Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Mon Aug 13 08:56:18 PDT 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 54743 through 55910): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2018 APR 01 00:01:10.000 2018 JUL 01 01:01:09.184 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_rec54753_54660_54753_r-v1.bsp spk_psp_rec54836_54752_54836_r-v1.bsp spk_psp_rec54932_54835_54932_r-v1.bsp spk_psp_rec55020_54930_55020_r-v1.bsp spk_psp_rec55114_55018_55114_r-v1.bsp spk_psp_rec55195_55112_55195_r-v1.bsp spk_psp_rec55293_55194_55293_r-v1.bsp spk_psp_rec55379_55291_55379_r-v1.bsp spk_psp_rec55462_55377_55462_r-v1.bsp spk_psp_rec55559_55460_55559_r-v1.bsp spk_psp_rec55637_55557_55637_r-v1.bsp spk_psp_rec55741_55635_55741_r-v1.bsp spk_psp_rec55831_55739_55831_r-v1.bsp spk_psp_rec55922_55829_55922_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_psp47.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 54752 2018-04-01T19:35:50.814 0.000 0.000 0.000 54767 2018-04-02T23:35:50.814 0.000 -0.000 0.000 54788 2018-04-04T15:19:50.814 -0.001 0.000 -0.003 54805 2018-04-05T23:06:50.814 -0.000 -0.000 -0.000 54818 2018-04-06T23:24:50.814 0.000 -0.000 0.001 54835 2018-04-08T06:07:50.814 0.000 0.000 -0.000 54852 2018-04-09T14:52:50.814 0.000 -0.000 0.001 54866 2018-04-10T17:08:50.814 -0.000 0.000 -0.001 54882 2018-04-11T23:05:50.814 0.000 -0.000 0.001 54895 2018-04-12T23:23:50.814 -0.000 0.000 -0.000 54908 2018-04-13T23:42:50.814 -0.000 0.000 -0.001 54921 2018-04-14T23:57:50.814 0.000 -0.000 0.001 54930 2018-04-15T15:46:50.814 0.000 0.000 -0.001 54944 2018-04-16T19:01:50.814 0.000 -0.000 0.001 54958 2018-04-17T21:12:50.814 -0.000 0.000 -0.000 54972 2018-04-18T23:21:50.814 0.000 -0.000 0.000 54985 2018-04-19T23:41:50.814 -0.000 -0.000 -0.001 54998 2018-04-20T23:57:50.814 -0.000 0.000 -0.001 55009 2018-04-21T19:51:50.814 -0.000 -0.000 0.000 55018 2018-04-22T12:21:20.814 0.000 -0.000 -0.001 55046 2018-04-24T17:49:20.814 -0.000 -0.000 -0.000 55072 2018-04-26T18:22:50.814 0.000 -0.000 0.001 55087 2018-04-27T22:24:50.814 0.000 0.000 0.000 55097 2018-04-28T16:37:50.814 -0.000 0.000 -0.000 55112 2018-04-29T20:05:50.814 -0.001 -0.000 0.002 55132 2018-05-01T10:33:50.814 -0.000 0.000 -0.002 55148 2018-05-02T16:12:50.814 0.001 0.000 0.002 55164 2018-05-03T22:24:50.814 -0.000 -0.000 -0.001 55177 2018-05-04T22:42:50.814 -0.000 -0.000 -0.000 55194 2018-05-06T06:02:50.814 0.000 0.000 0.000 55212 2018-05-07T16:09:50.814 0.000 -0.000 0.000 55225 2018-05-08T16:27:50.814 -0.001 -0.000 -0.002 55246 2018-05-10T07:43:50.814 0.000 -0.000 0.001 55265 2018-05-11T19:15:50.814 -0.000 -0.000 -0.002 55276 2018-05-12T15:49:50.814 -0.000 0.000 -0.001 55291 2018-05-13T19:12:50.814 0.000 0.000 -0.000 55310 2018-05-15T07:24:50.814 0.000 0.000 0.001 55327 2018-05-16T15:11:50.814 -0.000 0.000 -0.001 55340 2018-05-17T15:30:50.814 0.000 -0.000 0.000 55356 2018-05-18T21:25:50.814 0.000 -0.000 0.001 55377 2018-05-20T11:36:50.814 -0.000 -0.000 0.001 55391 2018-05-21T14:51:50.814 0.000 0.000 0.000 55403 2018-05-22T13:18:50.814 0.000 -0.000 0.001 55420 2018-05-23T21:05:50.814 -0.001 -0.000 -0.002 55435 2018-05-25T00:24:50.814 -0.000 0.000 0.000 55447 2018-05-25T23:34:50.814 0.000 -0.000 0.001 55460 2018-05-26T22:48:50.814 -0.000 -0.000 0.001 55481 2018-05-28T15:09:50.815 0.000 0.000 0.001 55492 2018-05-29T11:43:50.815 -0.000 -0.000 -0.001 55506 2018-05-30T13:54:50.815 0.000 -0.000 0.001 55519 2018-05-31T14:12:50.815 -0.000 0.000 -0.000 55537 2018-06-01T23:51:50.815 0.000 -0.000 0.000 55550 2018-06-02T23:53:50.815 -0.001 0.000 -0.001 55557 2018-06-03T12:11:50.815 0.001 -0.000 -0.002 55570 2018-06-04T13:34:50.815 0.000 0.000 0.000 55584 2018-06-05T15:44:50.815 -0.000 -0.000 -0.001 55600 2018-06-06T21:24:50.815 0.000 0.000 0.001 55617 2018-06-08T05:27:50.815 -0.001 0.000 -0.002 55635 2018-06-09T14:10:50.815 0.000 0.000 -0.000 55652 2018-06-10T22:53:50.815 -0.001 0.000 -0.002 55665 2018-06-11T23:12:50.815 0.001 0.000 0.001 55685 2018-06-13T12:25:50.815 0.000 -0.000 -0.000 55699 2018-06-14T14:46:50.815 0.001 -0.000 0.002 55716 2018-06-15T22:34:50.815 -0.000 -0.000 -0.000 55729 2018-06-16T22:52:50.815 0.000 0.000 0.000 55739 2018-06-17T16:29:50.815 -0.000 -0.000 0.000 55756 2018-06-19T01:21:50.815 0.001 -0.000 0.002 55771 2018-06-20T05:24:50.815 -0.001 0.000 -0.001 55788 2018-06-21T13:11:50.815 -0.000 -0.000 -0.001 55805 2018-06-22T20:58:50.815 0.001 0.000 0.001 55819 2018-06-23T22:48:50.815 -0.001 0.000 -0.001 55829 2018-06-24T16:59:50.815 0.001 -0.000 -0.001 55852 2018-06-26T12:51:50.815 -0.001 0.000 -0.001 55868 2018-06-27T18:46:50.815 0.000 0.000 0.001 55885 2018-06-29T02:02:50.815 0.001 0.000 0.000 55908 2018-06-30T21:33:50.815 0.001 -0.000 0.001