Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu Jul 9 13:17:30 PDT 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 40677 through 41844): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2015 APR 01 00:01:08.000 2015 JUL 01 01:01:08.184 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_rec40808_40722_40808_r-v1.bsp spk_psp_rec40904_40802_40904_r-v1.bsp spk_psp_rec40996_40898_40996_r-v1.bsp spk_psp_rec41079_40993_41079_r-v1.bsp spk_psp_rec41171_41072_41171_r-v1.bsp spk_psp_rec41259_41161_41259_r-v1.bsp spk_psp_rec41351_41252_41351_r-v1.bsp spk_psp_rec41445_41344_41445_r-v1.bsp spk_psp_rec41516_41438_41516_r-v1.bsp spk_psp_rec41765_41495_41765_r-v1.bsp spk_psp_rec41887_41758_41887_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_psp35.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 40686 2015-04-01T18:58:52.814 0.002 -0.000 0.001 40715 2015-04-04T00:46:52.814 0.002 0.000 0.002 40722 2015-04-04T13:00:52.814 -0.001 -0.000 0.001 40740 2015-04-05T23:57:52.814 -0.001 0.000 -0.000 40749 2015-04-06T16:29:52.814 0.002 -0.000 0.002 40760 2015-04-07T12:24:52.814 -0.000 -0.000 0.000 40772 2015-04-08T11:34:52.814 -0.000 -0.000 -0.000 40792 2015-04-10T01:19:48.814 0.001 -0.000 0.000 40802 2015-04-10T18:38:52.814 0.000 0.000 -0.000 40829 2015-04-12T22:34:28.814 -0.001 0.000 0.000 40844 2015-04-14T02:33:52.814 -0.002 0.000 -0.000 40863 2015-04-15T14:06:52.814 0.001 0.000 0.000 40893 2015-04-17T22:06:52.814 -0.001 -0.000 -0.001 40898 2015-04-18T06:12:32.814 0.001 0.000 -0.001 40919 2015-04-19T22:03:58.814 0.001 -0.000 0.000 40943 2015-04-21T19:48:52.814 -0.000 -0.000 -0.000 40968 2015-04-23T18:32:52.814 -0.001 -0.000 0.000 40975 2015-04-24T06:39:52.814 0.002 -0.000 -0.000 40993 2015-04-25T15:46:52.814 0.001 -0.000 -0.001 41009 2015-04-26T22:49:52.814 -0.002 0.000 -0.002 41033 2015-04-28T19:11:42.814 -0.001 0.000 -0.000 41055 2015-04-30T13:13:52.814 0.001 0.000 0.000 41072 2015-05-01T19:32:52.814 -0.000 -0.000 0.000 41099 2015-05-03T23:10:52.814 -0.004 0.000 -0.003 41113 2015-05-05T01:43:52.814 0.005 0.000 0.000 41128 2015-05-06T05:04:32.814 -0.001 -0.000 -0.001 41147 2015-05-07T16:56:52.814 -0.000 0.000 0.000 41161 2015-05-08T18:45:11.814 -0.000 -0.000 0.001 41188 2015-05-10T21:38:23.304 -0.002 -0.000 -0.002 41196 2015-05-11T12:34:34.444 0.000 -0.000 0.000 41209 2015-05-12T12:54:54.074 -0.000 -0.000 -0.001 41225 2015-05-13T18:25:16.424 0.003 -0.000 0.002 41234 2015-05-14T11:38:04.484 -0.000 0.000 0.000 41247 2015-05-15T11:56:37.154 -0.002 0.000 -0.002 41252 2015-05-15T20:09:45.814 0.000 -0.000 -0.000 41278 2015-05-17T21:56:14.084 -0.001 0.000 -0.001 41289 2015-05-18T18:29:59.024 0.000 0.000 0.000 41299 2015-05-19T13:09:52.814 -0.000 0.000 0.000 41317 2015-05-20T22:51:58.374 -0.000 0.000 -0.000 41330 2015-05-21T23:09:52.814 -0.001 0.000 -0.001 41344 2015-05-23T00:12:47.814 0.001 -0.000 -0.001 41368 2015-05-24T22:15:23.804 0.001 -0.000 0.001 41381 2015-05-25T22:33:52.684 -0.002 0.001 -0.002 41391 2015-05-26T17:16:17.834 0.002 -0.000 0.002 41407 2015-05-27T23:11:42.514 -0.003 0.000 -0.001 41430 2015-05-29T18:12:59.655 0.002 0.000 0.003 41438 2015-05-30T08:04:00.815 0.001 0.000 -0.000 41456 2015-05-31T18:50:52.815 -0.002 0.000 -0.002 41471 2015-06-01T22:55:34.515 0.003 0.000 0.003 41484 2015-06-02T23:14:27.565 -0.003 0.000 -0.002 41495 2015-06-03T18:40:00.815 0.002 -0.000 -0.003 41517 2015-06-05T12:58:52.815 0.003 -0.000 0.004 41536 2015-06-07T00:30:04.965 -0.005 0.000 -0.006 41550 2015-06-08T01:50:01.085 0.006 -0.000 -0.008 41575 2015-06-10T01:28:52.815 -0.002 0.001 -0.002 41704 2015-06-20T02:43:52.815 0.002 -0.000 0.001 41729 2015-06-22T00:49:45.845 -0.000 0.000 -0.000 41758 2015-06-24T06:36:26.815 0.003 -0.000 -0.005 41779 2015-06-25T22:58:54.095 -0.000 0.000 0.001 41803 2015-06-27T19:52:37.815 -0.000 -0.000 -0.001 41817 2015-06-28T22:03:59.025 0.000 0.000 0.000 41830 2015-06-29T22:23:19.715 -0.001 -0.000 -0.001 41843 2015-06-30T22:42:11.415 0.004 -0.001 0.005