Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Mon Jan 30 12:56:00 PST 2017 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 47723 through 48902): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2016 OCT 01 00:01:09.000 2017 JAN 01 01:01:09.183 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_rec47741_47653_47741_r-v1.bsp spk_psp_rec47832_47739_47832_r-v1.bsp spk_psp_rec47925_47830_47925_r-v1.bsp spk_psp_rec48015_47923_48015_r-v1.bsp spk_psp_rec48100_48012_48100_r-v1.bsp spk_psp_rec48197_48097_48197_r-v1.bsp spk_psp_rec48274_48194_48274_r-v1.bsp spk_psp_rec48374_48271_48374_r-v1.bsp spk_psp_rec48460_48373_48460_r-v1.bsp spk_psp_rec48554_48457_48554_r-v1.bsp spk_psp_rec48644_48551_48644_r-v1.bsp spk_psp_rec48723_48640_48723_r-v1.bsp spk_psp_rec48825_48720_48825_r-v1.bsp spk_psp_rec48902_48822_48902_r-v1.bsp spk_psp_rec49005_48901_49005_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_psp41.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 47739 2016-10-02T07:52:00.817 -0.052 0.000 0.000 47760 2016-10-03T23:30:51.817 -0.007 0.000 0.000 47771 2016-10-04T20:06:51.817 0.030 0.000 -0.000 47780 2016-10-05T12:58:51.817 0.045 0.000 -0.001 47793 2016-10-06T13:17:51.817 0.027 0.000 -0.000 47811 2016-10-07T22:58:51.817 -0.010 0.001 0.000 47819 2016-10-08T13:35:51.817 -0.001 0.001 -0.000 47830 2016-10-09T09:44:00.817 0.067 0.000 0.002 47843 2016-10-10T10:33:51.817 -0.004 -0.001 -0.000 47857 2016-10-11T12:27:51.817 0.005 0.001 0.000 47870 2016-10-12T12:41:51.817 -0.068 0.001 -0.003 47883 2016-10-13T13:01:51.817 0.065 0.000 0.003 47900 2016-10-14T20:38:51.817 -0.027 0.001 -0.001 47912 2016-10-15T19:19:51.817 -0.061 0.000 -0.004 47923 2016-10-16T15:27:00.817 0.076 0.001 -0.002 47934 2016-10-17T12:30:51.817 -0.055 0.000 -0.004 47951 2016-10-18T20:19:51.817 -0.007 -0.000 -0.001 47966 2016-10-19T23:58:51.817 -0.028 -0.001 0.000 47973 2016-10-20T13:19:51.817 0.016 -0.000 0.001 47990 2016-10-21T20:36:51.817 0.049 0.000 -0.004 47998 2016-10-22T12:30:51.817 -0.055 0.001 -0.005 48012 2016-10-23T15:14:00.817 0.023 0.000 -0.002 48030 2016-10-24T23:59:51.817 0.000 0.000 -0.000 48050 2016-10-26T13:14:51.817 0.026 -0.000 0.001 48063 2016-10-27T13:09:51.817 0.004 -0.000 -0.000 48083 2016-10-29T03:35:51.817 0.000 0.000 0.000 48097 2016-10-30T05:08:00.817 -0.005 -0.000 -0.000 48114 2016-10-31T13:10:51.817 0.012 -0.000 0.002 48131 2016-11-01T20:34:51.817 -0.007 -0.000 0.000 48144 2016-11-02T20:33:51.817 0.047 0.001 -0.008 48152 2016-11-03T11:33:51.817 -0.014 -0.000 0.002 48171 2016-11-04T23:59:51.817 0.006 -0.000 0.001 48184 2016-11-05T23:58:51.817 -0.040 0.000 -0.004 48194 2016-11-06T18:38:00.817 0.042 -0.000 0.003 48204 2016-11-07T13:03:51.817 0.016 -0.000 -0.002 48216 2016-11-08T12:58:51.817 0.012 0.000 -0.002 48235 2016-11-09T23:54:51.817 0.003 0.000 0.000 48248 2016-11-10T23:58:51.817 0.011 -0.000 0.002 48255 2016-11-11T12:53:51.817 -0.010 -0.000 -0.002 48271 2016-11-12T18:59:00.817 0.023 -0.000 0.005 48293 2016-11-14T12:48:51.817 0.014 0.000 -0.002 48306 2016-11-15T12:18:51.817 -0.008 -0.000 -0.002 48315 2016-11-16T04:23:51.817 -0.005 0.000 0.001 48331 2016-11-17T10:37:51.817 0.019 -0.000 -0.003 48349 2016-11-18T20:33:51.817 0.000 0.000 0.000 48364 2016-11-19T23:59:51.817 -0.030 -0.000 0.008 48373 2016-11-20T17:06:00.817 0.014 -0.000 -0.003 48391 2016-11-22T04:14:51.817 -0.009 -0.000 0.002 48408 2016-11-23T12:07:51.817 -0.005 -0.000 0.001 48417 2016-11-24T04:11:51.817 0.010 0.000 0.003 48440 2016-11-25T23:24:51.817 -0.001 -0.000 -0.000 48451 2016-11-26T20:00:21.817 -0.010 -0.000 -0.002 48457 2016-11-27T06:57:00.817 0.004 0.000 0.001 48473 2016-11-28T12:12:51.816 0.000 0.000 -0.000 48485 2016-11-29T11:36:51.816 0.022 0.000 0.004 48505 2016-11-30T23:58:51.816 -0.006 -0.000 0.002 48528 2016-12-02T20:02:51.816 -0.012 0.000 -0.002 48543 2016-12-03T23:58:51.816 0.018 -0.000 0.005 48551 2016-12-04T15:25:00.816 0.010 -0.000 -0.002 48569 2016-12-05T23:47:51.816 0.004 -0.000 -0.001 48579 2016-12-06T18:26:51.816 -0.002 -0.000 0.001 48588 2016-12-07T12:02:51.816 0.000 0.000 0.000 48603 2016-12-08T16:09:51.816 -0.014 0.000 -0.005 48620 2016-12-09T23:59:51.816 -0.005 -0.000 -0.002 48633 2016-12-10T23:58:51.816 0.005 -0.000 0.002 48640 2016-12-11T13:52:00.816 -0.001 0.000 0.000 48656 2016-12-12T18:16:51.816 -0.002 0.000 0.001 48670 2016-12-13T20:36:51.816 0.013 0.000 -0.005 48686 2016-12-15T03:19:21.816 -0.009 0.000 -0.004 48708 2016-12-16T20:40:21.816 0.004 0.000 0.001 48720 2016-12-17T19:32:00.816 0.003 -0.000 -0.001 48742 2016-12-19T11:46:51.816 -0.009 0.000 -0.003 48758 2016-12-20T18:11:51.816 -0.003 0.000 -0.001 48776 2016-12-22T03:52:51.816 0.003 0.000 0.001 48787 2016-12-23T00:30:51.816 0.007 0.000 0.002 48802 2016-12-24T04:16:51.816 -0.008 -0.000 -0.004 48822 2016-12-25T18:24:00.816 -0.004 -0.000 0.002 48844 2016-12-27T11:30:51.816 0.006 0.000 -0.002 48857 2016-12-28T11:24:51.816 0.001 0.000 0.000 48875 2016-12-29T20:36:51.816 -0.010 -0.000 -0.004 48888 2016-12-30T20:35:51.816 0.011 -0.000 -0.001 48901 2016-12-31T20:25:00.816 0.003 -0.000 -0.001