Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Sun Jul 29 09:54:45 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 26624 through 27791): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2012 APR 01 00:01:06.185 2012 JUL 01 01:01:07.184 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_rec26636_26558_26636_r-v1.bsp spk_psp_rec26726_26634_26726_r-v1.bsp spk_psp_rec26804_26724_26804_r-v1.bsp spk_psp_rec26899_26802_26899_r-v1.bsp spk_psp_rec26996_26897_26996_r-v1.bsp spk_psp_rec27085_26995_27085_r-v1.bsp spk_psp_rec27174_27083_27174_r-v1.bsp spk_psp_rec27265_27172_27265_r-v1.bsp spk_psp_rec27353_27263_27353_r-v1.bsp spk_psp_rec27423_27352_27423_r-v1.bsp spk_psp_rec27521_27422_27521_r-v1.bsp spk_psp_rec27618_27519_27618_r-v1.bsp spk_psp_rec27714_27616_27714_r-v1.bsp spk_psp_rec27804_27712_27804_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_psp23.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 26634 2012-04-01T20:30:53.814 -0.003 0.000 0.000 26655 2012-04-03T10:46:53.814 0.001 -0.000 0.000 26675 2012-04-05T00:11:53.814 0.004 0.000 0.001 26688 2012-04-06T00:30:53.814 -0.003 -0.000 -0.001 26706 2012-04-07T11:52:23.814 -0.006 -0.000 -0.003 26724 2012-04-08T20:03:53.814 0.001 0.000 -0.000 26743 2012-04-10T08:38:53.814 0.002 -0.000 0.001 26764 2012-04-11T22:53:53.814 -0.002 0.000 0.000 26783 2012-04-13T10:06:23.814 -0.003 -0.000 -0.001 26802 2012-04-14T22:13:53.814 0.004 -0.000 -0.002 26823 2012-04-16T14:38:53.814 0.001 0.000 0.000 26843 2012-04-18T02:13:53.814 0.016 0.000 0.007 26860 2012-04-19T10:15:53.814 -0.013 -0.000 -0.002 26879 2012-04-20T21:41:53.814 0.007 -0.000 0.002 26897 2012-04-22T08:33:53.814 -0.015 0.000 -0.001 26918 2012-04-23T22:38:53.814 -0.023 -0.000 -0.007 26937 2012-04-25T10:11:53.814 0.011 0.000 0.003 26958 2012-04-27T01:28:53.814 0.007 0.000 0.002 26977 2012-04-28T14:28:53.814 -0.001 -0.000 -0.001 26995 2012-04-29T23:13:53.814 0.010 -0.000 -0.005 27018 2012-05-01T17:38:53.814 0.007 -0.000 0.002 27038 2012-05-03T07:02:23.814 0.000 -0.000 -0.000 27058 2012-05-04T20:28:53.814 -0.002 -0.000 -0.001 27070 2012-05-05T18:54:53.814 -0.003 -0.000 -0.001 27083 2012-05-06T19:53:53.814 -0.002 -0.000 0.001 27102 2012-05-08T06:53:53.814 -0.001 0.000 -0.000 27117 2012-05-09T12:18:53.814 0.008 0.000 0.004 27137 2012-05-11T00:13:53.814 -0.000 0.000 -0.000 27156 2012-05-12T11:43:53.814 0.007 -0.000 0.003 27172 2012-05-13T18:09:53.814 -0.002 -0.000 0.001 27191 2012-05-15T05:20:53.814 0.000 -0.000 0.000 27207 2012-05-16T12:20:53.814 -0.007 0.000 -0.001 27227 2012-05-18T00:28:53.814 -0.002 -0.000 -0.001 27246 2012-05-19T13:28:53.814 -0.000 0.000 -0.000 27263 2012-05-20T20:23:53.814 -0.006 0.000 0.003 27284 2012-05-22T12:08:53.814 0.003 0.000 -0.000 27299 2012-05-23T16:38:53.814 -0.014 -0.000 -0.006 27316 2012-05-25T00:20:08.814 0.009 0.000 0.003 27335 2012-05-26T11:49:53.814 0.002 0.000 0.001 27352 2012-05-27T18:49:23.815 0.008 -0.000 -0.004 27373 2012-05-29T09:31:23.815 0.004 0.000 0.002 27387 2012-05-30T11:33:53.815 -0.008 -0.000 -0.004 27405 2012-05-31T22:43:53.815 0.005 0.000 0.002 27422 2012-06-02T05:28:53.815 -0.003 0.000 0.000 27442 2012-06-03T18:43:53.815 -0.004 0.000 -0.000 27463 2012-06-05T09:43:53.815 0.002 0.000 0.001 27482 2012-06-06T22:18:53.815 0.010 0.000 -0.004 27501 2012-06-08T09:58:53.815 -0.006 0.000 0.001 27519 2012-06-09T19:04:53.815 0.006 -0.000 -0.003 27540 2012-06-11T09:58:53.815 -0.001 -0.000 -0.000 27559 2012-06-12T21:29:53.815 0.002 0.000 0.000 27577 2012-06-14T06:48:53.815 0.001 0.000 0.000 27598 2012-06-15T22:43:53.815 -0.015 0.000 0.006 27616 2012-06-17T08:33:53.815 0.008 -0.000 -0.004 27638 2012-06-19T01:03:53.815 0.010 0.000 0.004 27656 2012-06-20T12:18:53.815 -0.003 -0.000 -0.002 27678 2012-06-22T03:48:53.815 0.005 0.000 0.002 27695 2012-06-23T11:48:53.815 0.011 0.000 0.001 27712 2012-06-24T20:13:53.815 -0.017 0.000 0.009 27732 2012-06-26T09:48:53.815 -0.004 0.000 0.001 27750 2012-06-27T18:25:53.815 -0.005 -0.000 -0.002 27769 2012-06-29T06:06:53.815 0.002 0.000 0.000 27788 2012-06-30T17:35:53.815 -0.003 -0.000 -0.001