Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu May 18 18:01:44 PDT 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 48903 through 50058): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2017 JAN 01 00:01:10.000 2017 APR 01 01:01:09.185 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_rec49005_48901_49005_r-v1.bsp spk_psp_rec49093_49002_49093_r-v1.bsp spk_psp_rec49183_49090_49183_r-v1.bsp spk_psp_rec49275_49181_49275_r-v1.bsp spk_psp_rec49364_49272_49364_r-v1.bsp spk_psp_rec49454_49362_49454_r-v1.bsp spk_psp_rec49544_49435_49544_r-v1.bsp spk_psp_rec49632_49542_49632_r-v1.bsp spk_psp_rec49722_49630_49722_r-v1.bsp spk_psp_rec49814_49719_49814_r-v1.bsp spk_psp_rec49903_49811_49903_r-v1.bsp spk_psp_rec49993_49901_49993_r-v1.bsp spk_psp_rec50080_49991_50080_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_psp42.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 48921 2017-01-02T10:50:50.816 0.003 0.000 0.002 48936 2017-01-03T13:57:50.815 -0.000 0.000 0.000 48954 2017-01-04T23:59:50.815 -0.003 0.000 0.000 48960 2017-01-05T11:05:50.815 0.001 -0.000 -0.000 48979 2017-01-06T23:33:50.815 0.001 -0.000 0.000 48990 2017-01-07T20:07:50.815 0.002 0.000 0.001 49002 2017-01-08T19:04:00.815 -0.004 0.000 0.002 49013 2017-01-09T14:33:50.815 -0.001 0.000 -0.000 49033 2017-01-11T04:10:50.815 -0.010 -0.000 -0.005 49049 2017-01-12T10:23:50.815 0.003 0.000 0.002 49069 2017-01-13T23:48:50.815 0.009 0.000 0.004 49079 2017-01-14T18:26:50.815 -0.009 0.000 -0.005 49090 2017-01-15T15:40:00.815 -0.004 -0.000 0.002 49108 2017-01-16T23:59:50.815 0.004 0.000 -0.001 49130 2017-01-18T17:52:50.815 -0.014 0.000 -0.007 49147 2017-01-20T01:39:50.815 0.004 -0.000 0.002 49159 2017-01-20T23:59:50.815 -0.003 -0.000 -0.002 49172 2017-01-21T23:58:50.815 0.004 -0.000 0.001 49181 2017-01-22T16:38:00.815 -0.005 0.000 0.000 49203 2017-01-24T10:23:50.815 -0.005 0.000 -0.003 49223 2017-01-25T23:48:50.815 -0.010 -0.000 -0.006 49238 2017-01-27T03:50:50.815 0.015 -0.000 0.008 49250 2017-01-28T02:15:50.815 -0.000 0.000 -0.000 49262 2017-01-28T23:57:50.815 -0.004 0.000 0.001 49272 2017-01-29T18:16:50.815 0.011 0.000 -0.007 49284 2017-01-30T17:52:50.815 0.010 0.000 0.006 49302 2017-02-01T03:31:50.815 0.000 -0.000 0.000 49311 2017-02-01T19:49:50.815 -0.005 0.000 -0.001 49339 2017-02-03T23:57:50.815 -0.001 0.000 0.001 49352 2017-02-04T23:57:50.815 -0.003 -0.000 0.002 49362 2017-02-05T18:30:50.815 -0.002 -0.000 0.001 49377 2017-02-06T23:44:50.815 -0.007 0.000 -0.005 49390 2017-02-07T23:57:50.815 0.008 0.000 0.005 49410 2017-02-09T13:30:50.814 0.003 -0.000 0.002 49429 2017-02-10T23:57:50.814 -0.004 -0.000 0.002 49435 2017-02-11T11:26:50.814 0.001 0.000 -0.000 49454 2017-02-12T23:47:50.814 0.002 -0.000 0.001 49463 2017-02-13T16:37:50.814 -0.002 0.000 -0.001 49474 2017-02-14T12:29:50.814 0.001 -0.000 -0.000 49489 2017-02-15T17:14:50.814 -0.002 0.000 -0.001 49506 2017-02-16T23:57:50.814 -0.004 -0.000 0.003 49518 2017-02-17T23:28:50.814 0.003 -0.000 0.002 49531 2017-02-18T23:46:50.814 -0.001 0.000 -0.001 49542 2017-02-19T19:08:50.814 0.000 -0.000 -0.000 49557 2017-02-20T23:57:50.814 0.002 -0.000 0.001 49570 2017-02-21T23:57:50.814 -0.005 0.000 0.002 49575 2017-02-22T09:22:50.814 0.008 0.000 -0.002 49595 2017-02-23T23:27:50.814 -0.001 0.000 -0.001 49608 2017-02-24T23:46:50.814 0.003 -0.000 0.002 49621 2017-02-25T23:57:50.814 0.000 -0.000 -0.000 49630 2017-02-26T15:43:50.814 0.000 -0.000 -0.000 49641 2017-02-27T13:18:50.814 0.001 0.000 0.001 49652 2017-02-28T09:18:50.814 0.000 -0.000 0.000 49672 2017-03-01T22:37:50.814 0.000 0.000 -0.000 49685 2017-03-02T23:45:50.814 -0.001 0.000 -0.001 49698 2017-03-03T23:57:50.814 -0.001 -0.000 -0.001 49708 2017-03-04T18:21:50.814 -0.002 0.000 -0.001 49719 2017-03-05T14:10:50.814 0.002 -0.000 -0.001 49732 2017-03-06T15:39:50.814 0.000 -0.000 0.000 49754 2017-03-08T08:47:50.814 0.001 0.000 0.001 49770 2017-03-09T13:56:50.814 -0.002 0.000 0.001 49786 2017-03-10T20:21:50.814 0.003 -0.000 0.002 49801 2017-03-11T23:57:50.814 -0.000 0.000 0.000 49811 2017-03-12T18:12:50.814 0.000 -0.000 -0.000 49828 2017-03-14T03:10:50.814 -0.004 -0.000 -0.003 49846 2017-03-15T12:31:50.814 -0.000 -0.000 -0.000 49857 2017-03-16T08:42:50.814 0.000 0.000 0.000 49876 2017-03-17T20:16:50.814 0.002 0.000 -0.000 49889 2017-03-18T20:17:50.814 0.001 0.000 -0.001 49901 2017-03-19T18:30:50.814 -0.001 0.000 0.001 49923 2017-03-21T12:21:50.814 0.000 -0.000 0.000 49940 2017-03-22T20:16:50.814 0.001 0.000 0.001 49951 2017-03-23T16:17:50.814 -0.000 -0.000 0.000 49967 2017-03-24T23:13:50.814 0.003 -0.000 0.002 49980 2017-03-25T23:25:50.814 -0.001 -0.000 -0.001 49991 2017-03-26T18:50:50.814 0.001 -0.000 -0.000 50009 2017-03-28T05:40:50.814 0.000 -0.000 0.000 50030 2017-03-29T20:11:50.814 -0.004 -0.000 0.002 50039 2017-03-30T13:17:50.814 0.000 0.000 -0.000 50057 2017-03-31T23:27:50.814 -0.000 0.000 0.000