Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Fri May 21 09:39:53 PDT 2010 Objects in the Ephemeris -------------------------------------------------------- This SPK file contains ephemeris data for the Mars Reconnaissance Orbiter (MRO) spacecraft. The NAIF ID code for MRO is -74. Approximate Time Coverage -------------------------------------------------------- This file covers the following part of the Extended Science Phase of the MRO mission (orbits 16088 through 17242): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2010 JAN 01 00:01:06.183 2010 APR 01 01:01:06.185 Status -------------------------------------------------------- This file was created by merging regular reconstructed OD solution SPK files produced by the MRO NAV team during the Extended Science Phase of the mission. This file was created by NAIF for archiving in the Planetary Data System (PDS). Pedigree -------------------------------------------------------- The original SPK files used to create this file contained only reconstructed trajectory. They were officially delivered to the MRO project data base by the MRO NAV team. The list of the original files data from which has been merged into this file is provided in Appendix 1 of these comments. 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 coverages immediately precede or follow it. The times and magnitudes of these discontinuities are provided in Appendix 2 of these comments. Usage -------------------------------------------------------- This file should be used together with DE414 planetary ephemeris and MAR063 satellite ephemeris since the original SPK files contained subsets of these particular ephemeris in them. Contacts -------------------------------------------------------- If you have questions regarding this data contact Boris V. Semenov (818)-354-8136 Boris.Semenov@jpl.nasa.gov Appendix 1: Original SPK List -------------------------------------------------------- The original SPK files, the data from which has been included into this file, are: spk_psp_rec16145_16009_16145_r-v1.bsp spk_psp_rec16234_16144_16234_r-v1.bsp spk_psp_rec16313_16233_16313_r-v1.bsp spk_psp_rec16387_16312_16387_r-v1.bsp spk_psp_rec16494_16386_16494_r-v1.bsp spk_psp_rec16572_16493_16572_r-v1.bsp spk_psp_rec16663_16571_16663_r-v1.bsp spk_psp_rec16761_16660_16761_r-v1.bsp spk_psp_rec16861_16761_16861_r-v1.bsp spk_psp_rec16939_16851_16939_r-v1.bsp spk_psp_rec17012_16938_17012_r-v1.bsp spk_psp_rec17121_17010_17121_r-v1.bsp spk_psp_rec17203_17120_17203_r-v1.bsp spk_psp_rec17282_17202_17282_r-v1.bsp Appendix 2: 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 5 columns. The first column is the orbit number within which a segment boundary with discontinuity occurs. The next column contains the UTC time of that segment boundary. The last three columns (3..5) 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 ./mro_psp14.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 16089 2010-01-01T03:38:53.816 0.000 -0.000 -0.000 16110 2010-01-02T18:47:53.816 0.001 0.000 -0.001 16127 2010-01-04T02:38:53.815 -0.000 0.000 0.001 16144 2010-01-05T10:19:53.815 -0.000 -0.000 0.001 16163 2010-01-06T21:48:53.815 -0.000 -0.000 0.001 16183 2010-01-08T11:13:53.815 -0.000 -0.000 0.001 16202 2010-01-09T22:35:53.815 0.000 0.000 -0.000 16220 2010-01-11T08:15:53.815 0.001 0.000 -0.001 16233 2010-01-12T08:38:53.815 -0.000 -0.000 0.000 16252 2010-01-13T20:13:53.815 -0.000 -0.000 0.001 16271 2010-01-15T07:59:23.815 -0.001 -0.000 0.002 16288 2010-01-16T15:46:23.815 0.000 -0.000 -0.000 16312 2010-01-18T12:31:53.815 0.001 0.000 -0.001 16330 2010-01-19T22:11:53.815 -0.000 0.000 0.000 16353 2010-01-21T17:13:53.815 -0.000 0.000 0.001 16368 2010-01-22T21:15:53.815 0.001 -0.000 -0.001 16386 2010-01-24T06:38:53.815 0.000 -0.000 -0.000 16403 2010-01-25T14:38:53.815 -0.000 -0.000 0.000 16424 2010-01-27T05:48:53.815 -0.000 -0.000 0.000 16439 2010-01-28T10:07:53.815 0.000 0.000 -0.000 16457 2010-01-29T19:47:53.815 -0.000 -0.000 0.001 16475 2010-01-31T05:27:33.815 -0.000 -0.000 0.000 16493 2010-02-01T14:48:53.815 0.001 0.000 -0.001 16514 2010-02-03T06:08:53.815 0.001 -0.000 -0.000 16535 2010-02-04T21:28:53.815 -0.001 0.000 0.001 16553 2010-02-06T07:18:53.815 -0.000 0.000 0.000 16571 2010-02-07T17:28:53.815 -0.002 -0.000 -0.000 16593 2010-02-09T10:01:53.815 -0.000 -0.000 0.000 16609 2010-02-10T16:00:53.814 0.002 0.000 -0.001 16625 2010-02-11T21:57:23.814 -0.002 -0.000 0.001 16644 2010-02-13T09:29:03.814 0.000 -0.000 -0.000 16660 2010-02-14T15:08:53.814 0.003 0.000 -0.001 16682 2010-02-16T08:18:53.814 0.001 0.000 -0.001 16702 2010-02-17T22:18:53.814 -0.001 -0.000 0.000 16724 2010-02-19T14:58:53.814 0.001 0.000 -0.000 16743 2010-02-21T02:31:53.814 0.001 -0.000 -0.000 16761 2010-02-22T11:58:53.814 -0.000 -0.000 0.000 16784 2010-02-24T07:03:53.814 0.002 0.000 -0.001 16804 2010-02-25T20:23:53.814 0.001 0.000 -0.000 16823 2010-02-27T07:58:53.814 0.004 -0.000 -0.001 16841 2010-02-28T17:33:53.814 -0.000 -0.000 0.000 16851 2010-03-01T12:32:53.814 0.001 -0.000 -0.001 16868 2010-03-02T20:20:53.814 -0.001 -0.000 0.000 16885 2010-03-04T04:06:53.814 0.001 0.000 -0.000 16901 2010-03-05T10:03:53.814 -0.002 -0.000 0.001 16918 2010-03-06T17:43:53.814 -0.003 0.000 0.001 16938 2010-03-08T07:07:53.814 0.003 0.000 -0.001 16959 2010-03-09T22:06:53.814 -0.005 0.000 -0.001 16979 2010-03-11T11:31:53.814 0.008 0.000 0.001 16996 2010-03-12T19:19:53.814 0.003 0.000 0.000 17010 2010-03-13T21:44:53.814 -0.009 -0.000 0.002 17029 2010-03-15T09:03:53.814 -0.010 -0.000 -0.001 17044 2010-03-16T14:18:53.814 -0.003 0.000 -0.001 17062 2010-03-18T00:23:53.814 0.007 0.000 0.002 17082 2010-03-19T12:13:53.814 0.004 0.000 0.000 17101 2010-03-21T00:08:53.814 0.006 -0.000 -0.002 17120 2010-03-22T11:35:53.814 0.001 -0.000 -0.000 17139 2010-03-23T22:51:53.814 -0.004 -0.000 -0.000 17159 2010-03-25T12:22:53.814 0.005 0.000 -0.000 17176 2010-03-26T20:02:53.814 0.007 -0.000 0.000 17190 2010-03-27T22:14:53.814 0.007 0.000 0.001 17202 2010-03-28T20:43:53.814 -0.001 -0.000 -0.000 17222 2010-03-30T11:38:53.814 0.009 0.000 0.003 17242 2010-04-01T00:13:53.814 0.002 -0.000 -0.001