Mars Reconnaissance Orbiter Primary/Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu Feb 12 15:42:33 PST 2009 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 Primary/Extended Science Phase of the MRO mission (orbits 10223 through 11403): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2008 OCT 01 00:01:05.182 2009 JAN 01 01:01:06.183 Status -------------------------------------------------------- This file was created by merging regular reconstructed OD solution SPK files produced by the MRO NAV team during the Primary/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_rec10395_10293_10395_r-v1.bsp spk_psp_rec10477_10393_10477_r-v1.bsp spk_psp_rec10563_10476_10563_r-v1.bsp spk_psp_rec10656_10562_10656_r-v1.bsp spk_psp_rec10731_10655_10731_r-v1.bsp spk_psp_rec10846_10730_10846_r-v1.bsp spk_psp_rec10906_10844_10906_r-v1.bsp spk_psp_rec10953_10906_10953_r-v1.bsp spk_psp_rec11055_10951_11055_r-v1.bsp spk_psp_rec11184_11016_11184_r-v1.bsp spk_psp_rec11290_11183_11290_r-v1.bsp spk_psp_rec11379_11289_11379_r-v1.bsp spk_psp_rec11475_11376_11475_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_psp9.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 10234 2008-10-01T22:09:54.817 -0.001 0.000 0.001 10251 2008-10-03T05:56:54.817 -0.000 -0.000 0.000 10271 2008-10-04T19:17:54.817 0.002 0.000 -0.001 10293 2008-10-06T12:28:54.817 0.001 0.000 -0.000 10318 2008-10-08T11:16:54.817 -0.002 0.000 0.001 10336 2008-10-09T21:36:54.817 0.003 0.000 0.001 10357 2008-10-11T11:58:54.817 -0.000 0.000 0.000 10375 2008-10-12T21:43:54.817 0.001 0.000 -0.000 10393 2008-10-14T07:28:54.817 -0.001 -0.000 0.001 10415 2008-10-16T00:38:54.817 0.002 -0.000 -0.001 10438 2008-10-17T19:27:54.817 0.001 0.000 -0.000 10459 2008-10-19T10:48:54.817 -0.002 0.000 0.001 10476 2008-10-20T18:43:54.817 0.002 -0.000 -0.001 10498 2008-10-22T11:38:54.817 -0.001 -0.000 0.000 10517 2008-10-24T00:03:54.817 -0.000 0.000 0.000 10540 2008-10-25T18:13:54.817 -0.001 0.000 0.000 10562 2008-10-27T11:33:54.817 -0.000 -0.000 0.000 10574 2008-10-28T09:48:54.817 0.000 0.000 0.000 10593 2008-10-29T21:28:54.817 -0.001 -0.000 0.001 10613 2008-10-31T10:38:54.817 0.001 -0.000 -0.000 10632 2008-11-01T22:23:54.817 0.002 0.000 -0.001 10655 2008-11-03T17:18:54.817 0.003 0.000 -0.001 10676 2008-11-05T09:10:54.817 -0.002 -0.000 0.000 10691 2008-11-06T12:44:54.817 0.006 -0.000 -0.003 10708 2008-11-07T20:32:54.817 -0.004 -0.000 0.002 10730 2008-11-09T13:40:54.817 0.002 0.000 -0.001 10750 2008-11-11T02:53:54.817 0.003 0.000 -0.001 10772 2008-11-12T19:53:54.817 0.003 0.000 0.000 10790 2008-11-14T05:28:54.817 -0.003 0.000 -0.001 10811 2008-11-15T22:28:54.817 0.000 -0.000 0.000 10833 2008-11-17T14:03:54.817 0.002 -0.000 -0.000 10844 2008-11-18T10:47:54.817 -0.002 -0.000 0.001 10863 2008-11-19T22:19:54.817 -0.002 0.000 0.001 10883 2008-11-21T11:43:54.817 -0.003 0.000 0.001 10906 2008-11-23T06:46:54.817 -0.003 -0.000 0.001 10924 2008-11-24T16:23:54.817 -0.001 0.000 0.000 10937 2008-11-25T16:58:54.817 0.001 -0.000 -0.000 10951 2008-11-26T19:08:54.817 0.000 -0.001 -0.000 10966 2008-11-27T22:58:54.816 0.004 0.002 -0.001 10977 2008-11-28T20:58:54.816 0.004 -0.001 0.000 11004 2008-11-30T21:58:54.816 -0.017 -0.001 0.009 11016 2008-12-01T20:28:54.816 0.020 0.002 -0.009 11106 2008-12-08T20:43:54.816 -0.017 -0.002 0.003 11129 2008-12-10T15:43:54.816 -0.001 -0.000 0.000 11145 2008-12-11T21:42:54.816 -0.004 -0.000 0.001 11161 2008-12-13T03:37:54.816 0.000 -0.000 -0.000 11183 2008-12-14T20:46:54.816 -0.002 0.000 0.001 11208 2008-12-16T19:31:54.816 0.001 0.000 -0.001 11225 2008-12-18T03:22:54.816 -0.002 0.000 0.002 11249 2008-12-20T00:50:54.816 0.004 0.000 0.000 11267 2008-12-21T09:51:54.816 0.000 0.000 -0.000 11289 2008-12-23T02:58:54.816 0.001 -0.000 -0.000 11310 2008-12-24T18:13:54.816 0.001 -0.000 -0.001 11336 2008-12-26T18:48:54.816 -0.001 0.000 0.000 11354 2008-12-28T04:38:54.816 -0.003 0.000 0.003 11366 2008-12-29T02:58:54.816 0.003 0.000 -0.002 11376 2008-12-29T21:38:54.816 0.003 -0.000 -0.002 11391 2008-12-31T01:41:54.816 0.001 0.000 -0.000