Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Fri Aug 12 10:06:40 PDT 2011 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 21927 through 23094): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2011 APR 01 00:01:06.185 2011 JUL 01 01:01:06.184 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_rec21963_21873_21963_r-v1.bsp spk_psp_rec22054_21962_22054_r-v1.bsp spk_psp_rec22125_22053_22125_r-v1.bsp spk_psp_rec22227_22124_22227_r-v1.bsp spk_psp_rec22309_22226_22309_r-v1.bsp spk_psp_rec22395_22308_22395_r-v1.bsp spk_psp_rec22486_22394_22486_r-v1.bsp spk_psp_rec22579_22485_22579_r-v1.bsp spk_psp_rec22682_22578_22682_r-v1.bsp spk_psp_rec22766_22680_22766_r-v1.bsp spk_psp_rec22852_22766_22852_r-v1.bsp spk_psp_rec22946_22851_22946_r-v1.bsp spk_psp_rec23039_22945_23039_r-v1.bsp spk_psp_rec23132_23038_23132_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_psp19.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 21944 2011-04-02T09:58:53.814 -0.000 -0.000 -0.000 21962 2011-04-03T18:28:53.814 0.002 0.000 -0.003 21982 2011-04-05T09:08:53.814 0.003 -0.001 0.002 22001 2011-04-06T20:43:53.814 -0.000 0.000 -0.000 22022 2011-04-08T11:38:53.814 -0.000 -0.000 -0.000 22041 2011-04-09T23:18:53.814 0.000 0.000 0.000 22053 2011-04-10T20:54:53.814 -0.001 -0.000 0.001 22076 2011-04-12T16:47:53.814 0.001 0.000 0.001 22092 2011-04-13T22:43:53.814 -0.000 -0.000 -0.000 22110 2011-04-15T08:42:53.814 0.000 0.000 0.000 22124 2011-04-16T09:25:53.814 0.000 -0.000 -0.001 22144 2011-04-17T23:50:53.814 -0.001 0.000 -0.003 22169 2011-04-19T22:45:53.814 -0.000 -0.000 -0.001 22192 2011-04-21T17:58:53.814 0.001 -0.000 0.001 22208 2011-04-22T23:48:53.814 -0.000 0.000 0.000 22226 2011-04-24T08:18:53.814 0.001 0.000 -0.001 22248 2011-04-26T02:28:53.814 -0.001 -0.000 -0.002 22269 2011-04-27T17:48:53.814 -0.001 -0.000 -0.002 22291 2011-04-29T10:54:53.814 0.002 -0.000 0.004 22308 2011-04-30T17:54:53.814 -0.001 0.000 0.002 22331 2011-05-02T13:28:53.814 0.000 0.000 0.001 22358 2011-05-04T16:14:53.814 0.001 0.000 0.002 22376 2011-05-06T02:08:53.814 -0.000 -0.000 -0.000 22394 2011-05-07T10:25:53.814 -0.001 -0.000 0.002 22407 2011-05-08T11:58:53.814 -0.001 -0.000 -0.002 22424 2011-05-09T19:57:53.814 -0.001 0.000 -0.000 22444 2011-05-11T09:21:53.814 -0.000 0.000 -0.000 22464 2011-05-12T22:28:53.814 0.000 -0.000 0.001 22485 2011-05-14T12:38:53.814 -0.000 0.000 0.001 22508 2011-05-16T08:45:53.814 -0.000 -0.000 -0.000 22527 2011-05-17T20:16:53.814 0.001 -0.000 0.002 22551 2011-05-19T17:10:53.814 -0.000 0.001 0.001 22567 2011-05-20T23:22:53.814 -0.001 -0.000 -0.000 22578 2011-05-21T18:48:53.814 0.000 -0.000 -0.001 22603 2011-05-23T18:42:53.814 -0.001 0.000 -0.000 22619 2011-05-24T23:40:53.814 0.000 -0.000 -0.000 22644 2011-05-26T23:04:53.814 -0.001 -0.000 -0.001 22666 2011-05-28T16:13:53.815 -0.000 0.000 -0.001 22680 2011-05-29T17:48:53.815 0.000 0.000 0.000 22701 2011-05-31T09:41:23.815 0.000 -0.000 -0.000 22717 2011-06-01T15:33:53.815 0.000 0.000 -0.000 22739 2011-06-03T08:43:53.815 0.000 -0.000 0.001 22755 2011-06-04T14:41:53.815 0.001 0.000 0.003 22766 2011-06-05T10:10:53.815 -0.001 -0.000 0.004 22785 2011-06-06T23:06:53.815 0.000 -0.000 0.000 22803 2011-06-08T08:46:53.815 -0.000 -0.000 -0.001 22830 2011-06-10T10:58:53.815 0.001 -0.000 0.002 22851 2011-06-12T01:48:53.815 0.000 -0.000 0.000 22872 2011-06-13T17:43:53.815 0.001 -0.000 0.002 22888 2011-06-14T23:43:53.815 0.000 0.000 0.000 22909 2011-06-16T14:43:53.815 0.000 -0.000 0.000 22926 2011-06-17T22:23:53.815 -0.000 -0.000 -0.001 22945 2011-06-19T08:56:53.815 -0.000 -0.000 0.000 22964 2011-06-20T21:34:53.815 -0.000 0.000 -0.000 22983 2011-06-22T09:06:53.815 0.000 -0.000 -0.000 23002 2011-06-23T20:38:53.815 0.000 0.000 0.000 23020 2011-06-25T06:40:53.815 0.000 -0.000 -0.000 23038 2011-06-26T14:50:53.815 -0.000 0.000 0.001 23054 2011-06-27T21:54:53.815 0.000 -0.000 0.000 23073 2011-06-29T09:26:53.815 0.000 -0.000 0.001 23092 2011-06-30T21:03:53.815 0.000 -0.000 0.000