Mars Reconnaissance Orbiter Primary Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Wed Apr 25 14:45:45 PDT 2007 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 Primary Science Phase of the MRO mission (orbits 2023 through 3177): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2007 JAN 01 00:01:05.183 2007 APR 01 01:01:05.185 Status -------------------------------------------------------- This file was created by merging regular reconstructed OD solution SPK files produced by the MRO NAV team during the Primary 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_rec02028_01970_02028_r-v1.bsp spk_psp_rec02117_02110_02381_r-v1.bsp spk_psp_rec02125_02028_02125_r-v1.bsp spk_psp_rec02192_02124_02192_r-v1.bsp spk_psp_rec02298_02192_02298_r-v1.bsp spk_psp_rec02375_02297_02375_r-v1.bsp spk_psp_rec02486_02374_02486_r-v1.bsp spk_psp_rec02571_02485_02571_r-v1.bsp spk_psp_rec02669_02570_02669_r-v1.bsp spk_psp_rec02740_02669_02740_r-v1.bsp spk_psp_rec02844_02739_02844_r-v1.bsp spk_psp_rec02919_02844_02919_r-v1.bsp spk_psp_rec03029_02919_03029_r-v1.bsp spk_psp_rec03106_03029_03106_r-v1.bsp spk_psp_rec03209_03105_03209_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_psp2.bsp: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 2028 2007-01-01T10:43:54.816 0.003 0.000 -0.002 2046 2007-01-02T20:26:54.816 0.002 0.000 -0.002 2071 2007-01-04T18:58:54.815 0.002 -0.000 -0.001 2088 2007-01-06T02:43:54.815 -0.002 0.000 0.000 2102 2007-01-07T04:58:54.815 0.002 0.000 -0.000 2124 2007-01-08T22:18:54.815 0.001 -0.000 -0.001 2138 2007-01-10T00:28:54.815 0.001 -0.000 -0.001 2148 2007-01-10T19:13:54.815 -0.001 0.000 0.001 2170 2007-01-12T12:18:54.815 0.001 0.000 -0.001 2192 2007-01-14T05:28:54.815 0.000 0.000 -0.000 2213 2007-01-15T20:43:54.815 0.000 -0.000 -0.000 2228 2007-01-17T01:43:54.815 0.000 -0.000 -0.000 2241 2007-01-18T00:58:54.815 0.001 0.000 -0.001 2262 2007-01-19T16:18:54.815 -0.001 0.000 0.002 2285 2007-01-21T11:08:54.815 0.002 -0.000 -0.001 2297 2007-01-22T09:58:54.815 0.001 0.000 -0.001 2320 2007-01-24T05:18:54.815 -0.000 -0.000 0.000 2340 2007-01-25T18:21:54.815 0.001 0.000 -0.001 2355 2007-01-26T22:12:54.815 -0.001 -0.000 0.001 2374 2007-01-28T09:45:54.815 -0.000 0.000 0.000 2396 2007-01-30T02:48:54.815 -0.002 -0.000 0.002 2408 2007-01-31T02:43:54.815 0.001 0.000 0.001 2426 2007-02-01T10:58:54.815 -0.001 -0.000 0.001 2447 2007-02-03T02:13:54.815 0.002 0.000 -0.003 2469 2007-02-04T19:23:54.815 0.000 0.000 -0.000 2485 2007-02-06T01:18:54.815 0.001 0.001 -0.001 2502 2007-02-07T08:58:54.815 0.001 -0.000 -0.001 2511 2007-02-08T02:58:54.815 -0.001 0.000 -0.002 2532 2007-02-09T16:58:54.815 0.000 0.000 -0.000 2549 2007-02-11T00:58:54.814 -0.001 -0.000 0.001 2570 2007-02-12T16:08:54.814 -0.000 -0.000 0.000 2587 2007-02-13T23:58:54.814 0.001 0.000 -0.001 2608 2007-02-15T15:58:54.814 -0.000 0.000 -0.000 2627 2007-02-17T02:53:54.814 0.002 0.000 -0.002 2648 2007-02-18T18:13:54.814 -0.001 0.000 0.002 2669 2007-02-20T09:28:54.814 0.001 -0.000 -0.001 2690 2007-02-22T00:43:54.814 -0.001 0.000 0.002 2711 2007-02-23T15:56:54.814 0.001 0.000 -0.001 2726 2007-02-24T19:58:54.814 -0.000 0.000 0.000 2739 2007-02-25T20:28:54.814 0.002 0.000 -0.003 2759 2007-02-27T09:43:54.814 0.001 0.000 -0.001 2774 2007-02-28T13:43:54.814 0.001 -0.000 -0.001 2797 2007-03-02T08:48:54.814 0.000 0.000 -0.000 2822 2007-03-04T07:42:54.814 0.001 0.000 -0.002 2844 2007-03-06T00:58:54.814 0.002 0.000 -0.003 2866 2007-03-07T17:43:54.814 0.001 -0.000 -0.001 2878 2007-03-08T16:13:54.814 0.000 -0.000 -0.001 2894 2007-03-09T22:13:54.814 -0.000 -0.000 0.001 2919 2007-03-11T20:58:54.814 0.001 0.000 -0.001 2939 2007-03-13T10:23:54.814 -0.001 -0.000 0.001 2955 2007-03-14T16:13:54.814 0.002 -0.000 -0.003 2976 2007-03-16T07:33:54.814 0.000 0.000 -0.000 2995 2007-03-17T18:58:54.814 0.001 0.000 -0.001 3014 2007-03-19T06:38:54.814 0.000 0.000 -0.000 3029 2007-03-20T10:55:54.814 0.000 -0.000 -0.001 3046 2007-03-21T18:27:54.814 0.000 0.000 -0.000 3068 2007-03-23T11:53:54.814 0.000 -0.000 -0.000 3085 2007-03-24T19:23:54.814 -0.000 -0.000 0.001 3105 2007-03-26T08:53:54.814 0.000 -0.000 -0.000 3125 2007-03-27T22:10:54.814 -0.000 0.000 0.000 3148 2007-03-29T16:58:54.814 -0.029 0.000 -0.000 3168 2007-03-31T06:28:54.814 -0.000 0.000 0.000