Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu Feb 15 14:58:07 PST 2018 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 52407 through 53587): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2017 OCT 01 00:01:10.000 2018 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_rec52415_52342_52415_r-v1.bsp spk_psp_rec52502_52413_52502_r-v1.bsp spk_psp_rec52586_52500_52586_r-v1.bsp spk_psp_rec52681_52584_52681_r-v1.bsp spk_psp_rec52775_52679_52775_r-v1.bsp spk_psp_rec52860_52773_52860_r-v1.bsp spk_psp_rec52957_52858_52957_r-v1.bsp spk_psp_rec53047_52955_53047_r-v1.bsp spk_psp_rec53137_53045_53137_r-v1.bsp spk_psp_rec53226_53135_53226_r-v1.bsp spk_psp_rec53316_53224_53316_r-v1.bsp spk_psp_rec53391_53314_53391_r-v1.bsp spk_psp_rec53496_53389_53496_r-v1.bsp spk_psp_rec53586_53494_53586_r-v1.bsp spk_psp_rec53676_53584_53676_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_psp45.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 52413 2017-10-01T13:22:50.817 -0.001 0.000 -0.001 52424 2017-10-02T10:24:50.817 -0.000 -0.000 -0.000 52436 2017-10-03T08:50:50.817 0.001 -0.000 0.002 52453 2017-10-04T16:38:50.817 -0.002 -0.000 -0.004 52465 2017-10-05T15:04:50.817 0.001 0.000 0.001 52482 2017-10-06T22:52:50.817 -0.001 0.000 -0.001 52495 2017-10-07T23:08:50.817 -0.001 0.000 -0.003 52500 2017-10-08T07:36:50.817 0.001 -0.000 -0.003 52514 2017-10-09T10:43:50.817 -0.001 0.000 -0.002 52530 2017-10-10T16:38:50.817 -0.001 0.000 -0.002 52546 2017-10-11T21:59:50.817 0.002 -0.000 -0.001 52571 2017-10-13T21:20:50.817 -0.000 -0.000 -0.001 52584 2017-10-14T20:34:50.817 -0.000 0.000 0.000 52599 2017-10-16T01:41:50.817 0.001 0.000 0.001 52624 2017-10-17T23:54:50.817 0.000 -0.000 -0.000 52637 2017-10-18T23:57:50.817 -0.001 0.000 0.001 52645 2017-10-19T14:58:50.817 0.000 0.000 -0.001 52662 2017-10-20T23:31:50.817 -0.001 -0.000 -0.002 52679 2017-10-22T06:15:50.817 0.000 -0.000 -0.001 52694 2017-10-23T11:22:50.817 0.000 -0.000 0.001 52710 2017-10-24T16:24:50.817 0.001 -0.000 -0.003 52723 2017-10-25T17:29:50.817 -0.001 -0.000 -0.002 52733 2017-10-26T12:18:50.817 -0.000 -0.000 -0.001 52752 2017-10-27T23:50:50.817 0.000 -0.000 0.001 52764 2017-10-28T22:17:50.817 -0.001 -0.000 -0.003 52773 2017-10-29T14:03:50.817 -0.000 0.000 0.000 52784 2017-10-30T11:33:50.817 -0.001 -0.000 -0.003 52803 2017-10-31T23:14:50.817 0.001 0.000 0.002 52823 2017-11-02T12:39:50.817 -0.000 0.000 -0.000 52842 2017-11-03T23:57:50.817 0.000 -0.000 0.000 52858 2017-11-05T05:20:50.817 -0.001 0.000 0.002 52875 2017-11-06T13:54:50.817 -0.001 -0.000 -0.002 52895 2017-11-08T03:22:20.817 -0.000 -0.000 -0.001 52919 2017-11-09T23:46:50.817 0.000 -0.000 0.000 52932 2017-11-10T23:57:50.817 0.000 -0.000 -0.000 52944 2017-11-11T22:56:50.817 -0.000 0.000 -0.000 52955 2017-11-12T18:50:50.817 -0.000 -0.000 0.000 52970 2017-11-13T23:34:50.817 -0.000 -0.000 -0.001 52983 2017-11-14T23:53:50.817 -0.001 0.000 -0.001 53003 2017-11-16T13:17:50.817 0.000 0.000 0.001 53021 2017-11-17T22:56:50.817 0.001 0.000 0.002 53034 2017-11-18T23:15:50.817 -0.000 0.000 -0.001 53045 2017-11-19T18:45:50.817 -0.000 0.000 0.001 53053 2017-11-20T10:47:50.817 -0.001 0.000 -0.003 53079 2017-11-22T11:25:50.817 0.001 -0.000 0.002 53098 2017-11-23T22:57:50.817 0.000 -0.000 0.001 53111 2017-11-24T23:16:50.817 0.000 0.000 0.000 53124 2017-11-25T23:34:50.817 -0.000 0.000 -0.000 53135 2017-11-26T19:04:50.817 -0.000 -0.000 0.000 53150 2017-11-27T23:57:50.816 -0.001 -0.000 -0.002 53162 2017-11-28T22:38:50.816 0.000 -0.000 -0.000 53175 2017-11-29T22:57:50.816 0.001 -0.000 0.002 53201 2017-12-01T23:34:50.816 -0.000 -0.000 -0.000 53211 2017-12-02T18:16:50.816 0.001 -0.000 0.002 53224 2017-12-03T18:09:50.816 0.000 0.000 -0.000 53239 2017-12-04T22:32:50.816 0.001 -0.000 0.002 53254 2017-12-06T02:26:50.816 -0.000 -0.000 -0.000 53271 2017-12-07T10:29:50.816 -0.000 0.000 -0.000 53291 2017-12-08T23:53:50.816 -0.000 -0.000 -0.000 53304 2017-12-09T23:56:50.816 0.001 -0.000 0.002 53314 2017-12-10T17:57:50.816 0.000 0.000 -0.000 53329 2017-12-11T22:51:50.816 0.000 -0.000 0.000 53352 2017-12-13T17:08:50.816 -0.000 0.000 0.000 53361 2017-12-14T10:47:50.816 0.001 -0.000 0.003 53380 2017-12-15T22:19:50.816 -0.001 -0.000 -0.002 53389 2017-12-16T14:05:50.816 0.000 -0.000 -0.000 53406 2017-12-17T22:42:50.816 -0.000 0.000 -0.001 53432 2017-12-19T23:34:50.816 0.000 0.000 0.001 53444 2017-12-20T21:06:50.816 0.000 -0.000 -0.001 53457 2017-12-21T22:19:50.816 0.000 -0.000 0.001 53470 2017-12-22T22:38:50.816 -0.000 -0.000 -0.001 53483 2017-12-23T22:57:50.816 -0.001 -0.000 -0.002 53494 2017-12-24T18:27:50.816 0.001 -0.000 -0.002 53509 2017-12-25T23:34:50.816 0.000 -0.000 0.001 53521 2017-12-26T22:01:50.816 -0.000 0.000 -0.000 53533 2017-12-27T20:27:50.816 -0.000 -0.000 -0.000 53548 2017-12-28T23:57:50.816 0.000 -0.000 -0.000 53560 2017-12-29T22:57:50.816 0.000 -0.000 0.001 53573 2017-12-30T23:15:50.816 -0.001 0.000 -0.002 53584 2017-12-31T18:45:50.816 -0.000 0.000 0.000