 
 
Deep Space 1 SPK file, Complete Mission, DS1 Radio NAV Solution
===========================================================================
 
     Created by Brian Kennedy, DS1 Radio NAV, January 2002
 
     Documented by Boris Semenov, NAIF/JPL, October 1, 2003
 
 
Objects in the Ephemeris
--------------------------------------------------------
 
     This file contains ephemeris data for Deep Space 1 (DS1) spacecraft.
     NAIF ID code for DS1 is -30.
 
 
Approximate Time Coverage
--------------------------------------------------------
 
     This file covers the whole DS1 mission:
 
        COVERAGE BEGIN TIME (TDB):   1998 OCT 24 18:00:00.000
        COVERAGE END TIME (TDB):     2003 DEC 31 00:00:00.000
 
 
Status
--------------------------------------------------------
 
     This file was created by merging regular radio-NAV OD SPK files
     produced during the mission for archiving with the Planetary Data
     System (PDS).
 
 
Pedigree
--------------------------------------------------------
 
     The original regular radio-NAV OD solution SPK files were created and
     delivered to the DS1 project data base (AFS) by the DS1 Radio NAV
     Team. At the end of the mission the Radio NAV team identified a subset
     of the files containing the best trajectory and providing complete
     coverage for the whole mission (plus extrapolated coverage a year
     ahead, till the end of 2003) and merged them together. The merged file
     was released to the project under name ``spk.merged.bsp'' in January
     2002.
 
 
Segment Boundary Discontinuities
--------------------------------------------------------
 
     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 Appendix 1 of these comments.
 
 
Usage
--------------------------------------------------------
 
     This file should be used together with DE405 planetary ephemeris since
     the trajectory in the original SPK files was determined based on that
     ephemeris.
 
 
Contacts
--------------------------------------------------------
 
     If you have questions regarding this data contact
 
        Boris V. Semenov
        (818)-354-8136
        Boris.Semenov@jpl.nasa.gov
 
     or DS1 Radio NAV Team:
 
        Brian M. Kennedy
        (818)-354-6327
        Brian.M.Kennedy@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 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 contains the UTC
     time of that segment boundary. 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 ds1_radionav.bsp:
        #
        #  BOUNDARY TIME (UTC)     DOWNTRK       INPLANE       NORMAL
        #----------------------- ------------- ------------- -------------
        1998-11-18T23:58:56.817        -0.127         0.238        -0.371
        1998-12-04T23:58:56.816         3.065        -1.683        -4.887
        1999-01-05T15:58:55.815     -3430.169     -5386.848      3327.291
        1999-03-08T13:58:55.814         6.776         4.711         0.009
        1999-05-29T00:58:55.815       -93.354       559.855      -407.233
        1999-06-19T23:58:55.815        10.119        11.316       -48.110
        1999-07-13T22:28:55.816         1.042         1.247        23.805
        1999-07-24T03:28:55.816       -27.607       -31.636        69.916
        1999-07-29T07:58:55.816       165.395       149.833      -618.676
        1999-09-06T15:58:55.817     -1433.378    -10130.434    -10565.715
        1999-10-21T23:58:55.817    -36458.812    -25059.595      -957.809
        2000-06-18T23:58:55.815       992.140     -7873.347     13313.146
        2000-07-18T17:58:55.816     -1077.352      -210.022      8964.160
        2000-08-20T23:58:55.817      4120.866       403.422     -7790.437
        2000-11-28T17:28:55.816       214.296       -10.109      -691.245
        2001-03-16T23:58:55.814     -1082.403       327.055      -388.787
        2001-05-29T11:58:55.815       443.202      -565.627     -3861.860
        2001-07-24T23:58:55.816       -20.770        16.247      -122.806
        2001-07-30T19:58:55.816      -382.101       311.303       -69.663
        2001-08-29T09:58:55.817       187.150      -171.734       -48.809
        2001-09-22T23:58:55.817        -9.324         9.325        89.774
        2001-10-30T10:58:55.817       135.428      -147.819      -809.967
 
 
