 
 
MER1 Cruise SPK file, Final MER NAV Solution
===========================================================================
 
     Created by MER NAV on March 24, 2004; documented by Boris Semenov,
     NAIF/JPL, July 7, 2004
 
 
Objects in the Ephemeris
--------------------------------------------------------
 
     This file contains ephemeris data for Mars Exploration Rover 1 (MER1)
     spacecraft. NAIF ID code for MER1 is -253.
 
     This file also contains a portion of the DE410 planet ephemerides
     covering the same period of time.
 
 
Approximate Time Coverage
--------------------------------------------------------
 
     This file covers the MER1 cruise phase, up to the atmospheric entry:
 
        COVERAGE BEGIN TIME (TDB):   2003 JUL 08 04:37:02.184
        COVERAGE END TIME (TDB):     2004 JAN 25 04:49:45.905
 
 
Status
--------------------------------------------------------
 
     This file is the final reconstructed cruise trajectory SPK created by
     MER NAV for archiving with the Planetary Data System (PDS). It was
     originally named spk_b_c_030708-040125_recon.bsp.
 
 
Contacts
--------------------------------------------------------
 
     If you have questions regarding this data contact
 
        Boris V. Semenov
        (818)-354-8136
        bsemenov@spice.jpl.nasa.gov
 
     or MER NAV Team Lead:
 
        Louis A. D'Amario
        (818)-354-3209
        Louis.A.Damario@jpl.nasa.gov
 
 
Appendix 1: Segment Boundary Discontinuity Summary
--------------------------------------------------------
 
     This SPK file contains a large number of SPK segments that came from
     original individual SPK files. Although, each segment provides
     continuous trajectory within the interval that it covers, in general a
     position and velocity discontinuity exists at the boundary of the
     segment and the segments whose coverage immediately precede and follow
     it. The times and magnitudes of these discontinuities are provided in
     the table included in this Appendix.
 
     The top portion of the table contains the original name of this SPK
     file. All descriptive lines in the top portion of the file start with
     the ``#'' character to allow direct plotting of the data in the
     freeware ``gnuplot'' application.
 
     The table consists of 4 columns. The first column is the UTC time when
     a segment boundary with discontinuity occurs. The last three columns
     (2..4) contain view coordinate frame components -- ``down track''
     (this direction is parallel to the velocity vector), ``normal to
     plane'' (this direction is computed as cross product of position
     vector by velocity vector) and ``in plane'' (this direction is
     computed as a cross product of ``down track'' by ``normal to plane'')
     -- of the difference between the state vectors computed at that UTC
     time defining segment boundary at which a discontinuity exists.
 
     The pairs of segments and discontinuity times are determined using an
     algorithm that emulates the standard SPK loading priority -- ``last
     loaded segment takes precedence''. Therefore, the discontinuities
     summarized in the file are those which a user reading file would
     actually see.
 
     The difference components in the view coordinate frame were computed
     for each discontinuity using the following algorithm:
 
         --   A single state was computed from each pair of segment the
              J2000 frame at the time of discontinuity.
 
         --   For this pair of states, a position difference vector was
              computed by subtracting the state computed from the segment
              with higher priority from the state computed from segment
              with lower priority. Then, a frame transformation matrix
              rotating these difference vectors from J2000 to the view
              coordinate frame defined by the state obtained from the
              higher priority segment was computed, and the position
              difference vector was rotated to the view frame coordinates
              using this matrix.
 
     The segment boundary discontinuities for this file are:
 
        #
        # Summary of discontinuities at segment boundaries for
        # SPK file spk_b_c_030708-040125_recon.bsp:
        #
        #  BOUNDARY TIME (UTC)   DOWNTRK INPLANE  NORMAL
        #----------------------- ------- ------- -------
        2003-07-18T20:58:55.816  -0.052   0.072  -0.147
        2003-08-13T02:58:55.817  -0.019   0.003   0.042
        2003-10-03T09:13:55.817   0.187   0.062  -0.107
        2003-10-20T15:58:55.817  -0.086  -0.047   0.302
        2003-12-03T02:58:55.816   0.003   0.001   0.087
 
 
Appendix 2: Original Comments
--------------------------------------------------------
 
     This appendix contains original contents of the comment area of this
     SPK file, including:
 
         --   NIOSPK log
 
         --   contents of the LSK file used in NIOSPK run
 
         --   SPK file release form
 
 
NIOSPK log
 
        ; spk_b_teco030708-entry040125_recon.bsp LOG FILE
        ;
        ; Created 2004-03-19/19:33:29.00.
        ;
        ; BEGIN NIOSPK COMMANDS
 
