MAVEN Reconstructed SPK, NAV Solution, 2023-01-01 to 2023-04-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Wed May 3 07:00:27 PDT 2023 Objects in the Ephemeris -------------------------------------------------------- This SPK file contains ephemeris data for the Mars Atmosphere and Volatile Evolution Mission (MAVEN) spacecraft. The NAIF ID code for MAVEN is -202. Approximate Time Coverage -------------------------------------------------------- This file covers the following part of the orbital phase of the MAVEN mission (orbits 17914 through 18505): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2023 JAN 01 00:01:09.183 2023 APR 01 01:01:09.185 Status -------------------------------------------------------- This file was created by merging regular reconstructed OD solution SPK files produced by the MAVEN NAV team during the orbital 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 MAVEN project data base by the MAVEN 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 DE430 planetary ephemeris and MAR097 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: trj_orb_17874-17952_rec_v1.bsp trj_orb_17951-18015_rec_v1.bsp trj_orb_18014-18064_rec_v1.bsp trj_orb_18063-18109_rec_v1.bsp trj_orb_18108-18158_rec_v1.bsp trj_orb_18157-18203_rec_v1.bsp trj_orb_18202-18242_rec_v1.bsp trj_orb_18241-18301_rec_v1.bsp trj_orb_18300-18347_rec_v1.bsp trj_orb_18346-18380_rec_v1.bsp trj_orb_18379-18434_rec_v1.bsp trj_orb_18433-18481_rec_v1.bsp trj_orb_18480-18512_rec_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 ./maven_orb_rec_230101_230401_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 17920 2023-01-01T22:28:50.816 -0.000 0.000 -0.001 17929 2023-01-03T08:38:50.816 0.002 0.000 -0.011 17944 2023-01-05T15:58:50.815 -0.000 -0.000 0.003 17951 2023-01-06T16:28:50.815 -0.000 0.000 0.000 17961 2023-01-08T04:28:50.815 0.000 -0.000 0.002 17971 2023-01-09T16:43:50.815 0.000 -0.000 0.002 17978 2023-01-10T18:38:50.815 -0.001 0.000 -0.003 17984 2023-01-11T16:28:50.815 0.001 -0.000 0.003 18002 2023-01-14T10:58:50.815 -0.001 0.000 0.002 18014 2023-01-16T05:48:50.815 -0.000 0.000 -0.002 18024 2023-01-17T18:33:50.815 -0.000 0.000 -0.001 18031 2023-01-18T20:13:50.815 -0.000 0.000 -0.001 18036 2023-01-19T14:48:50.815 -0.001 0.000 -0.000 18044 2023-01-20T21:18:50.815 0.001 0.000 -0.003 18051 2023-01-21T21:08:50.815 -0.000 0.000 -0.001 18063 2023-01-23T18:04:50.815 -0.000 0.000 0.000 18083 2023-01-26T18:28:50.815 0.001 -0.000 0.001 18090 2023-01-27T20:23:50.815 0.000 -0.000 0.000 18099 2023-01-29T04:28:50.815 0.001 -0.000 0.001 18108 2023-01-30T13:58:50.815 -0.003 0.001 -0.001 18116 2023-01-31T19:28:50.815 -0.001 0.000 -0.000 18125 2023-02-02T03:26:50.815 0.002 -0.001 0.003 18136 2023-02-03T19:23:50.815 0.000 -0.000 0.000 18144 2023-02-05T00:38:50.815 -0.001 0.000 -0.001 18157 2023-02-07T01:58:50.815 -0.001 -0.000 0.001 18169 2023-02-08T20:28:50.815 0.002 -0.001 0.003 18179 2023-02-10T08:58:50.814 0.000 -0.000 0.001 18195 2023-02-12T19:28:50.814 -0.001 0.000 -0.001 18202 2023-02-13T20:43:50.814 0.002 -0.001 0.002 18213 2023-02-15T13:48:50.814 0.004 -0.001 0.002 18219 2023-02-16T10:43:50.814 -0.003 0.001 -0.003 18230 2023-02-18T03:45:50.814 0.002 -0.000 0.001 18241 2023-02-19T19:23:50.814 -0.005 0.002 -0.005 18254 2023-02-21T18:33:50.814 0.000 -0.000 0.000 18267 2023-02-23T18:13:50.814 -0.004 0.001 -0.003 18287 2023-02-26T19:12:50.814 0.002 -0.001 0.001 18300 2023-02-28T19:38:50.814 -0.003 0.001 -0.002 18313 2023-03-02T19:38:50.814 0.002 0.000 0.001 18326 2023-03-04T18:43:50.814 0.025 -0.003 0.011 18338 2023-03-06T14:58:50.814 -0.016 -0.001 -0.005 18346 2023-03-07T18:38:50.814 -0.003 0.001 -0.001 18353 2023-03-08T20:06:50.814 0.022 -0.007 0.003 18359 2023-03-09T19:22:50.814 -0.003 0.000 -0.001 18371 2023-03-11T14:13:50.814 -0.001 0.000 -0.000 18379 2023-03-12T19:13:50.814 -0.033 0.012 -0.005 18398 2023-03-15T16:20:50.814 0.012 -0.003 -0.002 18420 2023-03-19T02:18:50.814 -0.020 0.000 -0.006 18433 2023-03-21T00:43:50.814 0.002 -0.001 0.000 18450 2023-03-23T15:28:50.814 -0.001 0.001 -0.000 18460 2023-03-25T05:08:50.814 0.013 0.004 0.004 18471 2023-03-26T19:08:50.814 -0.001 0.000 0.000 18480 2023-03-28T05:28:50.814 0.006 -0.000 0.001 18487 2023-03-29T05:48:50.814 0.003 -0.001 -0.001 18497 2023-03-30T18:03:50.814 -0.010 0.003 0.004 End of comments.