Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Fri Nov 6 07:51:41 PST 2015 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 41845 through 43025): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2015 JUL 01 00:01:09.000 2015 OCT 01 01:01:08.182 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_rec41887_41758_41887_r-v1.bsp spk_psp_rec41982_41880_41982_r-v1.bsp spk_psp_rec42073_41977_42073_r-v1.bsp spk_psp_rec42162_42067_42162_r-v1.bsp spk_psp_rec42240_42154_42240_r-v1.bsp spk_psp_rec42318_42237_42318_r-v1.bsp spk_psp_rec42430_42312_42430_r-v1.bsp spk_psp_rec42523_42428_42523_r-v1.bsp spk_psp_rec42611_42519_42611_r-v1.bsp spk_psp_rec42691_42605_42691_r-v1.bsp spk_psp_rec42791_42685_42791_r-v1.bsp spk_psp_rec42874_42786_42874_r-v1.bsp spk_psp_rec42969_42867_42969_r-v1.bsp spk_psp_rec43055_42963_43055_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_psp36.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 41865 2015-07-02T15:11:51.815 -0.003 0.000 0.001 41880 2015-07-03T18:46:28.815 -0.000 0.000 0.001 41907 2015-07-05T22:24:09.366 -0.001 0.000 -0.001 41920 2015-07-06T22:42:56.226 -0.001 -0.000 -0.001 41931 2015-07-07T19:17:27.136 -0.001 -0.000 -0.001 41946 2015-07-08T23:20:36.036 0.002 0.000 0.003 41970 2015-07-10T20:13:47.956 -0.001 -0.000 -0.002 41977 2015-07-11T08:17:15.816 -0.000 -0.000 0.000 41997 2015-07-12T22:43:39.976 0.000 -0.000 0.000 42022 2015-07-14T21:28:06.106 0.001 -0.000 0.001 42035 2015-07-15T21:47:37.216 -0.001 0.000 -0.001 42048 2015-07-16T22:06:18.356 0.000 -0.000 0.000 42067 2015-07-18T08:37:00.816 -0.001 0.000 0.002 42084 2015-07-19T16:54:51.816 -0.001 0.000 -0.000 42100 2015-07-20T23:21:04.206 -0.000 -0.000 -0.000 42110 2015-07-21T17:39:11.416 0.001 0.000 0.001 42123 2015-07-22T17:37:52.716 -0.001 0.000 0.001 42138 2015-07-23T22:25:04.126 -0.000 0.000 -0.001 42154 2015-07-25T04:06:37.816 -0.000 -0.000 -0.000 42174 2015-07-26T17:46:00.216 0.000 0.000 0.000 42185 2015-07-27T13:34:13.586 -0.000 0.000 0.000 42199 2015-07-28T16:20:07.106 0.000 -0.000 0.000 42210 2015-07-29T12:43:51.816 0.001 -0.000 0.001 42223 2015-07-30T11:48:51.816 0.000 -0.000 0.000 42237 2015-07-31T14:27:26.816 -0.000 -0.000 0.000 42264 2015-08-02T17:22:33.926 -0.000 0.000 0.000 42274 2015-08-03T12:22:49.436 0.000 -0.000 0.000 42292 2015-08-04T22:26:29.396 -0.001 0.000 -0.001 42302 2015-08-05T17:08:31.816 0.001 -0.000 0.001 42312 2015-08-06T10:44:18.816 0.000 0.000 -0.000 42343 2015-08-08T21:48:45.396 0.001 -0.000 0.001 42356 2015-08-09T22:07:51.816 0.000 0.000 0.001 42372 2015-08-11T04:03:29.816 0.001 -0.000 0.001 42382 2015-08-11T22:45:17.016 -0.000 0.000 -0.001 42394 2015-08-12T21:11:43.887 -0.001 0.000 -0.001 42403 2015-08-13T14:01:32.547 -0.000 0.000 -0.000 42428 2015-08-15T11:43:15.817 -0.000 -0.000 0.000 42446 2015-08-16T22:26:17.947 0.001 0.000 0.001 42459 2015-08-17T22:44:56.047 -0.001 -0.000 -0.002 42472 2015-08-18T23:03:32.167 -0.001 0.000 -0.002 42484 2015-08-19T21:29:58.237 0.001 0.000 0.002 42499 2015-08-21T01:23:51.817 -0.000 -0.000 -0.001 42519 2015-08-22T13:56:09.817 0.000 0.000 -0.000 42544 2015-08-24T13:38:51.817 -0.001 -0.000 -0.002 42558 2015-08-25T15:21:51.817 0.001 0.000 0.000 42574 2015-08-26T21:51:45.137 0.001 0.000 0.001 42587 2015-08-27T22:10:27.547 -0.001 -0.000 -0.001 42605 2015-08-29T06:43:12.817 0.000 0.000 0.000 42623 2015-08-30T17:29:56.627 0.000 0.000 0.001 42638 2015-08-31T21:08:10.367 0.000 -0.000 0.000 42650 2015-09-01T19:59:38.837 -0.001 0.000 -0.001 42664 2015-09-02T22:10:23.557 0.000 -0.000 -0.000 42677 2015-09-03T22:29:07.187 0.000 0.000 0.001 42685 2015-09-04T13:02:30.817 -0.000 0.000 -0.000 42715 2015-09-06T21:33:31.157 0.001 0.000 0.001 42727 2015-09-07T19:59:49.777 -0.001 0.000 -0.001 42741 2015-09-08T22:10:44.707 0.000 -0.000 0.000 42751 2015-09-09T16:13:00.067 -0.001 0.000 0.000 42769 2015-09-11T02:32:25.697 0.001 0.000 0.002 42786 2015-09-12T09:18:26.817 -0.001 0.000 0.002 42803 2015-09-13T18:07:54.747 -0.000 -0.000 -0.001 42818 2015-09-14T22:11:02.047 -0.000 0.000 -0.001 42831 2015-09-15T22:28:58.067 0.000 0.000 0.001 42850 2015-09-17T09:52:51.817 -0.000 0.000 -0.000 42867 2015-09-18T16:42:19.817 0.000 -0.000 -0.000 42893 2015-09-20T17:38:49.137 -0.000 -0.000 0.000 42908 2015-09-21T22:29:20.777 0.001 0.000 0.002 42921 2015-09-22T22:11:32.977 -0.000 -0.000 0.000 42933 2015-09-23T21:14:36.147 -0.000 0.000 0.000 42947 2015-09-24T23:25:25.647 -0.000 -0.000 -0.001 42963 2015-09-26T04:51:46.817 0.000 -0.000 0.000 42984 2015-09-27T20:36:57.437 0.000 0.000 0.001 42999 2015-09-29T00:40:51.817 -0.000 -0.000 -0.000 43011 2015-09-29T23:06:22.557 -0.000 0.000 -0.000 43019 2015-09-30T14:04:05.097 -0.001 -0.000 -0.002