23:59:57.711
Maximum Error
X  0.97 mrad  at  2006-276T03:56:20.468
Y  0.94 mrad  at  2006-276T10:19:30.468
Z  1.87 mrad  at  2006-276T03:48:00.468
 
Mean Error        1-Sigma Deviation
X  0.20 mrad      X  0.333 mrad
Y  0.13 mrad      Y  0.202 mrad
Z  0.39 mrad      Z  0.526 mrad
 
 
Appendix 2: Interpolation Intervals in the File
--------------------------------------------------------
 
     The information in this section has been generated by running the SPICE
     CKBRIEF utility program using -dump -utc command line options.
 
 
CKBRIEF Version: 3.2.0, 2006-11-02. SPICE Toolkit Version: N0061.
 
 
Summary for: data/ck/06272_06277ra.bc
 
Segment No.: 1
 
Object:  -82000
  Interval Begin UTC       Interval End UTC         AV
  ------------------------ ------------------------ ---
  2006-SEP-29 00:00:00.468 2006-SEP-30 19:37:55.466 Y
  2006-SEP-30 19:38:15.216 2006-OCT-03 14:22:17.683 Y
 
Segment No.: 2
 
Object:  -82000
  Interval Begin UTC       Interval End UTC         AV
  ------------------------ ------------------------ ---
  2006-OCT-03 14:22:17.683 2006-OCT-03 19:37:53.812 Y
  2006-OCT-03 19:38:13.562 2006-OCT-03 19:38:41.561 Y
  2006-OCT-03 19:40:13.811 2006-OCT-03 21:57:37.758 Y
  2006-OCT-03 22:00:37.757 2006-OCT-03 23:59:57.711 Y
 
 
