Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue May 21 14:40:01 PDT 2013 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 30153 through 31307): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2013 JAN 01 00:01:07.183 2013 APR 01 01:01:07.185 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_rec30222_30138_30222_r-v1.bsp spk_psp_rec30276_30221_30276_r-v1.bsp spk_psp_rec30367_30275_30367_r-v1.bsp spk_psp_rec30493_30365_30493_r-v1.bsp spk_psp_rec30562_30492_30562_r-v1.bsp spk_psp_rec30678_30562_30678_r-v1.bsp spk_psp_rec30762_30677_30762_r-v1.bsp spk_psp_rec30832_30761_30832_r-v1.bsp spk_psp_rec30945_30832_30945_r-v1.bsp spk_psp_rec31037_30943_31037_r-v1.bsp spk_psp_rec31127_31036_31127_r-v1.bsp spk_psp_rec31192_31125_31192_r-v1.bsp spk_psp_rec31285_31191_31285_r-v1.bsp spk_psp_rec31383_31285_31383_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_psp26.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 30157 2013-01-01T08:53:52.816 0.005 0.000 0.002 30170 2013-01-02T09:16:22.816 0.001 -0.000 0.000 30183 2013-01-03T09:30:52.815 0.002 0.000 0.001 30203 2013-01-04T23:03:52.815 0.002 0.000 0.001 30221 2013-01-06T08:10:52.815 0.001 -0.000 0.000 30237 2013-01-07T14:38:52.815 -0.002 0.000 -0.001 30256 2013-01-09T01:18:52.815 -0.001 -0.000 0.000 30275 2013-01-10T12:15:52.815 0.002 -0.000 -0.001 30294 2013-01-12T01:28:52.815 0.006 0.000 -0.000 30305 2013-01-12T22:04:52.815 -0.001 -0.000 0.000 30324 2013-01-14T09:33:52.815 0.005 0.000 -0.000 30340 2013-01-15T14:32:52.815 0.000 0.000 0.000 30356 2013-01-16T21:25:52.815 -0.001 0.000 0.000 30365 2013-01-17T12:53:52.815 0.001 -0.000 -0.001 30384 2013-01-19T00:45:52.815 -0.001 -0.000 0.000 30404 2013-01-20T14:49:52.815 0.002 0.000 0.001 30421 2013-01-21T22:41:22.815 -0.005 0.000 -0.002 30435 2013-01-23T00:51:52.815 0.002 -0.000 0.001 30452 2013-01-24T08:37:52.815 -0.004 0.000 -0.002 30473 2013-01-25T23:43:52.815 -0.003 -0.000 -0.002 30492 2013-01-27T10:13:52.815 -0.000 -0.000 0.000 30511 2013-01-28T22:56:42.815 -0.001 0.000 -0.001 30524 2013-01-29T22:38:52.815 -0.001 0.000 -0.000 30546 2013-01-31T16:23:52.815 0.001 -0.000 0.001 30562 2013-02-01T21:04:52.815 0.001 0.000 -0.000 30579 2013-02-03T06:23:52.815 0.002 -0.000 0.000 30600 2013-02-04T21:20:52.815 0.003 -0.000 0.002 30622 2013-02-06T14:00:22.815 -0.000 -0.000 -0.000 30641 2013-02-08T01:18:52.815 0.004 0.000 -0.001 30660 2013-02-09T13:38:52.814 0.001 -0.000 0.001 30677 2013-02-10T20:08:52.814 -0.002 -0.000 0.001 30698 2013-02-12T12:28:52.814 -0.002 -0.000 -0.001 30717 2013-02-13T23:03:52.814 0.001 0.000 0.000 30739 2013-02-15T17:28:52.814 -0.002 -0.000 -0.001 30761 2013-02-17T09:16:52.814 -0.003 0.000 0.002 30780 2013-02-18T21:56:52.814 -0.003 -0.000 -0.002 30800 2013-02-20T11:25:52.814 0.002 -0.000 0.002 30815 2013-02-21T15:13:52.814 0.003 -0.000 0.003 30832 2013-02-22T22:02:52.814 0.002 -0.000 -0.002 30849 2013-02-24T07:23:52.814 0.000 0.000 -0.000 30866 2013-02-25T14:50:52.814 0.002 -0.000 0.002 30880 2013-02-26T17:18:52.814 -0.001 0.000 -0.000 30893 2013-02-27T17:22:52.814 0.001 -0.000 0.000 30913 2013-03-01T06:46:52.814 -0.002 0.000 -0.003 30930 2013-03-02T14:32:52.814 0.005 0.000 0.005 30943 2013-03-03T13:40:52.814 0.004 0.000 -0.004 30960 2013-03-04T22:12:52.814 0.003 -0.000 0.002 30973 2013-03-05T23:16:52.814 -0.001 0.000 -0.000 30990 2013-03-07T07:05:52.814 0.002 -0.000 0.000 31011 2013-03-08T22:02:52.814 -0.002 0.000 -0.002 31024 2013-03-09T22:19:52.814 -0.003 -0.000 -0.003 31036 2013-03-10T19:37:52.814 -0.000 0.000 0.000 31060 2013-03-12T17:40:52.814 -0.000 -0.000 -0.001 31073 2013-03-13T17:40:52.814 0.002 -0.000 0.001 31097 2013-03-15T14:52:52.814 -0.000 0.001 -0.000 31113 2013-03-16T20:58:52.814 0.000 0.000 0.000 31125 2013-03-17T18:04:52.814 0.001 0.000 -0.001 31144 2013-03-19T06:58:52.814 -0.003 -0.000 -0.002 31157 2013-03-20T07:06:52.814 0.003 -0.000 0.003 31173 2013-03-21T13:21:52.814 -0.000 -0.001 0.000 31191 2013-03-22T21:29:52.814 0.004 0.000 -0.004 31211 2013-03-24T12:23:52.814 0.004 -0.000 0.001 31224 2013-03-25T12:24:52.814 0.001 -0.000 0.000 31238 2013-03-26T14:34:52.814 0.001 -0.001 -0.000 31255 2013-03-27T22:23:52.814 0.003 0.000 0.004 31272 2013-03-29T05:48:52.814 0.000 -0.000 0.000 31285 2013-03-30T05:25:22.814 -0.003 -0.000 0.003 31304 2013-03-31T18:01:52.814 -0.004 0.000 -0.004