Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu May 3 11:44:35 PDT 2018 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 53588 through 54742): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2018 JAN 01 00:01:10.000 2018 APR 01 01:01:09.185 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_rec53676_53584_53676_r-v1.bsp spk_psp_rec53765_53674_53765_r-v1.bsp spk_psp_rec53856_53763_53856_r-v1.bsp spk_psp_rec53941_53854_53941_r-v1.bsp spk_psp_rec54032_53940_54032_r-v1.bsp spk_psp_rec54124_54030_54124_r-v1.bsp spk_psp_rec54172_54122_54172_r-v1.bsp spk_psp_rec54304_54170_54304_r-v1.bsp spk_psp_rec54394_54302_54394_r-v1.bsp spk_psp_rec54477_54392_54477_r-v1.bsp spk_psp_rec54566_54475_54566_r-v1.bsp spk_psp_rec54662_54564_54662_r-v1.bsp spk_psp_rec54753_54660_54753_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_psp46.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 53598 2018-01-01T22:00:50.816 -0.000 -0.000 -0.001 53611 2018-01-02T22:19:50.816 -0.000 0.000 0.000 53625 2018-01-03T23:57:50.815 0.000 0.000 0.000 53643 2018-01-05T10:01:50.815 -0.000 0.000 -0.001 53660 2018-01-06T17:57:50.815 0.001 0.000 0.002 53674 2018-01-07T19:04:50.815 0.000 0.000 -0.000 53689 2018-01-08T23:44:50.815 -0.000 -0.000 -0.000 53714 2018-01-10T22:54:50.815 0.001 -0.000 0.002 53726 2018-01-11T21:22:50.815 -0.001 -0.000 -0.002 53740 2018-01-12T23:33:50.815 0.000 0.000 0.000 53752 2018-01-13T22:00:50.815 0.001 -0.000 0.002 53763 2018-01-14T17:40:50.815 -0.000 0.000 0.001 53785 2018-01-16T11:34:50.815 -0.000 -0.000 -0.001 53803 2018-01-17T21:22:50.815 0.001 0.000 0.003 53822 2018-01-19T08:54:50.815 -0.000 0.000 -0.001 53836 2018-01-20T11:08:50.815 0.000 0.000 0.000 53854 2018-01-21T19:40:50.815 0.000 0.000 -0.000 53865 2018-01-22T17:19:50.815 -0.000 -0.000 -0.000 53877 2018-01-23T15:14:50.815 -0.001 0.000 -0.000 53892 2018-01-24T19:35:50.815 -0.000 0.000 -0.001 53903 2018-01-25T16:22:50.815 0.001 0.000 0.002 53919 2018-01-26T22:18:50.815 0.000 -0.000 0.000 53932 2018-01-27T22:36:50.815 -0.000 0.000 -0.001 53940 2018-01-28T12:29:50.815 0.000 -0.000 -0.001 53958 2018-01-29T23:13:50.815 0.001 0.000 0.002 53971 2018-01-30T23:32:50.815 -0.000 0.000 -0.001 53983 2018-01-31T21:58:50.815 -0.000 -0.000 -0.001 53996 2018-02-01T22:17:50.815 0.000 -0.000 0.001 54009 2018-02-02T22:36:50.815 0.000 0.000 0.001 54030 2018-02-04T12:48:50.815 0.000 0.000 -0.000 54048 2018-02-05T23:30:50.815 0.000 0.000 0.000 54070 2018-02-07T16:40:50.815 -0.000 0.000 -0.001 54087 2018-02-09T00:38:50.815 -0.000 0.000 -0.001 54098 2018-02-09T21:01:50.814 0.000 -0.000 0.002 54109 2018-02-10T17:36:50.814 0.000 -0.000 0.000 54122 2018-02-11T16:50:50.814 -0.000 -0.000 0.000 54134 2018-02-12T16:21:50.814 -0.000 -0.000 -0.001 54147 2018-02-13T15:56:50.814 0.000 -0.000 -0.000 54163 2018-02-14T22:34:50.814 -0.000 0.000 -0.002 54170 2018-02-15T11:13:50.814 0.000 -0.000 0.000 54193 2018-02-17T06:43:50.814 -0.000 0.000 -0.000 54214 2018-02-18T22:00:40.814 0.000 -0.000 0.001 54234 2018-02-20T11:21:50.814 0.000 -0.000 0.001 54250 2018-02-21T16:43:50.814 0.000 0.000 -0.000 54266 2018-02-22T22:17:50.814 -0.000 0.000 0.000 54279 2018-02-23T23:30:50.814 0.000 -0.000 0.000 54291 2018-02-24T21:52:50.814 -0.000 0.000 -0.001 54302 2018-02-25T17:28:50.814 0.000 0.000 -0.000 54322 2018-02-27T07:54:50.814 0.000 0.000 0.001 54335 2018-02-28T07:36:50.814 0.000 -0.000 -0.000 54348 2018-03-01T08:31:50.814 -0.000 0.000 -0.001 54369 2018-03-02T23:48:50.814 -0.000 -0.000 -0.002 54381 2018-03-03T22:14:50.814 -0.000 -0.000 -0.000 54392 2018-03-04T17:45:50.814 0.000 0.000 -0.001 54413 2018-03-06T10:00:50.814 -0.000 0.000 0.000 54430 2018-03-07T17:52:50.814 0.001 0.000 0.002 54439 2018-03-08T10:03:50.814 -0.001 0.000 0.001 54457 2018-03-09T20:21:50.814 0.001 -0.000 0.002 54475 2018-03-11T04:57:50.814 -0.000 0.000 0.000 54493 2018-03-12T15:40:50.814 0.000 -0.000 0.000 54505 2018-03-13T14:07:50.814 -0.000 0.000 -0.001 54519 2018-03-14T16:17:50.814 0.000 0.000 0.001 54532 2018-03-15T16:36:50.814 -0.000 -0.000 -0.001 54549 2018-03-16T23:57:50.814 0.000 -0.000 0.001 54564 2018-03-18T03:26:50.814 -0.001 0.000 0.003 54583 2018-03-19T15:58:50.814 0.000 -0.000 0.001 54599 2018-03-20T21:53:50.814 -0.000 0.000 -0.001 54611 2018-03-21T20:19:50.814 0.001 -0.000 0.002 54626 2018-03-22T23:57:50.814 -0.000 -0.000 -0.000 54638 2018-03-23T22:49:50.814 0.000 -0.000 0.000 54651 2018-03-24T23:07:50.814 0.000 0.000 0.001 54660 2018-03-25T14:53:50.814 0.000 -0.000 -0.001 54673 2018-03-26T16:16:50.814 0.000 0.000 0.002 54686 2018-03-27T16:34:50.814 -0.000 0.000 -0.001 54701 2018-03-28T20:23:50.814 -0.000 -0.000 -0.000 54717 2018-03-30T02:09:50.814 -0.000 -0.000 -0.001 54737 2018-03-31T15:35:50.814 0.000 -0.000 0.001