Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Fri Nov 17 07:47:11 PST 2017 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 51226 through 52406): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2017 JUL 01 00:01:10.000 2017 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_rec51263_51158_51263_r-v1.bsp spk_psp_rec51340_51261_51340_r-v1.bsp spk_psp_rec51430_51338_51430_r-v1.bsp spk_psp_rec51481_51428_51481_r-v1.bsp spk_psp_rec51687_51479_51687_r-v1.bsp spk_psp_rec51789_51685_51789_r-v1.bsp spk_psp_rec51873_51787_51873_r-v1.bsp spk_psp_rec51969_51871_51969_r-v1.bsp spk_psp_rec52057_51967_52057_r-v1.bsp spk_psp_rec52145_52052_52145_r-v1.bsp spk_psp_rec52237_52143_52237_r-v1.bsp spk_psp_rec52344_52235_52344_r-v1.bsp spk_psp_rec52415_52342_52415_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_psp44.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 51237 2017-07-01T22:31:50.815 0.001 0.000 0.002 51250 2017-07-02T22:50:50.815 -0.003 -0.000 -0.004 51261 2017-07-03T18:57:50.815 0.004 0.000 0.001 51276 2017-07-04T23:27:50.815 -0.001 0.000 -0.001 51296 2017-07-06T12:45:50.816 0.001 -0.000 0.001 51314 2017-07-07T22:32:50.816 0.001 -0.000 0.000 51324 2017-07-08T17:14:50.816 -0.001 0.000 -0.001 51338 2017-07-09T18:18:50.816 0.001 -0.000 -0.001 51360 2017-07-11T12:33:50.816 0.000 -0.000 0.000 51379 2017-07-12T23:57:50.816 -0.000 0.000 -0.001 51392 2017-07-13T23:57:50.816 0.004 0.000 0.002 51404 2017-07-14T22:51:50.816 -0.006 -0.000 -0.008 51417 2017-07-15T23:10:50.816 0.003 -0.000 0.004 51428 2017-07-16T18:37:50.816 -0.003 -0.000 0.004 51440 2017-07-17T18:10:50.816 -0.003 0.000 -0.004 51464 2017-07-19T15:03:50.816 -0.000 -0.000 -0.001 51479 2017-07-20T17:38:20.816 -0.001 0.000 0.000 51640 2017-08-02T06:38:50.816 0.002 0.000 0.001 51658 2017-08-03T17:47:50.816 -0.002 -0.000 -0.002 51673 2017-08-04T21:55:50.816 0.002 -0.000 0.003 51685 2017-08-05T19:15:50.816 0.001 0.000 -0.001 51712 2017-08-07T22:51:50.816 0.002 0.000 0.004 51722 2017-08-08T17:33:50.816 -0.002 -0.000 -0.004 51737 2017-08-09T21:36:50.816 0.000 0.000 0.001 51763 2017-08-11T22:13:50.816 -0.000 0.000 -0.000 51776 2017-08-12T22:32:50.817 0.000 -0.000 0.000 51787 2017-08-13T18:01:50.817 -0.003 -0.000 0.005 51803 2017-08-15T01:02:50.817 -0.003 -0.000 -0.005 51824 2017-08-16T16:18:50.817 -0.000 -0.000 -0.001 51841 2017-08-18T00:06:50.817 0.000 0.000 0.001 51861 2017-08-19T13:28:50.817 0.000 0.000 0.001 51871 2017-08-20T07:06:50.817 -0.001 -0.000 0.001 51886 2017-08-21T12:15:50.817 -0.001 0.000 -0.002 51905 2017-08-22T23:47:50.817 0.002 0.000 0.002 51918 2017-08-23T23:57:50.817 -0.002 0.000 -0.003 51928 2017-08-24T18:47:50.817 0.002 -0.000 0.003 51944 2017-08-26T00:42:50.817 -0.001 -0.000 -0.001 51967 2017-08-27T18:38:50.817 0.000 0.000 -0.000 51982 2017-08-28T23:46:50.817 0.001 -0.000 0.001 51995 2017-08-29T23:57:50.817 -0.001 -0.000 -0.002 52007 2017-08-30T22:31:50.817 0.000 0.000 0.001 52020 2017-08-31T22:50:50.817 -0.001 -0.000 -0.002 52036 2017-09-02T04:46:50.817 0.001 0.000 0.002 52052 2017-09-03T09:37:50.817 -0.001 0.000 0.002 52071 2017-09-04T21:37:50.817 0.001 0.000 -0.000 52080 2017-09-05T15:02:50.817 -0.001 -0.000 -0.001 52095 2017-09-06T19:05:50.817 -0.000 -0.000 -0.000 52106 2017-09-07T15:35:50.817 0.001 -0.000 0.002 52123 2017-09-08T23:27:50.817 -0.002 -0.000 -0.002 52134 2017-09-09T20:01:50.817 0.001 -0.000 0.001 52143 2017-09-10T11:46:50.817 -0.000 -0.000 0.000 52155 2017-09-11T11:17:50.817 0.000 0.000 0.001 52174 2017-09-12T22:49:50.817 -0.001 0.000 -0.003 52187 2017-09-13T23:13:50.817 0.001 0.000 0.002 52202 2017-09-15T03:08:50.817 0.001 -0.000 0.002 52226 2017-09-16T23:57:50.817 -0.000 0.000 -0.001 52235 2017-09-17T15:50:50.817 -0.001 0.000 0.002 52264 2017-09-19T23:09:50.817 0.001 -0.000 0.002 52276 2017-09-20T21:40:50.817 -0.002 0.000 -0.003 52286 2017-09-21T16:17:50.817 0.002 -0.000 0.003 52303 2017-09-22T23:57:50.817 -0.001 0.000 -0.001 52325 2017-09-24T17:14:50.817 -0.002 -0.000 -0.004 52342 2017-09-25T23:58:50.817 0.001 0.000 -0.001 52367 2017-09-27T23:20:50.817 -0.001 0.000 -0.000 52376 2017-09-28T16:37:50.817 0.001 0.000 0.002 52393 2017-09-29T23:57:50.817 -0.002 0.000 -0.001 52404 2017-09-30T20:30:50.817 0.001 0.000 0.000