Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Fri Apr 27 12:48:05 PDT 2012 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 25456 through 26623): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2012 JAN 01 00:01:06.183 2012 APR 01 01:01:06.185 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_rec25458_25388_25458_r-v1.bsp spk_psp_rec25546_25458_25546_r-v1.bsp spk_psp_rec25643_25545_25643_r-v1.bsp spk_psp_rec25732_25642_25732_r-v1.bsp spk_psp_rec25826_25731_25826_r-v1.bsp spk_psp_rec25915_25825_25915_r-v1.bsp spk_psp_rec25998_25914_25998_r-v1.bsp spk_psp_rec26093_25997_26093_r-v1.bsp spk_psp_rec26183_26092_26183_r-v1.bsp spk_psp_rec26261_26182_26261_r-v1.bsp spk_psp_rec26366_26260_26366_r-v1.bsp spk_psp_rec26455_26365_26455_r-v1.bsp spk_psp_rec26537_26454_26537_r-v1.bsp spk_psp_rec26636_26536_26636_r-v1.bsp spk_psp_rec26636_26558_26636_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_psp22.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 25458 2012-01-01T04:41:53.816 0.000 0.000 -0.001 25474 2012-01-02T11:42:53.816 -0.000 0.000 -0.001 25491 2012-01-03T19:29:53.816 0.000 -0.000 0.001 25510 2012-01-05T07:01:53.815 -0.000 0.000 0.000 25528 2012-01-06T16:50:53.815 -0.000 -0.000 -0.001 25545 2012-01-07T23:38:53.815 -0.000 0.000 -0.000 25565 2012-01-09T13:53:53.815 -0.000 -0.000 -0.001 25585 2012-01-11T03:16:23.815 -0.000 -0.000 -0.001 25605 2012-01-12T16:41:18.815 -0.000 -0.000 -0.001 25623 2012-01-14T02:20:53.815 0.000 -0.000 0.000 25642 2012-01-15T12:45:53.815 -0.000 -0.000 0.001 25656 2012-01-16T16:09:53.815 -0.000 -0.000 -0.001 25674 2012-01-18T01:48:53.815 -0.000 -0.000 -0.001 25693 2012-01-19T13:13:53.815 0.000 -0.000 -0.000 25713 2012-01-21T02:38:53.815 0.000 0.000 0.001 25731 2012-01-22T11:18:53.815 -0.000 -0.000 0.001 25752 2012-01-24T03:33:53.815 0.000 0.000 0.000 25769 2012-01-25T11:27:53.815 -0.000 0.000 -0.001 25792 2012-01-27T06:18:53.815 0.000 0.000 0.000 25813 2012-01-28T21:18:53.815 -0.000 0.000 -0.001 25825 2012-01-29T19:03:53.815 -0.000 0.000 0.001 25846 2012-01-31T11:18:53.815 0.000 0.000 0.000 25864 2012-02-01T20:58:53.815 -0.000 0.000 -0.001 25884 2012-02-03T10:18:53.815 0.001 -0.000 0.002 25902 2012-02-04T20:10:53.815 -0.000 0.000 -0.000 25914 2012-02-05T17:38:53.815 -0.000 -0.000 -0.000 25934 2012-02-07T07:54:53.815 0.000 -0.000 0.000 25950 2012-02-08T13:50:53.815 -0.000 -0.000 -0.001 25974 2012-02-10T10:45:53.814 -0.000 -0.000 -0.000 25997 2012-02-12T04:54:53.814 0.000 -0.000 -0.000 26016 2012-02-13T17:21:53.814 0.000 -0.000 0.001 26033 2012-02-15T01:10:53.814 -0.000 -0.000 -0.001 26052 2012-02-16T12:42:53.814 0.001 0.000 0.001 26074 2012-02-18T05:46:53.814 -0.001 -0.000 -0.001 26092 2012-02-19T14:03:53.814 0.001 0.000 -0.001 26110 2012-02-21T00:58:53.814 -0.000 0.000 -0.000 26131 2012-02-22T16:13:53.814 0.001 -0.000 0.002 26149 2012-02-24T01:53:53.814 -0.001 0.000 -0.001 26166 2012-02-25T09:55:53.814 0.002 0.000 0.002 26182 2012-02-26T14:43:53.814 -0.000 -0.000 0.000 26204 2012-02-28T08:23:53.814 0.001 -0.000 0.000 26222 2012-02-29T18:33:53.814 0.001 0.000 0.001 26241 2012-03-02T05:58:53.814 -0.001 0.000 -0.001 26260 2012-03-03T16:33:53.814 0.002 -0.000 -0.003 26281 2012-03-05T08:53:53.814 0.001 -0.000 0.001 26297 2012-03-06T14:29:53.814 0.000 -0.000 0.000 26328 2012-03-09T00:34:53.814 -0.002 -0.000 -0.001 26353 2012-03-10T23:36:53.814 0.001 0.000 0.001 26365 2012-03-11T21:16:53.814 -0.000 0.000 0.000 26386 2012-03-13T11:36:53.814 0.001 0.000 0.001 26399 2012-03-14T13:09:53.814 -0.004 0.000 -0.001 26419 2012-03-16T02:43:53.814 0.001 -0.000 0.001 26438 2012-03-17T14:38:53.814 0.003 -0.000 0.002 26454 2012-03-18T19:23:53.814 0.003 -0.000 -0.002 26475 2012-03-20T11:48:53.814 0.003 -0.000 0.002 26495 2012-03-22T01:13:53.814 0.003 0.000 0.002 26516 2012-03-23T16:28:53.814 -0.002 -0.000 -0.001 26536 2012-03-25T04:53:53.814 0.002 -0.000 -0.001 26558 2012-03-26T22:12:53.814 -0.002 0.000 0.001 26588 2012-03-29T05:20:53.814 -0.006 -0.000 -0.003 26600 2012-03-30T03:47:53.814 0.004 0.000 0.002 26619 2012-03-31T15:19:53.814 0.001 -0.000 0.000