Mars Reconnaissance Orbiter Primary Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Mon Dec 1 08:31:56 PST 2008 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 Primary Science Phase of the MRO mission (orbits 9042 through 10222): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2008 JUL 01 00:01:05.184 2008 OCT 01 01:01:05.182 Status -------------------------------------------------------- This file was created by merging regular reconstructed OD solution SPK files produced by the MRO NAV team during the Primary 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_rec09043_08951_09043_r-v1.bsp spk_psp_rec09121_09041_09121_r-v1.bsp spk_psp_rec09225_09119_09225_r-v1.bsp spk_psp_rec09307_09224_09307_r-v1.bsp spk_psp_rec09402_09306_09402_r-v1.bsp spk_psp_rec09491_09400_09491_r-v1.bsp spk_psp_rec09568_09490_09568_r-v1.bsp spk_psp_rec09675_09566_09675_r-v1.bsp spk_psp_rec09760_09674_09760_r-v1.bsp spk_psp_rec09844_09758_09844_r-v1.bsp spk_psp_rec09939_09843_09939_r-v1.bsp spk_psp_rec10029_09938_10029_r-v1.bsp spk_psp_rec10114_10027_10114_r-v1.bsp spk_psp_rec10208_10113_10208_r-v1.bsp spk_psp_rec10294_10207_10294_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_psp8.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 9056 2008-07-02T03:58:54.815 0.004 0.000 0.001 9077 2008-07-03T18:28:54.815 0.003 -0.000 -0.001 9100 2008-07-05T13:30:54.816 -0.004 0.000 0.002 9119 2008-07-07T01:08:54.816 0.002 -0.000 -0.001 9140 2008-07-08T16:21:54.816 0.010 -0.000 -0.005 9159 2008-07-10T04:28:54.816 -0.008 0.000 0.001 9177 2008-07-11T13:28:54.816 0.007 -0.000 -0.003 9201 2008-07-13T10:23:54.816 0.004 -0.000 -0.002 9224 2008-07-15T05:23:54.816 0.007 0.000 -0.003 9242 2008-07-16T15:01:54.816 0.008 -0.000 -0.003 9265 2008-07-18T10:18:54.816 -0.001 -0.000 0.001 9286 2008-07-20T01:58:54.816 0.007 0.000 -0.001 9306 2008-07-21T14:53:54.816 -0.003 -0.000 0.002 9327 2008-07-23T06:03:54.816 0.007 -0.000 -0.004 9342 2008-07-24T10:05:54.816 -0.004 -0.000 0.002 9353 2008-07-25T06:49:54.816 0.003 -0.000 -0.002 9372 2008-07-26T18:18:54.816 0.000 -0.000 -0.000 9388 2008-07-28T00:19:54.816 0.008 -0.000 -0.005 9400 2008-07-28T22:26:54.816 -0.000 -0.000 0.000 9422 2008-07-30T15:39:54.816 0.005 -0.000 -0.002 9438 2008-07-31T21:38:54.816 0.001 0.000 -0.001 9459 2008-08-02T12:52:54.816 0.001 0.000 -0.000 9479 2008-08-04T02:10:54.816 -0.005 0.000 0.001 9490 2008-08-04T22:51:54.816 0.002 0.000 -0.001 9512 2008-08-06T15:59:54.816 -0.004 0.000 0.002 9529 2008-08-07T23:47:54.816 0.005 -0.000 -0.003 9550 2008-08-09T15:03:54.816 -0.000 0.000 0.000 9566 2008-08-10T21:00:54.816 -0.001 -0.000 0.000 9584 2008-08-12T06:33:54.817 0.001 0.000 -0.000 9604 2008-08-13T20:03:54.817 0.001 -0.000 -0.001 9622 2008-08-15T05:43:54.817 -0.000 0.000 0.000 9641 2008-08-16T17:15:54.817 0.004 -0.000 -0.002 9657 2008-08-17T23:08:54.817 -0.006 0.000 0.003 9674 2008-08-19T06:57:54.817 -0.001 -0.000 0.001 9692 2008-08-20T16:37:54.817 0.004 -0.000 -0.002 9710 2008-08-22T02:53:54.817 -0.003 -0.000 0.000 9729 2008-08-23T14:10:54.817 0.001 -0.000 -0.000 9750 2008-08-25T05:06:54.817 -0.007 0.000 0.004 9758 2008-08-25T20:03:54.817 0.003 -0.000 -0.002 9779 2008-08-27T11:21:14.817 -0.003 0.000 0.002 9797 2008-08-28T20:58:54.817 0.002 0.000 -0.001 9819 2008-08-30T14:13:54.817 0.004 -0.000 -0.003 9843 2008-09-01T10:59:54.817 0.001 0.000 -0.000 9863 2008-09-03T00:25:54.817 0.007 0.000 -0.004 9882 2008-09-04T11:57:54.817 -0.005 -0.000 0.003 9900 2008-09-05T21:22:54.817 0.003 0.000 -0.001 9919 2008-09-07T09:29:54.817 -0.003 0.000 0.002 9938 2008-09-08T20:37:54.817 -0.002 -0.000 0.001 9955 2008-09-10T04:17:54.817 -0.001 -0.000 0.000 9978 2008-09-11T23:23:54.817 -0.002 0.000 0.001 9997 2008-09-13T10:57:54.817 -0.000 0.000 0.000 10016 2008-09-14T22:30:54.817 0.001 -0.000 -0.000 10027 2008-09-15T19:08:54.817 -0.000 -0.000 0.000 10048 2008-09-17T10:23:54.817 -0.002 -0.000 0.001 10069 2008-09-19T01:58:54.817 0.002 0.000 -0.001 10091 2008-09-20T19:13:54.817 0.004 0.000 -0.001 10113 2008-09-22T11:57:54.817 0.005 0.000 -0.003 10126 2008-09-23T12:13:54.817 0.006 0.000 -0.004 10145 2008-09-24T23:45:54.817 -0.001 0.000 0.000 10164 2008-09-26T11:18:54.817 0.002 0.000 -0.002 10181 2008-09-27T19:04:54.817 0.001 0.000 -0.000 10199 2008-09-29T04:43:54.817 0.001 -0.000 -0.001 10207 2008-09-29T19:40:54.817 -0.002 0.000 0.001 10213 2008-09-30T06:56:54.817 0.004 -0.000 -0.002