Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Wed Oct 30 15:18:17 PDT 2019 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 60595 through 61775): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2019 JUL 01 00:01:10.000 2019 OCT 01 01:01:09.182 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_rec60681_60593_60681_r-v1.bsp spk_psp_rec60760_60680_60760_r-v1.bsp spk_psp_rec60862_60759_60862_r-v1.bsp spk_psp_rec60953_60860_60953_r-v1.bsp spk_psp_rec61042_60951_61042_r-v1.bsp spk_psp_rec61122_61040_61122_r-v1.bsp spk_psp_rec61212_61120_61212_r-v1.bsp spk_psp_rec61311_61210_61311_r-v1.bsp spk_psp_rec61491_61309_61491_r-v1.bsp spk_psp_rec61567_61488_61567_r-v1.bsp spk_psp_rec61670_61565_61670_r-v1.bsp spk_psp_rec61755_61670_61755_r-v1.bsp spk_psp_rec61837_61753_61837_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_psp52.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 60607 2019-07-01T23:57:50.815 -0.003 0.000 -0.000 60617 2019-07-02T19:12:50.815 -0.000 0.000 -0.000 60633 2019-07-04T01:08:50.815 -0.000 -0.000 -0.000 60647 2019-07-05T02:57:50.815 0.000 -0.000 0.000 60665 2019-07-06T12:05:50.816 -0.001 0.000 0.000 60680 2019-07-07T15:52:50.816 -0.002 -0.000 0.001 60695 2019-07-08T20:30:50.816 -0.000 0.000 0.000 60707 2019-07-09T19:08:50.816 -0.005 0.000 -0.003 60719 2019-07-10T17:57:50.816 0.007 -0.000 0.006 60732 2019-07-11T18:16:50.816 -0.002 -0.000 -0.001 60746 2019-07-12T20:25:50.816 0.001 -0.000 0.001 60759 2019-07-13T19:36:50.816 0.002 0.000 -0.001 60778 2019-07-15T08:17:50.816 0.002 -0.000 0.001 60797 2019-07-16T19:49:50.816 0.002 0.000 0.001 60809 2019-07-17T18:15:50.816 0.000 0.000 0.000 60825 2019-07-18T23:57:50.816 -0.005 0.000 -0.004 60836 2019-07-19T20:45:50.816 0.003 -0.000 0.003 60850 2019-07-20T22:55:50.816 -0.000 0.000 -0.000 60860 2019-07-21T16:29:50.816 0.001 -0.000 -0.001 60875 2019-07-22T21:40:50.816 0.003 0.000 0.003 60889 2019-07-23T23:51:50.816 0.000 -0.000 0.000 60902 2019-07-24T23:07:50.816 -0.001 0.000 0.001 60915 2019-07-26T00:20:50.816 -0.001 0.000 -0.001 60931 2019-07-27T06:24:50.816 0.002 0.000 0.001 60951 2019-07-28T18:40:50.816 0.002 -0.000 -0.002 60967 2019-07-30T01:43:50.816 -0.002 0.000 -0.002 60977 2019-07-30T20:24:50.816 0.002 0.000 0.002 60999 2019-08-01T13:33:50.816 0.003 -0.000 0.003 61017 2019-08-02T23:12:50.816 0.000 -0.000 0.000 61030 2019-08-03T23:22:50.816 0.001 -0.000 0.001 61040 2019-08-04T17:06:50.816 0.003 -0.000 -0.003 61059 2019-08-06T05:45:50.816 0.000 -0.000 0.000 61076 2019-08-07T13:32:50.816 0.001 0.000 0.001 61088 2019-08-08T11:58:50.816 -0.002 0.000 -0.002 61107 2019-08-09T23:30:50.816 0.003 0.000 0.003 61120 2019-08-10T22:53:50.816 -0.006 0.000 0.005 61136 2019-08-12T05:37:50.816 -0.005 0.000 -0.005 61149 2019-08-13T06:06:50.817 0.002 0.000 0.002 61169 2019-08-14T19:26:50.817 -0.005 -0.000 -0.005 61186 2019-08-16T03:14:50.817 0.001 -0.000 0.001 61198 2019-08-17T01:32:50.817 -0.001 0.000 -0.001 61210 2019-08-17T23:00:50.817 -0.002 -0.000 0.002 61230 2019-08-19T13:22:50.817 -0.002 0.000 -0.002 61251 2019-08-21T04:53:50.817 -0.002 0.000 -0.003 61268 2019-08-22T12:02:50.817 0.001 -0.000 0.000 61286 2019-08-23T22:13:50.817 -0.001 0.000 -0.000 61297 2019-08-24T18:47:50.817 -0.002 0.000 -0.003 61309 2019-08-25T16:08:50.817 0.003 -0.000 -0.004 61320 2019-08-26T13:48:50.817 0.002 -0.000 0.003 61338 2019-08-27T23:33:50.817 -0.000 0.000 -0.000 61488 2019-09-08T14:51:50.817 0.000 -0.000 -0.000 61504 2019-09-09T21:51:50.817 0.001 -0.000 0.001 61514 2019-09-10T15:46:50.817 -0.001 -0.000 0.000 61532 2019-09-12T01:21:50.817 0.000 -0.000 -0.001 61545 2019-09-13T02:27:50.817 -0.001 0.000 -0.001 61565 2019-09-14T14:49:50.817 -0.002 0.000 0.002 61587 2019-09-16T09:03:50.817 -0.001 0.000 -0.001 61604 2019-09-17T16:24:50.817 -0.002 0.000 -0.001 61627 2019-09-19T11:22:50.817 0.001 0.000 0.000 61643 2019-09-20T17:46:50.817 -0.002 0.000 -0.002 61658 2019-09-21T21:48:50.817 0.002 0.000 0.003 61670 2019-09-22T19:47:50.817 -0.001 0.000 -0.000 61684 2019-09-23T22:25:50.817 -0.000 0.000 -0.001 61697 2019-09-24T22:44:50.817 0.001 0.000 0.002 61711 2019-09-25T23:57:50.817 -0.001 -0.000 0.001 61736 2019-09-27T23:39:50.817 -0.001 -0.000 -0.002 61746 2019-09-28T17:52:50.817 -0.002 0.000 -0.000 61753 2019-09-29T06:52:50.817 0.004 -0.000 -0.001 61768 2019-09-30T11:08:50.817 0.000 -0.000 0.000