Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Fri Oct 30 12:54:15 PDT 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 65292 through 66472): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2020 JUL 01 00:01:10.000 2020 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_rec65355_65263_65355_r-v1.bsp spk_psp_rec65445_65353_65445_r-v1.bsp spk_psp_rec65535_65443_65535_r-v1.bsp spk_psp_rec65619_65533_65619_r-v1.bsp spk_psp_rec65714_65617_65714_r-v1.bsp spk_psp_rec65804_65714_65804_r-v1.bsp spk_psp_rec65894_65802_65894_r-v1.bsp spk_psp_rec65977_65892_65977_r-v1.bsp spk_psp_rec66072_65975_66072_r-v1.bsp spk_psp_rec66162_66070_66162_r-v1.bsp spk_psp_rec66253_66161_66253_r-v1.bsp spk_psp_rec66343_66251_66343_r-v1.bsp spk_psp_rec66425_66341_66425_r-v1.bsp spk_psp_rec66523_66423_66523_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_psp56.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 65298 2020-07-01T13:05:50.815 -0.000 -0.000 -0.001 65315 2020-07-02T20:53:50.815 0.000 -0.000 0.000 65329 2020-07-03T23:03:50.815 0.000 0.000 0.004 65341 2020-07-04T21:27:50.816 -0.000 0.000 -0.004 65353 2020-07-05T19:22:50.816 0.000 -0.000 -0.000 65372 2020-07-07T07:28:50.816 -0.000 -0.000 -0.002 65390 2020-07-08T17:07:50.816 -0.000 -0.000 -0.001 65402 2020-07-09T15:33:50.816 0.000 -0.000 0.001 65419 2020-07-10T23:20:50.816 -0.000 -0.000 -0.002 65432 2020-07-11T23:39:50.816 0.000 0.000 0.001 65443 2020-07-12T19:11:50.816 -0.000 0.000 0.002 65461 2020-07-14T05:52:50.816 0.000 -0.000 0.000 65477 2020-07-15T11:40:50.816 -0.000 0.000 -0.002 65495 2020-07-16T21:27:50.816 0.000 -0.000 0.001 65508 2020-07-17T21:45:50.816 -0.000 0.000 -0.001 65522 2020-07-18T23:53:50.816 0.000 0.000 0.002 65533 2020-07-19T20:11:50.816 0.000 0.000 0.001 65550 2020-07-21T04:17:50.816 0.000 0.000 0.001 65568 2020-07-22T13:56:50.816 -0.000 0.000 -0.003 65581 2020-07-23T14:14:50.816 0.000 -0.000 0.001 65599 2020-07-24T23:33:50.816 -0.000 0.000 -0.001 65608 2020-07-25T16:43:50.816 -0.000 -0.000 -0.000 65617 2020-07-26T08:31:50.816 -0.000 0.000 0.001 65633 2020-07-27T15:19:50.816 -0.000 0.000 -0.003 65650 2020-07-28T23:15:50.816 0.000 -0.000 0.003 65663 2020-07-29T23:28:50.816 0.000 0.000 0.001 65681 2020-07-31T09:18:50.816 -0.000 -0.000 -0.001 65701 2020-08-01T22:37:50.816 -0.000 0.000 -0.005 65714 2020-08-02T21:51:50.816 -0.001 0.000 0.006 65727 2020-08-03T23:13:50.816 -0.000 0.000 0.001 65746 2020-08-05T10:44:50.816 -0.000 0.000 -0.001 65761 2020-08-06T14:41:50.816 -0.000 -0.000 -0.001 65778 2020-08-07T22:34:50.816 0.000 -0.000 0.002 65791 2020-08-08T22:52:50.816 -0.000 0.000 -0.000 65802 2020-08-09T18:46:50.816 0.000 -0.000 -0.000 65817 2020-08-10T22:58:50.816 0.000 0.000 -0.000 65839 2020-08-12T16:36:50.817 -0.000 -0.000 -0.001 65851 2020-08-13T14:40:50.817 0.000 0.000 0.000 65868 2020-08-14T22:47:50.817 -0.000 -0.000 -0.000 65885 2020-08-16T06:38:50.817 -0.000 -0.000 -0.001 65892 2020-08-16T18:40:50.817 0.000 0.000 -0.000 65906 2020-08-17T21:39:50.817 0.000 -0.000 0.001 65926 2020-08-19T11:15:50.817 0.000 -0.000 0.001 65945 2020-08-20T22:28:50.817 0.000 0.000 0.000 65959 2020-08-21T23:57:50.817 0.000 -0.000 -0.000 65975 2020-08-23T06:05:50.817 -0.000 0.000 0.001 65991 2020-08-24T12:28:50.817 -0.000 0.000 -0.001 66005 2020-08-25T14:39:50.817 -0.000 0.000 -0.001 66017 2020-08-26T13:23:50.817 0.001 0.000 0.004 66031 2020-08-27T15:33:50.817 -0.001 0.000 -0.003 66047 2020-08-28T21:28:50.817 0.000 0.000 0.000 66060 2020-08-29T21:46:50.817 0.000 -0.000 0.000 66070 2020-08-30T15:30:50.817 -0.000 -0.000 0.001 66084 2020-08-31T18:38:50.817 0.000 0.000 0.000 66093 2020-09-01T11:27:50.817 -0.000 0.000 -0.000 66111 2020-09-02T21:06:50.817 0.000 -0.000 0.001 66128 2020-09-04T04:53:50.817 -0.000 -0.000 -0.000 66148 2020-09-05T18:17:50.817 0.000 0.000 0.002 66161 2020-09-06T17:40:50.817 -0.001 0.000 0.002 66181 2020-09-08T07:59:50.817 -0.000 0.000 -0.002 66200 2020-09-09T19:30:50.817 -0.000 -0.000 -0.001 66215 2020-09-10T23:32:50.817 0.000 -0.000 0.000 66226 2020-09-11T20:07:50.817 -0.000 -0.000 -0.000 66239 2020-09-12T20:25:50.817 -0.000 -0.000 -0.000 66251 2020-09-13T17:49:50.817 -0.001 -0.000 0.002 66266 2020-09-14T22:54:50.817 -0.000 0.000 0.000 66287 2020-09-16T14:10:50.817 -0.001 -0.000 -0.003 66300 2020-09-17T14:28:50.817 0.001 0.000 0.003 66317 2020-09-18T22:15:50.817 -0.001 -0.000 -0.002 66326 2020-09-19T14:57:50.817 0.001 -0.000 0.003 66341 2020-09-20T18:10:50.817 0.001 -0.000 -0.001 66356 2020-09-21T23:10:50.817 0.001 -0.000 0.001 66377 2020-09-23T14:25:50.817 -0.000 0.000 -0.001 66390 2020-09-24T14:44:50.817 -0.000 0.000 -0.000 66407 2020-09-25T22:31:50.817 -0.001 0.000 -0.001 66423 2020-09-27T03:22:50.817 -0.001 -0.000 0.001 66441 2020-09-28T14:04:50.817 0.000 -0.000 -0.000 66458 2020-09-29T21:51:50.817 0.000 -0.000 0.001 66472 2020-09-30T23:57:50.817 0.000 -0.000 0.001