Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Mon Jun 1 17:42:11 PDT 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 Extended Science Phase of the MRO mission (orbits 11404 through 12558): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2009 JAN 01 00:01:06.183 2009 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_rec11564_11472_11564_r-v1.bsp spk_psp_rec11626_11563_11626_r-v1.bsp spk_psp_rec11713_11626_11713_r-v1.bsp spk_psp_rec11820_11711_11820_r-v1.bsp spk_psp_rec11924_11818_11924_r-v1.bsp spk_psp_rec12005_11922_12005_r-v1.bsp spk_psp_rec12089_12005_12089_r-v1.bsp spk_psp_rec12147_12083_12147_r-v1.bsp spk_psp_rec12274_12146_12274_r-v1.bsp spk_psp_rec12359_12274_12359_r-v1.bsp spk_psp_rec12461_12359_12461_r-v1.bsp spk_psp_rec12551_12461_12551_r-v1.bsp spk_psp_rec12631_12550_12631_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_psp10.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 11424 2009-01-02T16:00:53.816 -0.001 0.000 0.000 11442 2009-01-04T01:04:53.815 -0.001 0.000 0.000 11472 2009-01-06T09:03:53.815 -0.000 0.000 0.000 11489 2009-01-07T16:53:53.815 0.000 -0.000 -0.000 11506 2009-01-09T02:18:53.815 0.001 -0.000 -0.000 11525 2009-01-10T12:08:53.815 0.001 -0.000 -0.000 11541 2009-01-11T17:58:53.815 0.000 0.000 -0.000 11563 2009-01-13T11:21:53.815 -0.003 -0.000 0.002 11576 2009-01-14T11:39:53.815 -0.004 -0.000 0.002 11591 2009-01-15T15:51:53.815 -0.001 0.000 0.001 11606 2009-01-16T20:35:53.815 0.001 0.000 0.000 11626 2009-01-18T09:10:53.815 0.002 -0.000 -0.002 11640 2009-01-19T11:18:53.815 0.002 -0.000 -0.001 11655 2009-01-20T15:58:53.815 -0.000 -0.000 -0.000 11678 2009-01-22T10:53:53.815 -0.001 -0.000 0.000 11695 2009-01-23T18:08:53.815 0.001 0.000 -0.001 11711 2009-01-25T01:38:53.815 -0.002 -0.000 -0.000 11736 2009-01-26T22:38:53.815 0.000 0.000 -0.000 11767 2009-01-29T09:17:53.815 0.000 0.000 -0.000 11780 2009-01-30T09:07:53.815 0.001 0.000 -0.001 11797 2009-01-31T16:51:53.815 0.001 -0.000 -0.001 11818 2009-02-02T08:12:53.815 -0.000 0.000 0.000 11839 2009-02-03T23:23:53.815 -0.000 0.000 0.000 11857 2009-02-05T09:11:53.815 -0.003 -0.000 0.002 11869 2009-02-06T08:08:53.815 0.001 -0.000 -0.000 11893 2009-02-08T04:27:53.815 -0.000 -0.000 0.000 11922 2009-02-10T12:08:53.814 -0.000 0.000 -0.000 11942 2009-02-11T23:58:53.814 -0.000 -0.000 0.000 11957 2009-02-13T05:23:53.814 0.000 -0.000 -0.000 11978 2009-02-14T20:58:53.814 -0.002 -0.000 0.000 12005 2009-02-16T21:53:53.814 0.001 -0.000 -0.001 12025 2009-02-18T11:17:53.814 -0.000 0.000 0.000 12044 2009-02-19T22:48:53.814 0.000 0.000 -0.000 12062 2009-02-21T08:28:53.814 -0.000 0.000 0.000 12074 2009-02-22T07:41:53.814 -0.000 -0.000 -0.000 12083 2009-02-22T23:38:53.814 0.000 0.000 0.001 12102 2009-02-24T11:17:53.814 -0.001 0.000 0.001 12123 2009-02-26T02:33:53.814 -0.000 0.000 0.000 12146 2009-02-27T21:28:53.814 -0.001 0.000 0.001 12164 2009-03-01T07:23:53.814 0.001 -0.000 -0.002 12181 2009-03-02T14:58:53.814 -0.000 0.000 -0.001 12198 2009-03-03T22:38:53.814 0.001 0.000 -0.001 12216 2009-03-05T08:26:53.814 -0.000 -0.000 0.000 12235 2009-03-06T19:58:53.814 0.000 0.000 -0.000 12252 2009-03-08T03:47:23.814 -0.000 0.000 0.001 12274 2009-03-09T20:55:53.814 0.001 0.000 -0.002 12293 2009-03-11T08:26:53.814 0.001 -0.000 -0.001 12317 2009-03-13T05:20:53.814 0.000 0.000 -0.000 12338 2009-03-14T21:23:53.814 -0.001 -0.000 -0.001 12359 2009-03-16T11:43:53.814 0.000 0.000 -0.000 12379 2009-03-18T01:13:53.814 0.001 -0.000 -0.002 12399 2009-03-19T16:08:53.814 -0.001 -0.000 -0.000 12422 2009-03-21T11:08:53.814 -0.000 -0.000 0.000 12441 2009-03-22T22:48:53.814 0.001 0.000 -0.000 12461 2009-03-24T10:37:53.814 -0.000 0.000 0.000 12479 2009-03-25T20:13:53.814 0.000 0.000 -0.000 12500 2009-03-27T11:28:53.814 -0.001 -0.000 0.001 12518 2009-03-28T21:33:53.814 -0.000 0.000 0.000 12537 2009-03-30T08:53:53.814 0.000 0.000 -0.001 12550 2009-03-31T09:09:53.814 -0.001 -0.000 0.001