Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue Feb 19 12:10:43 PST 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 57092 through 58271): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2018 OCT 01 00:01:10.000 2019 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_rec57180_57074_57180_r-v1.bsp spk_psp_rec57261_57179_57261_r-v1.bsp spk_psp_rec57360_57258_57360_r-v1.bsp spk_psp_rec57448_57358_57448_r-v1.bsp spk_psp_rec57531_57445_57531_r-v1.bsp spk_psp_rec57616_57510_57616_r-v1.bsp spk_psp_rec57712_57614_57712_r-v1.bsp spk_psp_rec57809_57709_57809_r-v1.bsp spk_psp_rec57899_57806_57899_r-v1.bsp spk_psp_rec57988_57895_57988_r-v1.bsp spk_psp_rec58065_57986_58065_r-v1.bsp spk_psp_rec58168_58062_58168_r-v1.bsp spk_psp_rec58271_58165_58271_r-v1.bsp spk_psp_rec58347_58269_58347_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_psp49.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 57098 2018-10-01T13:44:50.817 -0.001 -0.000 -0.000 57116 2018-10-02T22:49:50.817 -0.000 0.000 0.000 57129 2018-10-03T23:34:50.817 0.013 0.000 -0.000 57142 2018-10-04T23:28:50.817 -0.002 -0.000 0.000 57154 2018-10-05T23:07:50.817 0.005 -0.000 0.001 57167 2018-10-06T23:18:50.817 0.010 0.000 0.002 57179 2018-10-07T21:06:50.817 0.008 -0.000 0.000 57189 2018-10-08T15:28:50.817 0.018 0.000 -0.004 57206 2018-10-09T23:29:50.817 -0.008 0.000 0.000 57226 2018-10-11T13:42:50.817 -0.011 0.000 -0.001 57244 2018-10-12T23:20:50.817 0.005 -0.000 0.001 57258 2018-10-14T01:59:50.817 -0.004 0.000 0.001 57278 2018-10-15T14:52:50.817 -0.004 0.000 -0.001 57295 2018-10-16T22:39:50.817 0.007 -0.000 0.001 57308 2018-10-17T22:57:50.817 -0.003 0.000 -0.000 57333 2018-10-19T21:41:50.817 0.002 0.000 0.000 57345 2018-10-20T20:07:50.817 0.025 -0.000 0.004 57358 2018-10-21T19:53:50.817 -0.026 0.000 -0.005 57376 2018-10-23T06:08:50.817 0.003 -0.000 0.000 57397 2018-10-24T21:19:50.817 -0.003 0.000 -0.001 57418 2018-10-26T11:20:50.817 -0.021 -0.000 0.007 57432 2018-10-27T14:45:50.817 -0.003 0.000 -0.000 57445 2018-10-28T15:37:50.817 0.016 0.000 -0.005 57458 2018-10-29T14:53:50.817 -0.002 0.000 -0.001 57471 2018-10-30T14:48:50.817 -0.008 0.000 0.001 57488 2018-10-31T22:12:50.817 0.040 0.000 -0.013 57496 2018-11-01T14:24:50.817 -0.004 -0.000 -0.001 57510 2018-11-02T17:04:50.817 -0.005 -0.000 0.001 57531 2018-11-04T06:50:50.817 -0.012 -0.000 0.003 57548 2018-11-05T14:35:50.817 0.015 0.000 -0.005 57565 2018-11-06T22:59:50.817 0.001 -0.000 0.000 57578 2018-11-07T22:57:50.817 0.004 -0.000 -0.000 57590 2018-11-08T22:03:50.817 -0.027 0.000 -0.008 57603 2018-11-09T22:57:50.817 0.009 0.000 -0.003 57614 2018-11-10T19:20:50.817 -0.003 -0.000 0.000 57637 2018-11-12T14:00:50.817 0.019 0.000 0.004 57649 2018-11-13T11:37:50.817 -0.010 0.000 0.001 57666 2018-11-14T20:13:50.817 -0.009 0.000 -0.002 57676 2018-11-15T14:11:50.817 0.001 0.000 -0.000 57692 2018-11-16T20:50:50.817 -0.018 0.000 -0.004 57709 2018-11-18T03:54:50.817 0.006 -0.000 0.000 57729 2018-11-19T18:00:50.817 -0.007 -0.000 -0.002 57745 2018-11-20T22:51:50.817 0.016 0.000 -0.006 57757 2018-11-21T22:21:50.817 -0.019 -0.000 -0.005 57771 2018-11-22T23:57:50.817 -0.001 -0.000 -0.000 57783 2018-11-23T22:51:50.817 0.003 0.000 0.001 57796 2018-11-24T22:51:50.817 0.006 0.000 0.002 57806 2018-11-25T16:58:50.817 -0.005 0.000 0.001 57822 2018-11-26T23:51:50.817 -0.001 0.000 -0.000 57834 2018-11-27T22:45:50.816 -0.006 0.000 0.002 57847 2018-11-28T22:36:50.816 0.002 -0.000 0.000 57860 2018-11-29T22:06:50.816 0.001 -0.000 -0.000 57873 2018-11-30T22:45:50.816 0.005 0.000 0.002 57886 2018-12-01T22:46:50.816 -0.004 -0.000 0.000 57895 2018-12-02T16:40:50.816 0.012 0.000 -0.002 57911 2018-12-03T22:14:50.816 0.004 0.000 0.001 57924 2018-12-04T22:33:50.816 -0.007 0.000 -0.002 57937 2018-12-05T22:40:50.816 0.007 -0.000 0.003 57950 2018-12-06T22:44:50.816 -0.001 -0.000 -0.000 57963 2018-12-07T22:29:50.816 -0.008 -0.000 0.002 57976 2018-12-08T22:41:50.816 0.013 0.000 -0.005 57986 2018-12-09T17:34:50.816 -0.003 -0.000 0.001 58001 2018-12-10T22:30:50.816 -0.002 -0.000 -0.001 58014 2018-12-11T22:41:50.816 0.003 -0.000 0.001 58027 2018-12-12T22:39:50.816 -0.002 -0.000 -0.001 58052 2018-12-14T21:52:50.816 -0.003 -0.000 -0.001 58062 2018-12-15T16:58:50.816 -0.005 -0.000 0.001 58082 2018-12-17T05:57:50.816 0.007 0.000 0.002 58099 2018-12-18T12:50:50.816 -0.005 0.000 0.002 58116 2018-12-19T21:30:50.816 -0.008 0.000 -0.003 58134 2018-12-21T06:09:50.816 0.007 -0.000 -0.004 58155 2018-12-22T22:31:50.816 0.001 -0.000 0.000 58165 2018-12-23T17:40:50.816 0.004 0.000 -0.001 58182 2018-12-24T23:57:50.816 0.001 0.000 -0.000 58192 2018-12-25T19:42:50.816 -0.014 0.000 -0.006 58207 2018-12-26T22:31:50.816 0.010 0.000 -0.005 58232 2018-12-28T22:28:50.816 -0.008 -0.000 -0.004 58245 2018-12-29T22:29:50.816 -0.003 -0.000 -0.001 58258 2018-12-30T22:28:50.816 -0.002 -0.000 0.000 58269 2018-12-31T20:16:50.816 0.002 0.000 -0.001