Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu Nov 10 12:54:01 PST 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 23095 through 24275): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2011 JUL 01 00:01:06.184 2011 OCT 01 01:01:06.182 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_rec23132_23038_23132_r-v1.bsp spk_psp_rec23220_23130_23220_r-v1.bsp spk_psp_rec23302_23219_23302_r-v1.bsp spk_psp_rec23397_23302_23397_r-v1.bsp spk_psp_rec23491_23396_23491_r-v1.bsp spk_psp_rec23589_23490_23589_r-v1.bsp spk_psp_rec23670_23588_23670_r-v1.bsp spk_psp_rec23754_23670_23754_r-v1.bsp spk_psp_rec23837_23753_23837_r-v1.bsp spk_psp_rec23937_23836_23937_r-v1.bsp spk_psp_rec24025_23936_24025_r-v1.bsp spk_psp_rec24098_24024_24098_r-v1.bsp spk_psp_rec24202_24098_24202_r-v1.bsp spk_psp_rec24291_24201_24291_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_psp20.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 23113 2011-07-02T11:38:53.815 0.000 0.000 -0.000 23130 2011-07-03T19:13:53.815 -0.001 0.000 0.002 23151 2011-07-05T11:13:53.815 0.000 0.000 0.000 23171 2011-07-07T00:38:53.816 -0.000 -0.000 -0.001 23192 2011-07-08T15:23:53.816 0.000 0.000 -0.000 23208 2011-07-09T21:53:53.816 0.000 0.000 0.001 23219 2011-07-10T17:20:53.816 0.000 0.000 -0.000 23239 2011-07-12T08:09:53.816 0.000 -0.000 0.000 23260 2011-07-13T23:26:53.816 0.000 -0.000 0.000 23284 2011-07-15T20:02:53.816 0.000 0.000 0.002 23302 2011-07-17T04:33:53.816 -0.000 0.000 0.001 23322 2011-07-18T19:03:53.816 -0.000 0.000 -0.002 23342 2011-07-20T08:28:53.816 0.000 -0.000 0.002 23360 2011-07-21T17:43:53.816 0.000 0.000 0.000 23380 2011-07-23T07:33:53.816 0.000 -0.000 0.000 23396 2011-07-24T12:13:53.816 -0.000 -0.000 0.002 23414 2011-07-25T23:13:53.816 -0.000 0.000 -0.001 23437 2011-07-27T18:13:53.816 -0.000 -0.000 -0.001 23454 2011-07-29T02:15:53.816 0.000 0.000 0.000 23472 2011-07-30T11:55:53.816 -0.000 0.000 -0.000 23490 2011-07-31T20:11:53.816 0.001 0.000 -0.002 23510 2011-08-02T10:42:53.816 0.000 0.000 0.000 23528 2011-08-03T20:12:53.816 -0.000 0.000 -0.001 23546 2011-08-05T06:13:53.816 -0.000 0.000 0.000 23568 2011-08-06T22:38:53.816 -0.000 -0.000 -0.000 23588 2011-08-08T11:48:53.816 -0.000 0.000 0.001 23606 2011-08-09T22:13:53.816 -0.000 -0.000 -0.001 23624 2011-08-11T07:53:53.816 0.000 -0.000 0.000 23642 2011-08-12T17:33:53.816 0.000 -0.000 0.000 23657 2011-08-13T21:38:53.817 -0.000 -0.000 -0.002 23670 2011-08-14T20:48:53.817 0.000 -0.000 -0.002 23691 2011-08-16T13:30:53.817 0.000 -0.000 0.000 23709 2011-08-17T22:58:53.817 0.000 0.000 0.001 23732 2011-08-19T17:55:53.817 -0.000 0.000 -0.001 23753 2011-08-21T07:58:53.817 0.000 -0.000 -0.001 23773 2011-08-22T22:48:53.817 -0.000 0.000 -0.000 23796 2011-08-24T16:13:53.817 -0.000 0.000 -0.000 23816 2011-08-26T06:43:53.817 -0.000 0.000 -0.001 23836 2011-08-27T19:18:53.817 -0.000 0.000 0.000 23857 2011-08-29T11:38:53.817 0.000 -0.000 0.002 23875 2011-08-30T21:37:53.817 -0.000 0.000 -0.000 23894 2011-09-01T09:08:53.817 -0.000 -0.000 -0.000 23915 2011-09-03T00:08:53.817 -0.000 -0.000 -0.000 23936 2011-09-04T14:35:53.817 0.000 0.000 -0.002 23953 2011-09-05T23:15:53.817 0.000 0.000 0.000 23971 2011-09-07T08:53:53.817 0.000 0.000 0.001 23989 2011-09-08T18:33:53.817 -0.000 0.000 -0.001 24008 2011-09-10T06:20:53.817 0.000 -0.000 -0.000 24024 2011-09-11T10:43:53.817 0.000 -0.000 -0.002 24043 2011-09-12T23:43:53.817 0.001 -0.000 0.004 24060 2011-09-14T07:28:53.817 -0.000 -0.000 -0.003 24081 2011-09-15T21:58:53.817 0.000 0.000 -0.000 24098 2011-09-17T05:20:53.817 -0.000 -0.000 0.001 24118 2011-09-18T18:55:53.817 -0.000 0.000 0.000 24132 2011-09-19T21:18:53.817 -0.000 -0.000 0.000 24154 2011-09-21T14:38:53.817 -0.028 0.001 -0.000 24167 2011-09-22T15:23:53.817 -0.000 0.000 -0.001 24182 2011-09-23T19:28:53.817 0.000 -0.000 0.003 24201 2011-09-25T06:03:53.817 -0.000 0.000 0.001 24222 2011-09-26T21:43:53.817 -0.000 -0.000 -0.001 24239 2011-09-28T05:55:53.817 0.000 -0.000 0.005 24258 2011-09-29T17:38:53.817 -0.000 0.000 0.000 24273 2011-09-30T21:37:53.817 0.000 -0.000 0.001