Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Fri Jul 26 11:23:14 PDT 2013 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 31308 through 32475): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2013 APR 01 00:01:07.185 2013 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_rec31383_31285_31383_r-v1.bsp spk_psp_rec31635_31382_31635_r-v1.bsp spk_psp_rec31743_31634_31743_r-v1.bsp spk_psp_rec31842_31742_31842_r-v1.bsp spk_psp_rec31934_31840_31934_r-v1.bsp spk_psp_rec32024_31934_32024_r-v1.bsp spk_psp_rec32102_32024_32102_r-v1.bsp spk_psp_rec32192_32101_32192_r-v1.bsp spk_psp_rec32269_32191_32269_r-v1.bsp spk_psp_rec32379_32268_32379_r-v1.bsp spk_psp_rec32469_32378_32469_r-v1.bsp spk_psp_rec32563_32468_32563_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_psp27.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 31321 2013-04-02T02:09:52.814 -0.001 -0.001 -0.000 31333 2013-04-03T00:36:52.814 0.008 -0.002 0.000 31352 2013-04-04T11:58:52.814 0.000 -0.000 -0.000 31370 2013-04-05T21:29:52.814 0.010 -0.002 0.008 31382 2013-04-06T18:46:22.814 -0.007 -0.001 0.009 31400 2013-04-08T05:35:52.814 -0.003 -0.000 -0.007 31415 2013-04-09T09:08:52.814 -0.001 -0.002 -0.003 31430 2013-04-10T13:38:52.814 0.008 -0.001 0.008 31444 2013-04-11T15:31:52.814 0.000 -0.002 0.000 31461 2013-04-12T23:39:52.814 0.007 -0.003 -0.000 31483 2013-04-14T16:48:52.814 0.029 -0.012 0.004 31634 2013-04-26T10:08:52.814 0.006 0.004 -0.015 31653 2013-04-27T22:53:52.814 0.008 0.001 0.013 31671 2013-04-29T08:43:52.814 0.001 0.000 0.001 31688 2013-04-30T16:35:52.814 -0.003 -0.000 -0.002 31704 2013-05-01T22:30:52.814 -0.005 0.000 -0.001 31724 2013-05-03T11:18:22.814 -0.002 0.000 -0.002 31742 2013-05-04T20:06:52.814 0.002 0.000 -0.004 31756 2013-05-05T23:25:22.814 0.003 -0.000 0.004 31776 2013-05-07T12:48:52.814 0.001 -0.001 -0.000 31792 2013-05-08T18:44:52.814 0.000 0.000 0.001 31805 2013-05-09T18:54:52.814 -0.000 -0.000 -0.001 31820 2013-05-10T23:05:52.814 0.001 0.000 0.001 31840 2013-05-12T11:23:52.814 -0.000 -0.000 -0.000 31859 2013-05-14T00:03:52.814 0.000 0.000 0.002 31878 2013-05-15T11:35:52.814 0.002 -0.001 -0.001 31898 2013-05-17T00:27:52.814 -0.001 0.000 -0.000 31916 2013-05-18T10:37:52.814 -0.001 0.000 -0.001 31934 2013-05-19T19:33:52.814 -0.001 0.000 0.001 31954 2013-05-21T10:03:52.814 0.001 -0.000 -0.000 31970 2013-05-22T15:58:52.814 -0.001 -0.000 -0.000 31988 2013-05-24T00:47:52.814 0.001 0.000 0.000 32006 2013-05-25T10:56:52.814 -0.001 -0.000 -0.002 32024 2013-05-26T19:49:52.814 -0.001 -0.000 0.001 32044 2013-05-28T10:21:52.815 0.000 -0.000 -0.000 32063 2013-05-29T21:19:52.815 -0.000 -0.000 -0.001 32082 2013-05-31T09:04:52.815 0.000 0.000 0.001 32101 2013-06-01T19:28:52.815 0.000 0.000 0.000 32121 2013-06-03T09:58:52.815 -0.000 0.000 0.000 32136 2013-06-04T14:00:52.815 -0.000 0.000 -0.000 32154 2013-06-05T23:40:52.815 -0.001 0.000 -0.002 32168 2013-06-07T01:54:52.815 0.000 -0.000 0.000 32179 2013-06-07T22:29:52.815 -0.001 0.000 -0.002 32191 2013-06-08T19:46:52.815 -0.000 -0.000 0.000 32204 2013-06-09T20:18:52.815 -0.001 -0.000 0.002 32221 2013-06-11T04:38:52.815 0.002 -0.000 0.002 32241 2013-06-12T18:24:52.815 -0.000 -0.000 -0.001 32253 2013-06-13T16:49:52.815 0.000 -0.000 0.001 32268 2013-06-14T19:52:22.815 0.000 -0.000 -0.001 32284 2013-06-16T02:53:52.815 0.001 0.000 0.003 32301 2013-06-17T10:39:52.815 -0.001 -0.000 -0.002 32319 2013-06-18T20:19:52.815 0.000 -0.000 0.000 32340 2013-06-20T11:30:52.815 -0.001 -0.000 -0.002 32358 2013-06-21T21:13:52.815 -0.000 -0.000 -0.000 32378 2013-06-23T09:33:52.815 0.000 -0.000 -0.000 32393 2013-06-24T14:23:52.815 -0.000 -0.000 -0.001 32408 2013-06-25T18:08:52.815 0.001 0.000 -0.000 32428 2013-06-27T08:13:52.815 0.001 -0.000 0.001 32448 2013-06-28T21:38:52.815 0.000 0.000 0.001 32468 2013-06-30T10:18:52.815 -0.001 0.000 0.001