Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Mon May 9 14:10:47 PDT 2016 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 44206 through 45374): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2016 JAN 01 00:01:09.000 2016 APR 01 01:01:08.185 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_rec44208_44122_44208_r-v1.bsp spk_psp_rec44316_44203_44316_r-v1.bsp spk_psp_rec44392_44309_44392_r-v1.bsp spk_psp_rec44493_44391_44493_r-v1.bsp spk_psp_rec44581_44491_44581_r-v1.bsp spk_psp_rec44676_44580_44676_r-v1.bsp spk_psp_rec44749_44671_44749_r-v1.bsp spk_psp_rec44848_44747_44848_r-v1.bsp spk_psp_rec44956_44845_44956_r-v1.bsp spk_psp_rec45047_44954_45047_r-v1.bsp spk_psp_rec45137_45045_45137_r-v1.bsp spk_psp_rec45227_45135_45227_r-v1.bsp spk_psp_rec45315_45225_45315_r-v1.bsp spk_psp_rec45402_45313_45402_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_psp38.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 44227 2016-01-02T16:06:51.816 -0.000 -0.000 0.001 44241 2016-01-03T19:02:51.816 -0.000 0.000 0.000 44264 2016-01-05T14:04:58.048 0.000 0.000 0.000 44277 2016-01-06T14:23:21.815 -0.000 -0.000 -0.000 44293 2016-01-07T20:18:09.205 0.000 -0.000 -0.000 44309 2016-01-09T01:12:50.815 0.000 -0.000 -0.001 44332 2016-01-10T21:13:33.308 0.000 -0.000 0.002 44346 2016-01-11T23:24:06.753 -0.000 -0.000 -0.001 44356 2016-01-12T17:05:51.441 0.000 0.000 -0.001 44370 2016-01-13T20:16:35.115 0.000 0.000 0.001 44382 2016-01-14T18:42:43.808 -0.001 0.000 -0.003 44391 2016-01-15T10:28:07.815 0.000 -0.000 -0.002 44419 2016-01-17T15:53:29.815 -0.000 0.000 -0.001 44432 2016-01-18T16:11:46.815 0.000 -0.000 0.000 44445 2016-01-19T16:29:58.552 0.000 -0.000 0.001 44458 2016-01-20T16:47:43.676 0.000 -0.000 0.001 44483 2016-01-22T15:31:51.815 -0.000 -0.000 -0.003 44491 2016-01-23T05:28:51.815 -0.000 0.000 0.003 44509 2016-01-24T16:11:41.815 -0.000 -0.000 -0.001 44523 2016-01-25T17:48:21.815 0.002 0.000 0.001 44537 2016-01-26T20:32:41.815 -0.002 -0.000 -0.013 44549 2016-01-27T18:44:21.815 -0.001 0.000 -0.005 44562 2016-01-28T19:14:51.815 0.001 -0.000 0.003 44580 2016-01-30T03:49:35.815 -0.000 -0.000 -0.000 44598 2016-01-31T14:34:12.201 0.000 0.000 0.000 44614 2016-02-01T20:29:17.574 0.000 0.000 0.001 44638 2016-02-03T17:21:19.136 0.000 0.000 0.001 44652 2016-02-04T19:31:53.716 -0.001 0.000 -0.003 44671 2016-02-06T05:57:40.815 0.000 0.000 -0.001 44688 2016-02-07T14:50:37.065 0.000 -0.000 0.002 44701 2016-02-08T15:06:51.815 -0.000 -0.000 -0.001 44714 2016-02-09T15:24:51.815 -0.000 0.000 -0.001 44727 2016-02-10T15:43:51.814 0.000 -0.000 0.002 44741 2016-02-11T17:40:51.814 0.000 -0.000 0.001 44747 2016-02-12T04:09:00.814 -0.001 -0.000 0.003 44769 2016-02-13T21:44:51.814 -0.000 -0.000 -0.000 44791 2016-02-15T15:22:51.814 0.000 -0.000 0.000 44804 2016-02-16T15:41:51.814 -0.000 0.000 -0.002 44815 2016-02-17T12:14:51.814 0.000 0.000 0.002 44827 2016-02-18T10:41:51.814 0.000 0.000 0.000 44845 2016-02-19T19:57:00.814 -0.000 0.000 -0.000 44865 2016-02-21T09:04:51.814 0.000 0.000 -0.000 44882 2016-02-22T17:06:51.814 -0.000 -0.000 -0.001 44894 2016-02-23T15:34:51.814 0.000 -0.000 0.001 44910 2016-02-24T21:51:51.814 -0.000 -0.000 -0.001 44920 2016-02-25T16:33:51.814 0.000 -0.000 0.001 44937 2016-02-27T00:21:51.814 -0.000 0.000 -0.002 44954 2016-02-28T07:10:00.814 0.001 -0.000 -0.003 44970 2016-02-29T14:02:51.814 0.000 -0.000 0.001 44983 2016-03-01T14:21:51.814 0.000 0.000 0.000 44994 2016-03-02T10:54:51.814 -0.000 -0.000 -0.001 45008 2016-03-03T13:05:51.814 0.000 0.000 0.001 45027 2016-03-05T00:36:51.814 -0.000 0.000 -0.000 45045 2016-03-06T09:13:00.814 -0.000 0.000 0.000 45058 2016-03-07T10:34:51.814 -0.000 -0.000 -0.001 45066 2016-03-08T00:46:51.814 0.000 -0.000 0.000 45086 2016-03-09T14:55:51.814 0.000 -0.000 0.002 45099 2016-03-10T15:13:51.814 -0.000 0.000 -0.001 45117 2016-03-12T00:22:51.814 0.000 -0.000 0.000 45135 2016-03-13T09:29:00.814 -0.000 0.000 0.001 45150 2016-03-14T14:34:51.814 -0.001 -0.000 -0.003 45159 2016-03-15T07:24:51.814 0.000 -0.000 0.001 45180 2016-03-16T22:39:51.814 0.000 0.000 0.000 45189 2016-03-17T15:29:51.814 0.000 0.000 0.000 45210 2016-03-19T06:44:51.814 0.000 0.000 0.001 45225 2016-03-20T09:45:00.814 -0.001 0.000 0.003 45240 2016-03-21T14:36:51.814 -0.000 -0.000 -0.001 45252 2016-03-22T13:16:51.814 -0.000 0.000 -0.001 45264 2016-03-23T11:05:51.814 0.000 -0.000 -0.000 45275 2016-03-24T07:39:51.814 0.000 -0.000 -0.000 45295 2016-03-25T21:40:51.814 0.000 -0.000 0.000 45313 2016-03-27T06:16:00.814 0.000 -0.000 -0.001 45329 2016-03-28T13:14:51.814 0.001 0.000 0.002 45341 2016-03-29T11:40:51.814 -0.001 0.000 -0.001 45355 2016-03-30T13:50:51.814 -0.000 0.000 -0.000 45367 2016-03-31T12:16:51.814 -0.000 0.000 -0.000