        LEAPSECONDS_FILE    = /msop/nav/naif/dat/naif0007.tls
        SPK_FILE            = spk_b_teco030708-entry040125_recon.bsp
          SPK_LOG_FILE      = spk_b_teco030708-entry040125_recon.cmd.log
          INCLUDE_TEXT_FILE = /msop/nav/naif/dat/naif0007.tls
          SOURCE_NIO_FILE   = p_b_c_teco-od04.nio
            BEGIN_TIME      = CAL-ET 2003 JUL 08 04:37:02.184
            END_TIME        = CAL-ET 2003 JUL 08 05:05:00.000
          SOURCE_NIO_FILE   = p_b_c_030708-040131_od04.nio
            BEGIN_TIME      = CAL-ET 2003 JUL 08 05:05:00.000
            END_TIME        = CAL-ET 2003 JUL 09 19:40:01.000
          SOURCE_NIO_FILE   = p_b_c_030709-040127_od06.nio
            BEGIN_TIME      = CAL-ET 2003 JUL 09 19:40:00.000
            END_TIME        = CAL-ET 2003 JUL 18 21:00:01.000
          SOURCE_NIO_FILE   = p_b_c_030718-040127_od11.nio
            BEGIN_TIME      = CAL-ET 2003 JUL 18 21:00:00.000
            END_TIME        = CAL-ET 2003 AUG 13 03:00:01.000
          SOURCE_NIO_FILE   = p_b_c_030813-040126_od13.nio
            BEGIN_TIME      = CAL-ET 2003 AUG 13 03:00:00.000
            END_TIME        = CAL-ET 2003 OCT 03 09:15:01.000
          SOURCE_NIO_FILE   = p_b_c_031003-040126_od18.nio
            BEGIN_TIME      = CAL-ET 2003 OCT 03 09:15:00.000
            END_TIME        = CAL-ET 2003 OCT 20 16:00:01.000
          SOURCE_NIO_FILE   = p_b_c_031020-040126_od30.nio
            BEGIN_TIME      = CAL-ET 2003 OCT 20 16:00:00.000
            END_TIME        = CAL-ET 2003 DEC 03 03:00:01.000
          SOURCE_NIO_FILE   = p_b_c_031203-040126_od41.nio
            BEGIN_TIME      = CAL-ET 2003 DEC 03 03:00:00.000
            END_TIME        = CAL-ET 2004 JAN 25 04:49:45.905
          SOURCE_NIO_FILE   = /msop/nav/common/eph/nio/de410_1992-2019.nio
            BEGIN_TIME      = CAL-ET 2003 JUL 08 04:37:02.184
            END_TIME        = CAL-ET 2004 JAN 25 04:49:45.905
 
        ; END NIOSPK COMMANDS
 
 
Contents of the LSK file used in NIOSPK run
 
        LEAPSECONDS KERNEL FILE
        ===================================================================
 
        Modifications:
        --------------
        1998, Jul  17   WLT  Modified file to account for the leapsecond
                             that will occur on December 31, 1998.
 
        1997, Feb  22   WLT  Modified file to account for the leapsecond
                             that will occur on June 30, 1997.
 
        1995, Dec  14   KSZ  Corrected date of last leapsecond from 1-1-95
                             to 1-1-96.
 
        1995, Oct  25   WLT  Modified file to account for the leapsecond
                             that will occur on Dec 31, 1995.
 
        1994, Jun  16   WLT  Modified file to account for the leapsecond on
                             June 30, 1994.
 
        1993, Feb. 22  CHA   Modified file to account for the leapsecond on
                             June 30, 1993.
 
        1992, Mar. 6   HAN   Modified file to account for the leapsecond on
                             June 30, 1992.
 
        1990, Oct. 8   HAN   Modified file to account for the leapsecond on
                             Dec. 31, 1990.
 
 
        Explanation:
        ------------
 
        The contents of this file are used by the routine DELTET to
        compute the time difference
 
        [1]       DELTA_ET  =  ET - UTC
 
        the increment to be applied to UTC to give ET.
 
