Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Wed Feb 5 13:29:56 PST 2020 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 61776 through 62956): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2019 OCT 01 00:01:10.000 2020 JAN 01 01:01:09.183 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_rec61837_61753_61837_r-v1.bsp spk_psp_rec61928_61835_61928_r-v1.bsp spk_psp_rec62031_61928_62031_r-v1.bsp spk_psp_rec62121_62031_62121_r-v1.bsp spk_psp_rec62211_62119_62211_r-v1.bsp spk_psp_rec62296_62211_62296_r-v1.bsp spk_psp_rec62390_62294_62390_r-v1.bsp spk_psp_rec62479_62389_62479_r-v1.bsp spk_psp_rec62563_62477_62563_r-v1.bsp spk_psp_rec62646_62563_62646_r-v1.bsp spk_psp_rec62746_62645_62746_r-v1.bsp spk_psp_rec62839_62745_62839_r-v1.bsp spk_psp_rec62929_62837_62929_r-v1.bsp spk_psp_rec63015_62927_63015_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_psp53.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 61786 2019-10-01T21:09:50.817 -0.001 0.000 -0.002 61796 2019-10-02T15:27:50.817 0.002 -0.000 0.001 61812 2019-10-03T21:44:50.817 -0.002 -0.000 -0.004 61823 2019-10-04T17:47:50.817 0.004 0.000 -0.000 61835 2019-10-05T15:54:50.817 -0.001 0.000 0.001 61857 2019-10-07T09:54:50.817 -0.002 -0.000 -0.003 61876 2019-10-08T21:26:50.817 0.002 0.000 0.003 61896 2019-10-10T09:52:50.817 -0.001 0.000 0.001 61916 2019-10-11T23:57:50.817 -0.000 0.000 -0.000 61928 2019-10-12T21:35:50.817 0.001 -0.000 -0.001 61948 2019-10-14T11:55:50.817 -0.001 -0.000 -0.001 61960 2019-10-15T10:29:50.817 0.001 0.000 0.001 61976 2019-10-16T16:22:50.817 0.002 -0.000 0.003 61989 2019-10-17T16:22:50.817 -0.003 -0.000 -0.002 62006 2019-10-18T23:51:50.817 -0.000 -0.000 -0.000 62017 2019-10-19T20:07:50.817 0.001 -0.000 -0.002 62031 2019-10-20T22:22:50.817 -0.001 0.000 0.001 62044 2019-10-21T23:33:50.817 -0.001 0.000 -0.002 62056 2019-10-22T21:58:50.817 0.001 -0.000 0.001 62068 2019-10-23T20:26:50.817 0.001 -0.000 0.002 62083 2019-10-24T23:57:50.817 -0.001 0.000 0.000 62094 2019-10-25T20:22:50.817 -0.001 0.000 0.001 62107 2019-10-26T21:22:50.817 0.001 -0.000 0.002 62119 2019-10-27T18:45:50.817 0.001 0.000 -0.001 62133 2019-10-28T21:35:50.817 0.001 -0.000 0.001 62146 2019-10-29T22:19:50.817 -0.002 -0.000 -0.002 62158 2019-10-30T20:46:50.817 0.001 0.000 0.002 62172 2019-10-31T22:20:50.817 -0.000 0.000 0.000 62185 2019-11-01T23:16:50.817 0.001 -0.000 0.001 62197 2019-11-02T21:42:50.817 -0.000 -0.000 -0.000 62211 2019-11-03T22:49:50.817 -0.000 -0.000 0.000 62232 2019-11-05T15:10:50.817 0.000 -0.000 0.000 62256 2019-11-07T12:04:50.817 0.000 0.000 0.001 62275 2019-11-08T23:36:50.817 0.001 0.000 0.002 62288 2019-11-09T23:55:50.817 -0.002 -0.000 -0.003 62294 2019-11-10T10:04:50.817 0.001 0.000 -0.001 62312 2019-11-11T20:48:50.817 0.001 0.000 0.002 62332 2019-11-13T10:13:50.817 -0.001 0.000 -0.001 62359 2019-11-15T12:03:50.817 -0.001 -0.000 0.001 62376 2019-11-16T20:31:50.817 0.001 0.000 0.002 62389 2019-11-17T19:45:50.817 -0.000 -0.000 0.000 62402 2019-11-18T21:08:50.817 -0.001 0.000 -0.001 62414 2019-11-19T19:35:50.817 0.001 -0.000 0.001 62428 2019-11-20T21:34:50.817 0.001 -0.000 0.002 62453 2019-11-22T20:31:50.817 -0.001 -0.000 -0.002 62467 2019-11-23T22:43:50.817 -0.000 -0.000 -0.000 62477 2019-11-24T16:21:50.817 0.001 0.000 -0.001 62492 2019-11-25T21:28:50.817 0.000 -0.000 0.001 62505 2019-11-26T21:44:50.817 0.000 -0.000 -0.000 62531 2019-11-28T22:25:50.816 0.000 -0.000 0.001 62545 2019-11-30T00:36:50.816 -0.000 -0.000 -0.000 62563 2019-12-01T09:12:50.816 -0.000 0.000 0.000 62581 2019-12-02T19:56:50.816 -0.000 0.000 -0.001 62595 2019-12-03T21:18:50.816 0.000 0.000 -0.001 62607 2019-12-04T20:33:50.816 -0.001 0.000 -0.001 62621 2019-12-05T22:04:50.816 0.000 -0.000 -0.000 62632 2019-12-06T19:19:50.816 -0.001 -0.000 -0.002 62645 2019-12-07T18:34:50.816 0.003 -0.000 -0.005 62659 2019-12-08T21:35:50.816 0.001 0.000 0.001 62679 2019-12-10T11:13:50.816 0.000 0.000 0.000 62695 2019-12-11T17:09:50.816 0.001 0.000 0.002 62710 2019-12-12T20:45:50.816 0.001 -0.000 0.000 62722 2019-12-13T19:39:50.816 -0.001 -0.000 -0.002 62736 2019-12-14T21:37:50.816 0.000 0.000 0.000 62745 2019-12-15T13:36:50.816 -0.001 -0.000 0.002 62762 2019-12-16T22:28:50.816 0.000 0.000 0.000 62774 2019-12-17T20:54:50.816 -0.000 0.000 -0.000 62786 2019-12-18T19:21:50.816 0.001 -0.000 0.001 62800 2019-12-19T21:32:50.816 -0.000 0.000 -0.001 62814 2019-12-20T23:43:50.816 -0.001 -0.000 -0.001 62827 2019-12-21T23:35:50.816 0.001 -0.000 0.000 62837 2019-12-22T17:49:50.816 -0.001 -0.000 0.002 62859 2019-12-24T11:58:50.816 -0.000 0.000 -0.001 62875 2019-12-25T16:55:50.816 -0.000 0.000 0.000 62897 2019-12-27T10:31:50.816 0.001 -0.000 0.000 62913 2019-12-28T16:53:50.816 -0.001 0.000 -0.001 62927 2019-12-29T18:09:50.816 -0.000 -0.000 0.001 62940 2019-12-30T19:22:50.816 0.001 -0.000 0.001 62955 2019-12-31T22:31:50.816 -0.002 -0.000 0.003