Mars Reconnaissance Orbiter Primary Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu May 8 11:19:37 PDT 2008 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 Primary Science Phase of the MRO mission (orbits 6707 through 7874): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2008 JAN 01 00:01:05.183 2008 APR 01 01:01:05.185 Status -------------------------------------------------------- This file was created by merging regular reconstructed OD solution SPK files produced by the MRO NAV team during the Primary 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_rec06794_06695_06794_r-v1.bsp spk_psp_rec06867_06793_06867_r-v1.bsp spk_psp_rec06968_06867_06968_r-v1.bsp spk_psp_rec07057_06968_07057_r-v1.bsp spk_psp_rec07139_07056_07139_r-v1.bsp spk_psp_rec07232_07138_07232_r-v1.bsp spk_psp_rec07309_07231_07309_r-v1.bsp spk_psp_rec07416_07309_07416_r-v1.bsp spk_psp_rec07508_07415_07508_r-v1.bsp spk_psp_rec07598_07507_07598_r-v1.bsp spk_psp_rec07681_07597_07681_r-v1.bsp spk_psp_rec07775_07680_07775_r-v1.bsp spk_psp_rec07866_07775_07866_r-v1.bsp spk_psp_rec07944_07865_07944_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_psp6.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 6713 2008-01-01T12:28:54.816 -0.000 -0.000 -0.000 6734 2008-01-03T03:53:54.816 0.001 0.000 -0.001 6753 2008-01-04T15:28:54.815 -0.001 0.000 0.000 6774 2008-01-06T06:43:54.815 -0.001 0.000 0.001 6793 2008-01-07T17:58:54.815 0.001 -0.000 -0.000 6812 2008-01-09T05:33:54.815 0.000 -0.000 -0.000 6829 2008-01-10T13:25:54.815 0.002 0.000 -0.002 6847 2008-01-11T22:58:54.815 -0.000 -0.000 0.000 6867 2008-01-13T12:23:54.815 0.000 0.000 -0.000 6885 2008-01-14T22:03:54.815 0.001 0.000 -0.001 6907 2008-01-16T15:48:54.815 -0.000 -0.000 -0.000 6928 2008-01-18T06:43:54.815 -0.001 0.000 0.000 6948 2008-01-19T20:08:54.815 0.001 -0.000 -0.000 6968 2008-01-21T09:17:54.815 -0.001 -0.000 0.000 6987 2008-01-22T20:47:54.815 0.001 0.000 -0.001 7007 2008-01-24T10:11:54.815 -0.004 -0.000 0.002 7032 2008-01-26T08:56:54.815 0.000 -0.000 -0.000 7056 2008-01-28T06:08:54.815 0.002 0.000 -0.001 7077 2008-01-29T21:03:54.815 -0.003 -0.000 0.001 7097 2008-01-31T10:28:54.815 0.003 -0.000 -0.001 7119 2008-02-02T03:35:54.815 -0.003 0.000 0.001 7138 2008-02-03T15:14:54.815 -0.000 0.000 0.000 7157 2008-02-05T02:45:54.815 0.006 0.000 -0.002 7175 2008-02-06T12:18:54.815 -0.000 0.000 0.000 7192 2008-02-07T20:33:54.815 -0.006 -0.000 0.002 7212 2008-02-09T09:58:54.815 -0.000 0.000 0.000 7231 2008-02-10T21:28:54.814 -0.002 0.000 0.001 7251 2008-02-12T10:28:54.814 0.004 -0.000 -0.001 7272 2008-02-14T01:44:54.814 -0.006 -0.000 0.001 7275 2008-02-14T07:58:54.814 -0.002 0.000 0.001 7293 2008-02-15T17:28:54.814 0.001 0.000 -0.000 7309 2008-02-16T23:23:54.814 0.008 -0.000 -0.003 7318 2008-02-17T16:13:54.814 -0.007 0.000 0.002 7336 2008-02-19T01:28:54.814 0.003 0.000 -0.000 7356 2008-02-20T14:43:54.814 -0.001 0.000 0.000 7365 2008-02-21T07:43:54.814 0.006 -0.000 -0.001 7377 2008-02-22T06:12:54.814 -0.005 0.000 0.001 7396 2008-02-23T17:43:54.814 -0.001 0.000 0.000 7415 2008-02-25T05:38:54.814 -0.001 -0.000 0.000 7434 2008-02-26T17:28:54.814 -0.002 -0.000 0.000 7456 2008-02-28T09:58:54.814 -0.003 -0.000 0.000 7470 2008-02-29T12:15:54.814 0.003 0.000 -0.001 7489 2008-03-01T23:42:54.814 0.002 -0.000 -0.000 7507 2008-03-03T09:23:54.814 0.006 0.000 -0.001 7525 2008-03-04T19:18:54.814 -0.002 -0.000 0.000 7545 2008-03-06T08:29:54.814 -0.001 -0.000 0.000 7563 2008-03-07T18:11:54.814 0.001 0.000 -0.000 7581 2008-03-09T03:50:54.814 0.004 -0.000 -0.001 7597 2008-03-10T10:03:54.814 -0.004 -0.000 0.001 7616 2008-03-11T21:38:54.814 0.004 0.000 -0.001 7639 2008-03-13T16:23:54.814 -0.001 -0.000 0.000 7659 2008-03-15T05:48:54.814 0.000 0.000 0.000 7680 2008-03-16T21:03:54.814 0.012 -0.000 -0.002 7698 2008-03-18T06:44:54.814 0.003 -0.000 -0.000 7716 2008-03-19T16:40:54.814 0.007 -0.000 -0.001 7734 2008-03-21T02:18:54.814 -0.006 0.000 0.001 7754 2008-03-22T15:48:54.814 0.000 0.000 -0.000 7775 2008-03-24T06:48:54.814 0.006 0.000 -0.001 7796 2008-03-25T22:04:54.814 -0.000 0.000 0.000 7819 2008-03-27T17:06:54.814 0.004 -0.000 -0.001 7837 2008-03-29T02:47:54.814 0.011 -0.000 -0.001 7852 2008-03-30T06:51:54.814 0.008 -0.000 -0.001 7865 2008-03-31T07:23:54.814 -0.006 0.000 0.001