Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu May 8 15:39:06 PDT 2014 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 34837 through 35991): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2014 JAN 01 00:01:07.183 2014 APR 01 01:01:07.185 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_rec34887_34803_34887_r-v1.bsp spk_psp_rec34981_34886_34981_r-v1.bsp spk_psp_rec35076_34979_35076_r-v1.bsp spk_psp_rec35170_35075_35170_r-v1.bsp spk_psp_rec35255_35169_35255_r-v1.bsp spk_psp_rec35349_35254_35349_r-v1.bsp spk_psp_rec35439_35348_35439_r-v1.bsp spk_psp_rec35518_35438_35518_r-v1.bsp spk_psp_rec35604_35517_35604_r-v1.bsp spk_psp_rec35705_35602_35705_r-v1.bsp spk_psp_rec35797_35705_35797_r-v1.bsp spk_psp_rec35887_35796_35887_r-v1.bsp spk_psp_rec35976_35886_35976_r-v1.bsp spk_psp_rec36068_35975_36068_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_psp30.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 34852 2014-01-02T05:41:52.816 -0.000 0.000 -0.002 34870 2014-01-03T15:22:52.816 0.000 -0.000 0.001 34886 2014-01-04T20:10:52.815 0.000 0.000 -0.001 34899 2014-01-05T21:36:52.815 0.000 -0.000 0.001 34920 2014-01-07T12:50:52.815 -0.000 0.000 0.000 34942 2014-01-09T05:58:52.815 0.000 0.000 0.001 34964 2014-01-10T22:53:52.815 -0.000 -0.000 -0.002 34979 2014-01-12T01:57:52.815 0.000 -0.000 -0.002 35003 2014-01-14T00:13:52.815 -0.000 -0.000 -0.001 35024 2014-01-15T15:33:52.815 -0.000 0.000 0.000 35041 2014-01-16T23:07:52.815 0.000 0.000 0.002 35062 2014-01-18T14:28:52.815 -0.001 -0.000 -0.003 35075 2014-01-19T13:38:52.815 0.000 -0.000 -0.002 35094 2014-01-21T02:15:52.815 -0.000 -0.000 -0.002 35114 2014-01-22T15:39:52.815 0.000 -0.000 0.001 35133 2014-01-24T03:11:52.815 0.000 0.000 0.002 35151 2014-01-25T12:50:52.815 -0.000 -0.000 -0.000 35169 2014-01-26T21:28:52.815 0.000 0.000 -0.000 35190 2014-01-28T13:45:52.815 0.000 0.000 0.000 35210 2014-01-30T03:11:52.815 -0.000 -0.000 -0.000 35227 2014-01-31T11:00:52.815 -0.000 -0.000 -0.002 35242 2014-02-01T15:08:52.815 0.000 0.000 0.001 35254 2014-02-02T12:23:52.815 -0.000 -0.000 0.000 35272 2014-02-03T23:11:52.815 -0.000 0.000 -0.001 35290 2014-02-05T08:51:52.815 -0.000 0.000 -0.001 35311 2014-02-06T23:54:52.815 0.001 -0.000 0.003 35331 2014-02-08T13:29:52.815 -0.000 -0.000 -0.001 35348 2014-02-09T20:10:52.814 0.000 -0.000 -0.000 35367 2014-02-11T08:53:52.814 0.000 0.000 0.000 35385 2014-02-12T18:30:52.814 -0.000 -0.000 -0.000 35403 2014-02-14T04:07:52.814 -0.000 0.000 -0.000 35421 2014-02-15T13:47:52.814 -0.000 -0.000 -0.000 35438 2014-02-16T20:29:52.814 -0.000 0.000 0.000 35458 2014-02-18T11:00:52.814 0.001 -0.000 0.002 35476 2014-02-19T20:36:52.814 -0.000 0.000 -0.001 35496 2014-02-21T10:01:52.814 -0.000 -0.000 -0.000 35517 2014-02-23T00:13:52.814 0.000 -0.000 -0.000 35538 2014-02-24T15:45:52.814 0.000 -0.000 -0.001 35556 2014-02-26T01:57:52.814 -0.000 0.000 -0.001 35574 2014-02-27T11:55:52.814 -0.000 0.000 -0.001 35592 2014-02-28T21:34:52.814 -0.000 -0.000 -0.001 35602 2014-03-01T15:13:52.814 0.000 0.000 -0.000 35623 2014-03-03T07:33:52.814 0.000 -0.000 0.000 35642 2014-03-04T19:06:52.814 0.000 -0.000 0.001 35661 2014-03-06T06:36:52.814 0.000 0.000 0.001 35680 2014-03-07T18:09:52.814 0.001 0.000 0.002 35694 2014-03-08T20:20:52.814 -0.000 -0.000 -0.001 35705 2014-03-09T15:51:52.814 0.000 0.001 0.001 35717 2014-03-10T15:18:52.814 0.000 -0.000 0.001 35733 2014-03-11T20:58:52.814 -0.002 0.000 -0.002 35748 2014-03-13T01:18:52.814 0.002 0.000 0.003 35766 2014-03-14T11:00:52.814 -0.001 -0.000 -0.002 35784 2014-03-15T20:38:52.814 0.000 0.000 0.001 35796 2014-03-16T18:00:52.814 -0.001 -0.000 0.002 35816 2014-03-18T08:31:52.814 0.000 -0.000 0.001 35832 2014-03-19T14:14:52.814 -0.001 -0.000 -0.001 35851 2014-03-21T01:57:52.814 0.000 0.000 0.000 35869 2014-03-22T11:39:07.814 0.002 -0.000 0.003 35886 2014-03-23T18:18:52.814 0.000 0.000 -0.000 35911 2014-03-25T18:09:52.814 0.001 -0.000 0.002 35936 2014-03-27T16:54:52.814 -0.001 0.000 -0.001 35959 2014-03-29T11:55:52.814 0.002 -0.000 0.002 35975 2014-03-30T16:43:52.814 -0.000 -0.000 0.000