Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue Nov 1 09:49:38 PDT 2022 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 74663 through 75843): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2022 JUL 01 00:01:10.000 2022 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_rec74700_74603_74700_r-v1.bsp spk_psp_rec74785_74696_74785_r-v1.bsp spk_psp_rec74877_74783_74877_r-v1.bsp spk_psp_rec74961_74875_74961_r-v1.bsp spk_psp_rec75054_74959_75054_r-v1.bsp spk_psp_rec75146_75052_75146_r-v1.bsp spk_psp_rec75236_75144_75236_r-v1.bsp spk_psp_rec75329_75234_75329_r-v1.bsp spk_psp_rec75416_75327_75416_r-v1.bsp spk_psp_rec75505_75414_75505_r-v1.bsp spk_psp_rec75590_75499_75590_r-v1.bsp spk_psp_rec75680_75588_75680_r-v1.bsp spk_psp_rec75777_75678_75777_r-v1.bsp spk_psp_rec75865_75776_75865_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_psp64.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 74671 2022-07-01T17:29:50.815 -0.000 -0.000 -0.023 74681 2022-07-02T11:29:50.815 -0.000 -0.000 -0.012 74696 2022-07-03T15:25:50.815 0.000 -0.000 -0.011 74716 2022-07-05T05:33:50.815 -0.000 -0.000 0.021 74737 2022-07-06T20:03:50.816 0.000 0.000 0.021 74749 2022-07-07T18:54:50.816 0.000 0.000 -0.010 74762 2022-07-08T19:08:50.816 -0.001 0.000 -0.011 74777 2022-07-09T23:39:50.816 0.000 -0.000 -0.027 74783 2022-07-10T09:57:50.816 -0.000 -0.000 -0.026 74803 2022-07-11T23:57:50.816 -0.000 -0.000 -0.000 74811 2022-07-12T15:21:50.816 -0.000 0.000 0.007 74827 2022-07-13T21:17:50.816 -0.000 0.000 0.007 74845 2022-07-15T06:57:50.816 0.000 -0.000 -0.008 74860 2022-07-16T11:01:50.816 -0.000 0.000 0.002 74875 2022-07-17T14:03:50.816 0.000 0.000 0.000 74891 2022-07-18T21:00:50.816 -0.000 0.000 -0.001 74903 2022-07-19T19:26:50.816 0.000 0.000 -0.002 74922 2022-07-21T06:53:50.816 -0.000 -0.000 0.003 74943 2022-07-22T22:15:50.816 0.000 -0.000 -0.005 74959 2022-07-24T03:09:50.816 -0.000 -0.000 -0.000 74976 2022-07-25T11:58:50.816 -0.000 0.000 0.004 74993 2022-07-26T19:46:50.816 0.000 -0.000 -0.008 75008 2022-07-27T23:50:50.816 -0.000 0.000 0.004 75024 2022-07-29T05:44:50.816 0.000 0.000 -0.007 75041 2022-07-30T12:53:50.816 -0.001 0.000 -0.004 75052 2022-07-31T09:06:50.816 0.000 -0.000 0.004 75066 2022-08-01T12:18:50.816 0.000 -0.000 -0.004 75080 2022-08-02T14:29:50.816 0.000 -0.000 -0.001 75091 2022-08-03T11:03:50.816 -0.001 0.000 0.008 75102 2022-08-04T07:37:50.816 0.000 -0.000 -0.003 75119 2022-08-05T15:25:50.816 -0.000 -0.000 0.002 75132 2022-08-06T15:44:50.816 -0.000 -0.000 0.001 75144 2022-08-07T13:10:50.816 0.000 0.000 0.001 75157 2022-08-08T14:29:50.816 -0.000 0.000 0.001 75172 2022-08-09T18:32:50.816 0.000 -0.000 -0.002 75188 2022-08-10T23:57:50.816 -0.000 0.000 -0.000 75209 2022-08-12T15:44:50.817 -0.000 -0.000 0.002 75224 2022-08-13T19:47:50.817 0.000 0.000 -0.005 75234 2022-08-14T13:30:50.817 -0.000 -0.000 -0.001 75246 2022-08-15T12:05:50.817 -0.000 0.000 0.001 75260 2022-08-16T14:55:50.817 -0.000 -0.000 0.000 75272 2022-08-17T13:33:50.817 -0.000 -0.000 0.005 75286 2022-08-18T15:45:50.817 0.000 -0.000 -0.003 75303 2022-08-19T23:31:50.817 0.000 -0.000 -0.003 75316 2022-08-20T23:49:50.817 -0.001 0.000 0.007 75327 2022-08-21T19:25:50.817 0.000 0.000 0.004 75353 2022-08-23T21:02:50.817 0.000 -0.000 -0.002 75367 2022-08-24T23:12:50.817 0.000 -0.000 0.000 75383 2022-08-26T05:06:50.817 0.000 0.000 -0.003 75399 2022-08-27T11:02:50.817 -0.000 -0.000 0.001 75414 2022-08-28T14:06:50.817 0.000 -0.000 0.002 75435 2022-08-30T06:06:50.817 0.000 -0.000 -0.001 75452 2022-08-31T13:36:50.817 -0.000 -0.000 -0.000 75468 2022-09-01T19:21:50.817 -0.001 -0.000 -0.001 75483 2022-09-02T23:26:50.817 0.000 -0.000 0.001 75499 2022-09-04T05:03:50.817 -0.000 -0.000 -0.001 75519 2022-09-05T19:16:50.817 0.000 0.000 -0.004 75543 2022-09-07T16:21:50.817 -0.000 -0.000 0.002 75563 2022-09-09T05:26:50.817 -0.000 -0.000 -0.000 75580 2022-09-10T13:28:50.817 0.000 -0.000 -0.000 75588 2022-09-11T03:28:50.817 0.000 0.000 0.004 75605 2022-09-12T12:01:50.817 0.000 0.000 -0.004 75618 2022-09-13T12:31:50.817 -0.000 0.000 0.004 75630 2022-09-14T10:45:50.817 0.000 -0.000 -0.001 75645 2022-09-15T14:32:50.817 -0.000 -0.000 -0.000 75656 2022-09-16T11:21:50.817 -0.000 -0.000 -0.001 75668 2022-09-17T10:02:50.817 -0.000 -0.000 0.002 75678 2022-09-18T03:47:50.817 -0.000 0.000 -0.002 75694 2022-09-19T10:40:50.817 -0.000 0.000 0.002 75707 2022-09-20T10:59:50.817 0.000 -0.000 -0.003 75720 2022-09-21T11:18:50.817 -0.000 0.000 0.002 75746 2022-09-23T11:55:50.817 0.000 -0.000 -0.003 75760 2022-09-24T14:07:50.817 -0.000 0.000 0.001 75776 2022-09-25T19:42:50.817 -0.000 -0.000 0.005 75795 2022-09-27T07:35:50.817 -0.000 -0.000 0.005 75812 2022-09-28T14:45:50.817 -0.000 -0.000 -0.001 75831 2022-09-30T02:55:50.817 0.000 -0.000 -0.003