Mars Reconnaissance Orbiter Primary Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Mon Aug 25 14:10:33 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 7875 through 9041): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2008 APR 01 00:01:05.185 2008 JUL 01 01:01:05.184 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_rec07944_07865_07944_r-v1.bsp spk_psp_rec08058_07943_08058_r-v1.bsp spk_psp_rec08142_08057_08142_r-v1.bsp spk_psp_rec08236_08139_08236_r-v1.bsp spk_psp_rec08307_08234_08307_r-v1.bsp spk_psp_rec08406_08306_08406_r-v1.bsp spk_psp_rec08499_08404_08499_r-v1.bsp spk_psp_rec08605_08498_08605_r-v1.bsp spk_psp_rec08684_08603_08684_r-v1.bsp spk_psp_rec08767_08684_08767_r-v1.bsp spk_psp_rec08837_08766_08837_r-v1.bsp spk_psp_rec08953_08836_08953_r-v1.bsp spk_psp_rec09043_08951_09043_r-v1.bsp spk_psp_rec09121_09041_09121_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_psp7.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 7885 2008-04-01T21:48:54.814 -0.007 0.000 -0.002 7908 2008-04-03T15:40:54.814 0.017 0.000 -0.003 7927 2008-04-05T03:13:54.814 -0.000 0.000 0.000 7943 2008-04-06T09:13:54.814 -0.009 -0.000 0.002 7963 2008-04-07T22:43:54.814 -0.005 0.000 0.001 7981 2008-04-09T08:23:54.814 0.010 -0.000 -0.002 7997 2008-04-10T15:24:54.814 0.001 0.000 0.000 8016 2008-04-12T01:40:54.814 0.006 -0.000 -0.001 8041 2008-04-14T01:08:54.814 0.005 0.000 -0.000 8057 2008-04-15T06:22:54.814 -0.012 -0.000 0.002 8074 2008-04-16T14:09:54.814 -0.006 0.000 0.001 8084 2008-04-17T08:52:54.814 0.006 -0.000 -0.001 8094 2008-04-18T03:33:54.814 0.005 0.000 -0.001 8118 2008-04-20T00:28:54.814 -0.014 0.000 0.002 8139 2008-04-21T15:43:54.814 -0.002 -0.000 0.000 8158 2008-04-23T03:08:54.814 -0.004 -0.000 0.000 8178 2008-04-24T16:42:54.814 0.006 -0.000 -0.001 8196 2008-04-26T03:34:54.814 -0.011 -0.000 -0.003 8217 2008-04-27T17:40:54.814 0.004 -0.000 -0.001 8234 2008-04-29T01:33:54.814 0.003 -0.000 -0.000 8252 2008-04-30T11:28:54.814 -0.007 0.000 0.002 8269 2008-05-01T18:48:54.814 0.010 0.000 -0.000 8285 2008-05-03T00:48:54.814 0.001 0.000 -0.000 8306 2008-05-04T16:18:54.814 0.001 0.000 -0.000 8325 2008-05-06T03:42:54.814 0.007 -0.000 -0.001 8349 2008-05-08T00:35:54.814 0.006 0.000 -0.001 8372 2008-05-09T19:37:54.814 -0.002 -0.000 0.000 8390 2008-05-11T05:17:54.814 -0.014 -0.000 0.002 8404 2008-05-12T07:30:54.814 0.009 -0.000 -0.002 8424 2008-05-13T21:57:54.814 0.009 0.000 0.002 8439 2008-05-15T00:57:54.814 -0.009 0.000 0.001 8456 2008-05-16T08:45:54.814 -0.003 -0.000 0.001 8475 2008-05-17T20:18:54.814 -0.002 -0.000 0.000 8498 2008-05-19T15:38:54.814 0.008 -0.000 -0.003 8517 2008-05-21T03:25:54.814 0.018 -0.000 -0.005 8540 2008-05-22T23:04:09.814 0.005 0.000 0.002 8564 2008-05-24T18:48:54.814 0.006 -0.000 -0.001 8587 2008-05-26T13:48:54.814 0.003 -0.000 -0.001 8603 2008-05-27T19:48:54.815 -0.005 0.000 0.001 8622 2008-05-29T07:28:54.815 0.000 -0.000 -0.000 8644 2008-05-31T00:28:54.815 -0.004 0.000 0.001 8663 2008-06-01T11:59:54.815 -0.003 -0.000 0.001 8684 2008-06-03T03:16:54.815 -0.002 0.000 0.000 8702 2008-06-04T12:58:54.815 0.008 0.000 -0.002 8725 2008-06-06T08:03:54.815 -0.006 0.000 0.002 8745 2008-06-07T21:28:54.815 0.008 -0.000 -0.002 8766 2008-06-09T12:48:54.815 0.003 0.000 -0.001 8787 2008-06-11T03:58:54.815 0.001 0.000 -0.000 8804 2008-06-12T11:46:54.815 -0.013 -0.000 0.003 8814 2008-06-13T06:38:54.815 0.003 -0.000 -0.001 8836 2008-06-14T23:39:54.815 -0.000 -0.000 0.000 8857 2008-06-16T15:03:54.815 0.009 -0.000 -0.004 8876 2008-06-18T03:03:54.815 -0.004 0.000 0.001 8898 2008-06-19T19:42:54.815 0.001 0.000 -0.000 8916 2008-06-21T05:21:54.815 0.000 0.000 -0.000 8934 2008-06-22T14:59:54.815 0.003 -0.000 -0.001 8951 2008-06-23T22:48:54.815 -0.006 0.000 0.002 8971 2008-06-25T12:16:54.815 -0.009 0.000 0.004 8986 2008-06-26T16:16:54.815 0.001 0.000 -0.000 9010 2008-06-28T13:11:54.815 -0.007 -0.000 0.003 9031 2008-06-30T04:28:54.815 -0.001 0.000 0.000 9041 2008-06-30T23:18:54.815 0.003 -0.000 -0.002