MAVEN Reconstructed SPK, NAV Solution, 2022-01-01 to 2022-04-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue Apr 19 07:56:52 PDT 2022 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 15499 through 16097): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2022 JAN 01 00:01:09.183 2022 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_15470-15524_rec_v1.bsp trj_orb_15523-15564_rec_v1.bsp trj_orb_15563-15604_rec_v1.bsp trj_orb_15603-15657_rec_v1.bsp trj_orb_15656-15697_rec_v1.bsp trj_orb_15696-15750_rec_v1.bsp trj_orb_15749-15798_rec_v1.bsp trj_orb_15797-15841_rec_v1.bsp trj_orb_15840-15890_rec_v1.bsp trj_orb_15889-15937_rec_v1.bsp trj_orb_15936-15983_rec_v1.bsp trj_orb_15982-16030_rec_v1.bsp trj_orb_16029-16060_rec_v1.bsp trj_orb_16059-16127_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_220101_220401_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 15510 2022-01-02T18:36:50.816 0.014 -0.006 -0.005 15523 2022-01-04T16:58:50.815 0.008 -0.002 0.004 15529 2022-01-05T14:33:50.815 0.002 -0.001 0.001 15547 2022-01-08T08:28:50.815 -0.016 0.005 0.007 15557 2022-01-09T20:28:50.815 0.018 -0.005 -0.005 15563 2022-01-10T18:33:50.815 -0.019 0.002 0.009 15570 2022-01-11T19:28:50.815 -0.013 0.003 0.003 15582 2022-01-13T14:38:50.815 0.040 -0.011 -0.006 15589 2022-01-14T15:33:50.815 0.024 -0.009 0.002 15598 2022-01-15T23:43:50.815 -0.027 0.011 -0.009 15603 2022-01-16T19:23:50.815 -0.027 -0.005 0.010 15618 2022-01-19T00:28:50.815 0.002 -0.000 0.000 15630 2022-01-20T19:43:50.815 0.002 -0.001 0.000 15643 2022-01-22T18:23:50.815 -0.003 0.001 -0.001 15651 2022-01-23T22:38:50.815 0.009 -0.003 0.003 15656 2022-01-24T18:21:50.815 -0.026 -0.003 0.001 15670 2022-01-26T19:09:50.815 0.005 -0.002 0.002 15676 2022-01-27T17:08:50.815 0.007 -0.003 0.003 15686 2022-01-29T07:03:50.815 -0.010 -0.004 0.001 15696 2022-01-30T18:18:50.815 -0.001 -0.000 -0.000 15706 2022-02-01T07:00:50.815 -0.002 -0.000 -0.000 15715 2022-02-02T14:10:50.815 0.007 -0.002 0.003 15726 2022-02-04T06:55:50.815 -0.019 -0.004 -0.006 15733 2022-02-05T07:28:50.815 -0.051 0.007 -0.023 15749 2022-02-07T18:08:50.815 -0.032 -0.010 -0.011 15757 2022-02-08T20:43:50.815 -0.001 0.000 0.000 15776 2022-02-11T18:08:50.814 0.011 -0.003 0.006 15783 2022-02-12T18:42:50.814 -0.041 0.015 0.001 15797 2022-02-14T22:13:50.814 -0.054 0.008 -0.036 15806 2022-02-16T06:48:50.814 0.036 -0.003 0.026 15815 2022-02-17T14:13:50.814 -0.040 0.016 -0.001 15824 2022-02-18T23:16:50.814 0.009 -0.003 0.006 15833 2022-02-20T07:24:50.814 0.040 -0.015 0.014 15840 2022-02-21T08:58:50.814 0.031 -0.008 0.020 15850 2022-02-22T21:28:50.814 0.001 -0.000 0.001 15862 2022-02-24T16:28:50.814 0.008 -0.001 0.006 15876 2022-02-26T17:58:50.814 0.003 -0.001 -0.003 15889 2022-02-28T17:53:50.814 -0.008 0.001 -0.006 15903 2022-03-02T20:18:50.814 0.003 -0.000 0.002 15913 2022-03-04T07:18:50.814 -0.001 0.000 0.001 15922 2022-03-05T17:53:50.814 0.002 0.000 0.003 15936 2022-03-07T18:23:50.814 0.001 -0.000 -0.002 15946 2022-03-09T06:13:50.814 -0.001 0.000 0.002 15961 2022-03-11T13:18:50.814 -0.001 0.000 -0.001 15966 2022-03-12T07:28:50.814 0.002 -0.000 0.003 15973 2022-03-13T08:28:50.814 -0.003 0.000 -0.001 15982 2022-03-14T15:53:50.814 -0.001 0.000 0.005 15990 2022-03-15T21:33:50.814 0.002 -0.001 -0.002 15999 2022-03-17T05:57:50.814 -0.001 0.000 0.001 16004 2022-03-17T23:55:50.814 -0.000 0.000 0.001 16013 2022-03-19T07:41:50.814 -0.000 0.000 0.000 16019 2022-03-20T06:02:50.814 0.001 -0.000 -0.003 16029 2022-03-21T17:48:50.814 0.000 -0.000 -0.006 16041 2022-03-23T13:13:50.814 0.000 -0.000 -0.026 16049 2022-03-24T18:58:50.814 0.002 -0.000 -0.018 16059 2022-03-26T05:42:50.814 0.001 -0.000 0.016 16069 2022-03-27T17:46:50.814 -0.001 0.000 -0.006 16079 2022-03-29T06:58:50.814 0.001 -0.000 -0.000 16088 2022-03-30T15:28:50.814 -0.001 0.000 0.000 End of comments.