Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue Jan 31 15:28:11 PST 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 24276 through 25455): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2011 OCT 01 00:01:06.182 2012 JAN 01 01:01:06.183 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_rec24291_24201_24291_r-v1.bsp spk_psp_rec24389_24290_24389_r-v1.bsp spk_psp_rec24479_24389_24479_r-v1.bsp spk_psp_rec24569_24478_24569_r-v1.bsp spk_psp_rec24657_24568_24657_r-v1.bsp spk_psp_rec24744_24656_24744_r-v1.bsp spk_psp_rec24822_24744_24822_r-v1.bsp spk_psp_rec24927_24821_24927_r-v1.bsp spk_psp_rec25018_24926_25018_r-v1.bsp spk_psp_rec25098_25017_25098_r-v1.bsp spk_psp_rec25189_25097_25189_r-v1.bsp spk_psp_rec25275_25187_25275_r-v1.bsp spk_psp_rec25389_25274_25389_r-v1.bsp spk_psp_rec25458_25388_25458_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_psp21.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 24290 2011-10-02T04:08:53.817 0.000 -0.000 -0.000 24312 2011-10-03T22:43:53.817 -0.000 -0.000 -0.001 24324 2011-10-04T21:03:53.817 -0.000 0.000 -0.001 24343 2011-10-06T08:38:53.817 -0.000 -0.000 -0.001 24359 2011-10-07T14:27:53.817 0.000 0.000 0.008 24376 2011-10-08T22:15:53.817 -0.000 -0.000 -0.005 24389 2011-10-09T21:33:53.817 0.000 0.000 -0.001 24406 2011-10-11T06:35:53.817 0.000 -0.000 0.000 24426 2011-10-12T19:58:53.817 -0.000 0.000 -0.001 24445 2011-10-14T06:58:53.817 0.000 0.000 -0.000 24463 2011-10-15T16:57:53.817 0.000 0.000 0.001 24478 2011-10-16T19:56:53.817 -0.000 -0.000 0.002 24496 2011-10-18T06:44:53.817 -0.000 0.000 -0.001 24514 2011-10-19T16:29:53.817 0.000 -0.000 0.001 24529 2011-10-20T20:21:53.817 -0.000 -0.000 -0.004 24551 2011-10-22T13:33:53.817 0.000 0.000 0.004 24568 2011-10-23T20:13:53.817 0.000 -0.000 -0.008 24582 2011-10-24T22:50:53.817 -0.000 0.000 -0.002 24601 2011-10-26T11:04:53.817 0.000 -0.000 0.006 24620 2011-10-27T22:43:53.817 -0.000 0.000 -0.004 24638 2011-10-29T08:13:53.817 -0.000 -0.000 -0.008 24656 2011-10-30T16:51:53.817 0.000 0.000 -0.014 24675 2011-11-01T05:28:09.817 0.000 0.000 0.004 24693 2011-11-02T14:31:53.817 -0.000 -0.000 0.001 24709 2011-11-03T21:02:53.817 -0.000 0.000 -0.004 24723 2011-11-04T23:13:53.817 0.000 -0.000 0.002 24744 2011-11-06T13:29:23.817 0.000 0.000 -0.009 24765 2011-11-08T05:48:53.817 -0.000 -0.000 -0.004 24785 2011-11-09T19:08:53.817 0.000 0.000 0.003 24804 2011-11-11T06:55:53.817 -0.000 0.000 -0.003 24821 2011-11-12T13:18:53.817 0.000 0.000 0.001 24839 2011-11-14T00:18:53.817 -0.000 -0.000 -0.004 24862 2011-11-15T19:13:53.817 0.000 -0.000 0.001 24881 2011-11-17T06:38:53.817 0.000 0.000 0.005 24899 2011-11-18T16:03:53.817 -0.000 0.000 -0.004 24913 2011-11-19T18:32:53.817 -0.000 -0.000 -0.009 24926 2011-11-20T17:43:53.817 0.000 0.000 -0.007 24945 2011-11-22T06:28:53.817 0.000 -0.000 -0.001 24964 2011-11-23T17:43:53.817 0.000 0.000 0.003 24983 2011-11-25T05:28:53.817 0.000 -0.000 0.004 25001 2011-11-26T14:20:23.817 0.000 -0.000 -0.002 25017 2011-11-27T19:57:53.817 -0.000 0.000 0.005 25036 2011-11-29T08:48:53.816 -0.000 0.000 0.001 25054 2011-11-30T17:38:53.816 -0.000 -0.000 -0.001 25076 2011-12-02T11:25:53.816 -0.000 -0.000 -0.003 25097 2011-12-04T01:36:53.816 0.000 -0.000 -0.003 25117 2011-12-05T16:04:53.816 0.000 -0.000 0.005 25137 2011-12-07T05:29:53.816 -0.000 0.000 -0.004 25153 2011-12-08T11:23:53.816 -0.000 0.000 -0.001 25170 2011-12-09T19:08:53.816 0.000 -0.000 0.002 25187 2011-12-11T02:03:53.816 -0.000 -0.000 0.004 25208 2011-12-12T18:18:53.816 -0.000 0.000 -0.003 25219 2011-12-13T14:58:53.816 0.000 0.000 0.001 25240 2011-12-15T06:08:53.816 -0.000 0.000 -0.002 25257 2011-12-16T14:02:53.816 0.000 -0.000 0.002 25274 2011-12-17T20:43:53.816 -0.000 0.000 0.001 25295 2011-12-19T12:58:53.816 0.000 -0.000 0.002 25316 2011-12-21T04:13:53.816 -0.000 -0.000 -0.003 25336 2011-12-22T17:18:53.816 0.000 -0.000 -0.000 25355 2011-12-24T05:19:53.816 0.000 -0.000 0.001 25373 2011-12-25T14:48:53.816 -0.000 -0.000 -0.001 25388 2011-12-26T17:38:53.816 -0.000 -0.000 -0.000 25407 2011-12-28T06:28:53.816 -0.000 0.000 -0.002 25425 2011-12-29T15:43:53.816 0.000 0.000 0.001 25441 2011-12-30T22:00:53.816 0.000 0.000 0.001