Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue Feb 16 08:57:17 PST 2010 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 14907 through 16087): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2009 OCT 01 00:01:06.182 2010 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_rec15060_14965_15060_r-v1.bsp spk_psp_rec15122_15059_15122_r-v1.bsp spk_psp_rec15241_15121_15241_r-v1.bsp spk_psp_rec15338_15240_15338_r-v1.bsp spk_psp_rec15423_15337_15423_r-v1.bsp spk_psp_rec15516_15423_15516_r-v1.bsp spk_psp_rec15605_15515_15605_r-v1.bsp spk_psp_rec15692_15604_15692_r-v1.bsp spk_psp_rec15790_15690_15790_r-v1.bsp spk_psp_rec15877_15789_15877_r-v1.bsp spk_psp_rec15936_15877_15936_r-v1.bsp spk_psp_rec16009_15935_16009_r-v1.bsp spk_psp_rec16145_16009_16145_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_psp13.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 14918 2009-10-01T21:40:53.817 -0.000 0.000 -0.003 14936 2009-10-03T07:19:53.817 -0.000 -0.000 -0.002 14950 2009-10-04T09:30:53.817 0.000 0.000 -0.000 14965 2009-10-05T13:43:53.817 0.000 0.000 0.004 14984 2009-10-07T01:16:53.817 -0.000 0.000 0.001 14997 2009-10-08T01:35:53.817 0.000 -0.000 0.005 15020 2009-10-09T20:13:53.817 0.000 -0.000 0.003 15038 2009-10-11T05:52:53.817 0.000 -0.000 0.001 15059 2009-10-12T21:19:53.817 0.000 0.000 0.005 15081 2009-10-14T14:27:53.817 -0.000 0.000 -0.000 15101 2009-10-16T03:52:53.817 0.000 0.000 0.004 15121 2009-10-17T17:13:53.817 -0.000 -0.000 -0.004 15139 2009-10-19T02:48:53.817 0.000 -0.000 0.007 15154 2009-10-20T07:08:53.817 -0.000 -0.000 -0.006 15170 2009-10-21T13:04:53.817 0.000 -0.000 0.003 15188 2009-10-22T22:33:53.817 0.000 0.000 0.001 15206 2009-10-24T08:15:53.817 -0.000 -0.000 -0.003 15223 2009-10-25T16:01:53.817 0.000 0.000 0.009 15240 2009-10-26T23:48:53.817 -0.000 -0.000 -0.003 15262 2009-10-28T16:56:53.817 -0.000 0.000 -0.002 15281 2009-10-30T04:16:53.817 0.000 0.000 -0.002 15301 2009-10-31T17:48:53.817 -0.000 -0.000 -0.011 15319 2009-11-02T03:28:53.817 0.000 0.000 0.006 15337 2009-11-03T13:08:53.817 -0.000 0.000 -0.003 15354 2009-11-04T20:53:53.817 0.000 0.000 0.003 15372 2009-11-06T06:49:53.817 0.000 -0.000 0.006 15391 2009-11-07T18:20:53.817 -0.000 -0.000 -0.008 15404 2009-11-08T18:39:53.817 0.000 0.000 0.008 15423 2009-11-10T06:05:53.817 -0.000 -0.000 0.004 15438 2009-11-11T10:03:53.817 -0.000 -0.000 -0.061 15457 2009-11-12T21:35:53.817 -0.000 -0.000 0.025 15473 2009-11-14T03:31:53.817 -0.000 0.000 0.014 15493 2009-11-15T16:55:53.817 0.000 0.000 -0.003 15515 2009-11-17T10:04:53.817 0.000 0.000 -0.007 15532 2009-11-18T17:48:53.817 0.000 -0.000 -0.004 15550 2009-11-20T03:28:53.817 0.000 0.000 0.001 15571 2009-11-21T18:38:53.817 0.000 0.000 -0.002 15588 2009-11-23T02:28:53.817 -0.000 -0.000 0.003 15604 2009-11-24T08:39:53.817 -0.000 0.000 -0.002 15621 2009-11-25T16:27:53.817 -0.000 0.000 0.001 15640 2009-11-27T03:58:53.817 0.000 0.000 -0.002 15658 2009-11-28T13:30:53.816 -0.000 -0.000 0.003 15676 2009-11-29T23:09:53.816 0.000 0.000 0.001 15690 2009-12-01T01:21:53.816 0.000 -0.000 -0.002 15712 2009-12-02T18:28:53.816 0.000 0.000 -0.002 15733 2009-12-04T09:43:53.816 -0.000 -0.000 0.002 15751 2009-12-05T19:23:53.816 -0.000 0.000 0.002 15770 2009-12-07T07:31:53.816 0.000 0.000 0.000 15789 2009-12-08T19:38:53.816 -0.000 -0.000 0.006 15809 2009-12-10T07:48:53.816 -0.000 -0.000 0.001 15827 2009-12-11T17:41:53.816 0.000 -0.000 -0.002 15844 2009-12-13T01:28:53.816 -0.000 0.000 0.001 15861 2009-12-14T09:19:53.816 -0.000 -0.000 0.002 15877 2009-12-15T15:02:53.816 -0.000 0.000 0.000 15894 2009-12-16T22:50:53.816 -0.000 -0.000 -0.000 15913 2009-12-18T10:24:53.816 0.000 0.000 -0.000 15935 2009-12-20T03:32:53.816 -0.000 0.000 0.000 15954 2009-12-21T14:58:53.816 -0.000 0.000 0.000 15974 2009-12-23T04:18:53.816 0.000 -0.000 -0.001 15992 2009-12-24T14:03:53.816 0.000 0.000 -0.000 16009 2009-12-25T21:55:53.816 -0.000 0.000 0.001 16031 2009-12-27T15:10:53.816 0.000 -0.000 -0.000 16047 2009-12-28T21:30:53.816 0.000 0.000 -0.000 16068 2009-12-30T12:08:53.816 -0.000 0.000 0.000