Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu Nov 8 09:49:59 PST 2012 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 27792 through 28972): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2012 JUL 01 00:01:07.184 2012 OCT 01 01:01:07.182 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_rec27804_27712_27804_r-v1.bsp spk_psp_rec27892_27802_27892_r-v1.bsp spk_psp_rec27982_27891_27982_r-v1.bsp spk_psp_rec28071_27981_28071_r-v1.bsp spk_psp_rec28153_28070_28153_r-v1.bsp spk_psp_rec28253_28150_28253_r-v1.bsp spk_psp_rec28343_28252_28343_r-v1.bsp spk_psp_rec28422_28342_28422_r-v1.bsp spk_psp_rec28521_28420_28521_r-v1.bsp spk_psp_rec28608_28519_28608_r-v1.bsp spk_psp_rec28702_28607_28702_r-v1.bsp spk_psp_rec28789_28700_28789_r-v1.bsp spk_psp_rec28879_28787_28879_r-v1.bsp spk_psp_rec28964_28877_28964_r-v1.bsp spk_psp_rec29061_28962_29061_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_psp24.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 27802 2012-07-01T19:58:52.815 -0.000 0.000 0.000 27822 2012-07-03T10:28:52.815 0.002 0.000 0.001 27840 2012-07-04T20:13:52.816 -0.001 -0.000 -0.001 27858 2012-07-06T05:48:52.816 0.004 0.000 0.001 27878 2012-07-07T18:58:52.816 0.004 -0.000 0.000 27891 2012-07-08T18:40:52.816 -0.003 0.000 0.002 27910 2012-07-10T05:36:52.816 -0.002 -0.000 -0.001 27927 2012-07-11T13:26:52.816 -0.002 0.000 -0.001 27944 2012-07-12T21:14:52.816 -0.001 -0.000 -0.000 27959 2012-07-14T01:28:52.816 -0.001 -0.000 -0.000 27981 2012-07-15T18:58:52.816 -0.004 0.000 0.002 28003 2012-07-17T11:32:37.816 0.008 0.000 0.003 28021 2012-07-18T21:11:22.816 -0.007 -0.000 -0.003 28041 2012-07-20T11:46:22.816 -0.008 -0.000 -0.000 28058 2012-07-21T18:11:52.816 0.010 0.000 0.005 28070 2012-07-22T17:19:52.816 -0.001 0.000 0.000 28088 2012-07-24T02:30:52.816 0.006 -0.000 0.002 28105 2012-07-25T11:36:52.816 -0.004 -0.000 -0.001 28118 2012-07-26T11:40:52.816 0.014 -0.000 -0.002 28136 2012-07-27T21:28:52.816 -0.007 -0.000 -0.001 28150 2012-07-28T22:54:52.816 -0.004 0.000 0.002 28170 2012-07-30T11:48:52.816 -0.008 -0.000 -0.003 28189 2012-07-31T23:33:52.816 0.003 0.000 0.000 28202 2012-08-01T23:52:52.816 -0.009 -0.000 0.000 28220 2012-08-03T09:25:52.816 -0.001 -0.000 -0.000 28238 2012-08-04T19:12:52.816 -0.004 0.000 0.000 28252 2012-08-05T22:30:37.816 0.008 0.000 0.003 28272 2012-08-07T10:30:37.816 0.009 0.000 0.004 28291 2012-08-08T23:28:52.816 0.004 0.000 0.002 28311 2012-08-10T11:23:52.816 -0.006 -0.000 -0.002 28331 2012-08-12T00:53:52.817 0.006 0.000 0.002 28342 2012-08-12T21:55:52.817 0.004 0.000 -0.001 28362 2012-08-14T11:05:52.817 0.009 0.000 -0.001 28380 2012-08-15T20:40:52.817 -0.017 0.000 -0.001 28404 2012-08-17T17:18:52.817 0.009 0.000 0.003 28420 2012-08-19T00:23:52.817 -0.009 -0.000 0.000 28439 2012-08-20T10:48:52.817 0.001 0.000 0.000 28455 2012-08-21T17:44:52.817 -0.000 0.000 0.000 28473 2012-08-23T03:44:52.817 -0.008 -0.000 -0.003 28493 2012-08-24T17:18:52.817 0.006 0.000 0.002 28510 2012-08-25T23:43:52.817 0.001 -0.000 0.000 28519 2012-08-26T17:46:22.817 0.012 -0.000 0.004 28540 2012-08-28T09:14:22.817 -0.004 -0.000 -0.002 28559 2012-08-29T19:13:52.817 -0.000 0.000 -0.000 28579 2012-08-31T08:38:52.817 -0.000 0.000 -0.000 28595 2012-09-01T14:43:52.817 -0.004 0.000 0.000 28607 2012-09-02T13:17:52.817 -0.009 0.000 0.002 28618 2012-09-03T11:00:52.817 -0.030 -0.000 -0.011 28631 2012-09-04T09:56:52.817 0.019 -0.000 0.002 28648 2012-09-05T17:40:52.817 -0.000 0.000 -0.000 28664 2012-09-06T23:28:52.817 -0.000 -0.000 -0.000 28683 2012-09-08T10:53:52.817 -0.002 -0.000 -0.001 28700 2012-09-09T19:10:52.817 0.007 0.000 -0.001 28719 2012-09-11T06:42:52.817 -0.008 0.000 0.001 28734 2012-09-12T10:45:52.817 -0.013 0.000 0.002 28747 2012-09-13T10:48:52.817 0.008 0.000 0.001 28760 2012-09-14T10:53:52.817 0.001 -0.000 0.000 28776 2012-09-15T17:03:52.817 -0.001 -0.000 -0.000 28787 2012-09-16T14:03:52.817 -0.000 0.000 0.000 28806 2012-09-18T02:08:52.817 -0.003 0.000 0.000 28828 2012-09-19T18:13:52.817 -0.002 0.000 -0.000 28845 2012-09-21T02:03:52.817 -0.002 -0.000 -0.000 28862 2012-09-22T11:03:52.817 -0.008 -0.000 -0.001 28877 2012-09-23T14:12:52.817 0.003 -0.000 -0.001 28899 2012-09-25T07:01:52.817 -0.007 -0.000 -0.001 28916 2012-09-26T16:29:52.817 0.003 0.000 0.001 28935 2012-09-28T02:14:52.817 0.002 -0.000 0.001 28952 2012-09-29T10:23:52.817 0.005 -0.000 -0.001 28962 2012-09-30T05:08:52.817 -0.005 0.000 0.001