        The difference between UTC and TAI,
 
        [2]       DELTA_AT  =  TAI - UTC
 
        is always an integral number of seconds. The value of DELTA_AT
        was 10 seconds in January 1972, and increases by one each time
        a leap second is declared. Combining [1] and [2] gives
 
        [3]       DELTA_ET  =  ET - (TAI - DELTA_AT)
 
                            =  (ET - TAI) + DELTA_AT
 
        The difference (ET - TAI) is periodic, and is given by
 
        [4]       ET - TAI  =  DELTA_T_A  + K sin E
 
        where DELTA_T_A and K are constant, and E is the eccentric anomaly
        of the heliocentric orbit of the Earth-Moon barycenter. Equation
        [4], which ignores small-period fluctuations, is accurate to about
        0.000030 seconds.
 
        The eccentric anomaly E is given by
 
        [5]       E = M + EB sin M
 
        where M is the mean anomaly, which in turn is given by
 
        [6]       M = M  +  M t
                       0     1
 
        where t is the number of ephemeris seconds past J2000.
 
        Thus, in order to compute DELTA_ET, the following items are
        necessary.
 
                  DELTA_TA
                  K
                  EB
                  M0
                  M1
                  DELTA_AT      after each leap second.
 
        The numbers, and the formulation, are taken from the following
        sources.
 
             1) Moyer, T.D., Transformation from Proper Time on Earth to
                Coordinate Time in Solar System Barycentric Space-Time
                Frame of Reference, Parts 1 and 2, Celestial Mechanics
                23 (1981), 33-56 and 57-68.
 
             2) Moyer, T.D., Effects of Conversion to the J2000
                Astronomical Reference System on Algorithms for Computing
                Time Differences and Clock Rates, JPL IOM 314.5--942, 1
                October 1985.
 
        The variable names used above are consistent with those used in the
        Astronomical Almanac.
 
        \begindata
 
        DELTET/DELTA_T_A       =   32.184
        DELTET/K               =    1.657D-3
        DELTET/EB              =    1.671D-2
        DELTET/M               = (  6.239996D0   1.99096871D-7 )
 
        DELTET/DELTA_AT        = ( 10,   @1972-JAN-1
                                   11,   @1972-JUL-1
                                   12,   @1973-JAN-1
                                   13,   @1974-JAN-1
                                   14,   @1975-JAN-1
                                   15,   @1976-JAN-1
                                   16,   @1977-JAN-1
                                   17,   @1978-JAN-1
                                   18,   @1979-JAN-1
                                   19,   @1980-JAN-1
                                   20,   @1981-JUL-1
                                   21,   @1982-JUL-1
                                   22,   @1983-JUL-1
                                   23,   @1985-JUL-1
                                   24,   @1988-JAN-1
                                   25,   @1990-JAN-1
                                   26,   @1991-JAN-1
                                   27,   @1992-JUL-1
                                   28,   @1993-JUL-1
                                   29,   @1994-JUL-1
                                   30,   @1996-JAN-1
                                   31,   @1997-JUL-1
                                   32,   @1999-JAN-1 )
 
 
 
SPK file release form
 
        MER NAVIGATION TEAM
        FILE RELEASE
 
 
        Mission Name:           MARS_EXPLORATION_ROVER_B
        Spacecraft Name:        MARS_EXPLORATION_ROVER_1
        Spacecraft ID:          253
 
        Release to:             MPT, IST, SRET, SOST, DSN_PREDICTS,
                                MDOT/NAIF, MDOT
        Date/Time:              03/24/2004 14:00 PST
 
        Type of File:           SPICE Spacecraft and Planet Ephemeris
                                Kernel (SPK) File
 
        Computer:               mmdom
        Directory:              /domops/data/mer/253/main/spk_kernel
 
        File Name:              spk_b_c_030708-040125_recon.xsp.sfdu
 
        Start Time:             08-JUL-2003 04:37:02.205 ET
        End Time:               25-JAN-2004 04:49:45.884 ET
 
        Planetary Ephemeris:    DE-410
 
        Comments:
        This binary SPK file is being released in support NAIF SPICE data
        for archival in the Planetary Data System (PDS).
 
        This is a reconstructed cruise trajectory for MER-B, beginning at
        TECO and ending at atmospheric entry, based upon the following 7
        OD solutions that have been merged together:
 
        Note: The TECO epoch state was produced via backwards propagation
        from OD04.
        p_b_c_030708-040131_od04.nio
        p_b_c_030709-040127_od06.nio
        p_b_c_030718-040127_od11.nio
        p_b_c_030813-040126_od13.nio
        p_b_c_031003-040126_od18.nio
        p_b_c_031020-040126_od30.nio
        p_b_c_031203-040126_od41.nio
 
 
        Released by:            Lynn Craig
                                MER NAV
 
        Approved:               Louis D'Amario
                                MER NAV Team Chief
 
 
