Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu Aug 11 12:49:21 PDT 2016 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 45375 through 46541): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2016 APR 01 00:01:09.000 2016 JUL 01 01:01:08.184 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_rec45402_45313_45402_r-v1.bsp spk_psp_rec45496_45400_45496_r-v1.bsp spk_psp_rec45585_45494_45585_r-v1.bsp spk_psp_rec45672_45583_45672_r-v1.bsp spk_psp_rec45765_45670_45765_r-v1.bsp spk_psp_rec45851_45762_45851_r-v1.bsp spk_psp_rec45946_45849_45946_r-v1.bsp spk_psp_rec46034_45944_46034_r-v1.bsp spk_psp_rec46128_46031_46128_r-v1.bsp spk_psp_rec46219_46125_46219_r-v1.bsp spk_psp_rec46310_46217_46310_r-v1.bsp spk_psp_rec46394_46308_46394_r-v1.bsp spk_psp_rec46490_46391_46490_r-v1.bsp spk_psp_rec46567_46487_46567_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_psp39.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 45387 2016-04-02T01:40:51.814 0.000 0.000 0.001 45400 2016-04-03T00:56:00.814 0.000 0.000 -0.000 45420 2016-04-04T15:08:51.814 0.000 0.000 0.000 45434 2016-04-05T17:32:51.814 0.002 -0.000 0.005 45449 2016-04-06T21:36:51.814 0.001 -0.000 0.002 45457 2016-04-07T12:33:51.814 -0.001 0.000 -0.002 45476 2016-04-08T23:20:51.814 0.000 0.000 -0.001 45494 2016-04-10T08:43:00.814 -0.001 -0.000 0.002 45509 2016-04-11T13:48:51.814 -0.000 0.000 -0.001 45521 2016-04-12T12:15:51.814 -0.001 0.000 -0.001 45535 2016-04-13T14:26:51.814 0.001 0.000 0.001 45547 2016-04-14T12:53:51.814 -0.001 -0.000 -0.001 45565 2016-04-15T22:33:51.814 0.000 -0.000 0.001 45583 2016-04-17T07:10:00.814 0.001 0.000 -0.001 45599 2016-04-18T14:09:51.814 0.001 0.000 0.001 45611 2016-04-19T12:35:51.814 -0.001 -0.000 -0.002 45629 2016-04-20T21:40:51.814 -0.000 0.000 0.000 45637 2016-04-21T13:13:51.814 0.001 -0.000 0.001 45655 2016-04-22T22:29:51.814 0.000 -0.000 0.000 45670 2016-04-24T02:18:00.814 0.000 0.000 -0.000 45689 2016-04-25T13:44:51.814 0.001 0.000 -0.001 45701 2016-04-26T12:55:51.814 0.000 0.000 0.000 45711 2016-04-27T07:38:51.814 -0.001 -0.000 -0.001 45731 2016-04-28T21:02:51.814 0.002 -0.000 0.003 45752 2016-04-30T12:19:51.814 -0.001 -0.000 -0.001 45762 2016-05-01T05:57:00.814 -0.001 -0.000 0.002 45779 2016-05-02T14:49:51.814 -0.000 0.000 -0.000 45786 2016-05-03T03:55:51.814 -0.001 -0.000 -0.002 45806 2016-05-04T17:20:51.814 0.002 0.000 0.003 45816 2016-05-05T12:02:51.814 -0.001 -0.000 -0.002 45837 2016-05-07T03:19:51.814 -0.001 0.000 -0.001 45849 2016-05-08T00:40:00.814 0.001 -0.000 -0.001 45868 2016-05-09T12:38:51.814 -0.002 0.000 0.001 45875 2016-05-10T02:23:51.814 0.002 -0.000 0.003 45895 2016-05-11T15:13:51.814 -0.001 0.000 0.000 45906 2016-05-12T12:22:51.814 0.003 -0.000 0.003 45923 2016-05-13T20:09:51.814 -0.002 -0.000 -0.002 45927 2016-05-14T03:25:51.814 -0.001 0.000 -0.001 45944 2016-05-15T10:21:00.814 -0.001 0.000 0.001 45958 2016-05-16T13:03:51.814 -0.002 0.000 0.000 45970 2016-05-17T11:53:51.814 0.004 0.000 0.004 45982 2016-05-18T09:55:51.814 -0.002 0.000 0.000 45998 2016-05-19T16:08:51.814 0.002 0.000 0.001 46013 2016-05-20T20:08:51.814 -0.002 0.000 -0.001 46022 2016-05-21T12:55:51.814 0.003 -0.000 0.001 46031 2016-05-22T05:04:00.814 -0.004 0.000 0.003 46048 2016-05-23T13:48:51.814 -0.003 -0.000 -0.003 46063 2016-05-24T18:04:51.814 0.002 0.000 0.002 46072 2016-05-25T10:55:51.814 -0.005 0.000 -0.003 46085 2016-05-26T11:08:51.814 0.002 0.000 0.002 46099 2016-05-27T13:00:51.815 -0.003 0.000 -0.001 46113 2016-05-28T15:03:51.815 0.005 -0.000 0.001 46125 2016-05-29T13:32:00.815 -0.007 0.000 -0.001 46138 2016-05-30T14:23:51.815 -0.003 -0.000 -0.002 46156 2016-05-31T23:58:51.815 0.004 -0.000 0.003 46166 2016-06-01T18:45:51.815 -0.002 -0.000 -0.001 46178 2016-06-02T16:38:51.815 0.004 -0.000 0.001 46195 2016-06-03T23:59:51.815 -0.003 0.000 0.002 46199 2016-06-04T08:30:51.815 0.006 0.000 0.003 46217 2016-06-05T16:55:00.815 -0.005 -0.000 0.003 46233 2016-06-06T23:58:51.815 -0.005 -0.000 -0.003 46250 2016-06-08T07:56:51.815 0.000 0.000 0.000 46265 2016-06-09T11:59:51.815 0.003 0.000 0.001 46284 2016-06-10T23:32:51.815 -0.009 -0.000 -0.004 46297 2016-06-11T23:52:51.815 0.005 0.000 0.002 46308 2016-06-12T19:07:00.815 -0.005 -0.000 0.002 46318 2016-06-13T14:53:51.815 -0.002 0.000 -0.001 46336 2016-06-14T23:58:51.815 0.005 -0.000 -0.001 46353 2016-06-16T08:38:51.815 0.000 -0.000 0.000 46374 2016-06-17T23:56:51.815 -0.002 -0.000 -0.001 46391 2016-06-19T06:20:00.815 -0.000 0.000 0.000 46413 2016-06-20T23:59:51.815 -0.003 0.000 0.001 46421 2016-06-21T13:59:51.815 0.002 0.000 0.001 46439 2016-06-22T23:41:51.815 -0.011 -0.000 -0.003 46456 2016-06-24T08:44:51.815 -0.001 0.000 -0.000 46477 2016-06-25T23:59:51.815 0.012 -0.000 0.001 46487 2016-06-26T17:55:00.815 -0.008 -0.000 0.003 46503 2016-06-27T23:24:51.815 0.001 -0.000 0.000 46525 2016-06-29T16:36:51.815 -0.000 -0.000 -0.000 46535 2016-06-30T11:19:51.815 0.005 0.000 0.001