Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue May 14 10:42:14 PDT 2019 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 58272 through 59426): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2019 JAN 01 00:01:10.000 2019 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_rec58347_58269_58347_r-v1.bsp spk_psp_rec58424_58344_58424_r-v1.bsp spk_psp_rec58520_58423_58520_r-v1.bsp spk_psp_rec58613_58517_58613_r-v1.bsp spk_psp_rec58706_58611_58706_r-v1.bsp spk_psp_rec58796_58704_58796_r-v1.bsp spk_psp_rec58887_58794_58887_r-v1.bsp spk_psp_rec58975_58885_58975_r-v1.bsp spk_psp_rec59065_58973_59065_r-v1.bsp spk_psp_rec59155_59064_59155_r-v1.bsp spk_psp_rec59245_59153_59245_r-v1.bsp spk_psp_rec59336_59243_59336_r-v1.bsp spk_psp_rec59426_59334_59426_r-v1.bsp spk_psp_rec59509_59424_59509_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_psp50.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 58283 2019-01-01T21:53:50.816 0.002 -0.000 0.001 58296 2019-01-02T22:13:50.816 -0.009 -0.000 -0.004 58309 2019-01-03T22:24:50.816 0.008 -0.000 0.004 58321 2019-01-04T20:59:50.815 -0.007 0.000 -0.003 58336 2019-01-05T23:57:50.815 0.001 -0.000 -0.000 58344 2019-01-06T16:33:50.815 -0.003 0.000 0.001 58360 2019-01-07T21:56:50.815 -0.000 -0.000 -0.000 58373 2019-01-08T22:15:50.815 -0.003 -0.000 -0.002 58393 2019-01-10T11:40:50.815 -0.004 -0.000 -0.002 58411 2019-01-11T21:20:50.815 0.009 -0.000 0.004 58423 2019-01-12T19:22:50.815 0.013 -0.000 0.005 58443 2019-01-14T09:11:50.815 0.014 0.000 0.007 58457 2019-01-15T11:22:50.815 -0.004 -0.000 -0.002 58476 2019-01-16T22:17:50.815 -0.006 -0.000 -0.000 58501 2019-01-18T21:40:50.815 0.002 0.000 0.001 58517 2019-01-20T04:10:50.815 0.001 0.000 -0.001 58539 2019-01-21T20:45:50.815 0.002 -0.000 0.001 58547 2019-01-22T11:27:50.815 0.009 -0.000 0.005 58566 2019-01-23T22:12:50.815 -0.006 0.000 0.003 58578 2019-01-24T21:42:50.815 0.008 -0.000 0.004 58592 2019-01-25T23:53:50.815 -0.000 0.000 -0.000 58611 2019-01-27T10:10:50.815 -0.004 -0.000 0.002 58630 2019-01-28T22:12:50.815 -0.005 0.000 0.001 58643 2019-01-29T22:12:50.815 0.003 -0.000 -0.002 58655 2019-01-30T21:44:50.815 -0.006 0.000 -0.003 58669 2019-01-31T23:55:50.815 0.002 -0.000 0.001 58681 2019-02-01T22:11:50.815 0.003 -0.000 0.002 58694 2019-02-02T22:06:50.815 -0.004 0.000 -0.000 58704 2019-02-03T16:49:50.815 -0.000 0.000 -0.000 58719 2019-02-04T21:26:50.815 0.001 -0.000 0.001 58732 2019-02-05T20:56:50.815 0.001 -0.000 -0.000 58745 2019-02-06T22:04:50.815 -0.001 -0.000 -0.000 58758 2019-02-07T21:56:50.815 -0.005 -0.000 -0.002 58771 2019-02-08T21:51:50.815 0.008 -0.000 -0.003 58784 2019-02-09T22:51:50.815 -0.005 0.000 -0.003 58794 2019-02-10T16:26:50.814 -0.004 -0.000 0.002 58816 2019-02-12T10:36:50.814 0.001 -0.000 0.001 58829 2019-02-13T10:35:50.814 -0.002 -0.000 -0.000 58841 2019-02-14T09:38:50.814 -0.001 -0.000 -0.000 58861 2019-02-15T23:02:50.814 0.009 0.000 0.004 58873 2019-02-16T21:29:50.814 -0.004 -0.000 -0.002 58885 2019-02-17T19:05:50.814 -0.002 -0.000 0.001 58900 2019-02-18T23:57:50.814 -0.001 -0.000 -0.001 58912 2019-02-19T22:00:50.814 -0.004 0.000 -0.002 58925 2019-02-20T21:46:50.814 -0.000 -0.000 0.000 58950 2019-02-22T21:30:50.814 0.002 0.000 0.001 58962 2019-02-23T19:57:50.814 -0.001 -0.000 -0.001 58973 2019-02-24T15:15:50.814 0.001 0.000 -0.001 58994 2019-02-26T07:48:50.814 0.004 0.000 0.002 59008 2019-02-27T09:59:50.814 -0.001 -0.000 -0.001 59021 2019-02-28T10:00:50.814 0.006 -0.000 0.003 59040 2019-03-01T21:51:50.814 -0.005 0.000 -0.003 59052 2019-03-02T20:17:50.814 0.001 0.000 0.001 59064 2019-03-03T17:28:50.814 0.006 -0.000 -0.003 59078 2019-03-04T20:55:50.814 0.003 0.000 0.001 59090 2019-03-05T18:49:50.814 0.001 0.000 0.000 59104 2019-03-06T21:33:50.814 0.002 -0.000 0.001 59117 2019-03-07T21:49:50.814 0.006 -0.000 0.004 59131 2019-03-08T23:57:50.814 -0.003 -0.000 -0.002 59144 2019-03-09T23:57:50.814 -0.009 0.000 -0.004 59153 2019-03-10T17:01:50.814 0.006 0.000 0.004 59168 2019-03-11T21:15:50.814 0.005 -0.000 0.003 59179 2019-03-12T17:29:50.814 -0.006 0.000 -0.003 59194 2019-03-13T21:39:50.814 0.002 0.000 0.001 59213 2019-03-15T09:25:50.814 0.003 -0.000 0.002 59231 2019-03-16T19:05:50.814 -0.001 -0.000 -0.000 59243 2019-03-17T16:16:50.814 0.002 -0.000 -0.001 59259 2019-03-18T23:28:50.814 0.002 0.000 0.001 59271 2019-03-19T21:43:50.814 0.001 0.000 0.001 59284 2019-03-20T21:38:50.814 0.002 0.000 0.000 59298 2019-03-21T23:57:50.814 -0.009 0.000 -0.003 59309 2019-03-22T20:58:50.814 0.004 -0.000 0.002 59324 2019-03-23T23:57:50.814 0.003 0.000 -0.002 59334 2019-03-24T18:28:50.814 0.000 0.000 -0.000 59349 2019-03-25T23:47:50.814 0.002 -0.000 0.001 59361 2019-03-26T21:38:50.814 -0.001 0.000 -0.000 59375 2019-03-27T23:57:50.814 0.004 0.000 0.001 59380 2019-03-28T09:03:50.814 -0.001 0.000 0.000 59400 2019-03-29T23:11:50.814 0.001 0.000 0.001 59413 2019-03-30T23:30:50.814 -0.003 -0.000 -0.002 59424 2019-03-31T18:48:50.814 0.004 -0.000 -0.002