MAVEN Reconstructed SPK, NAV Solution, 2020-01-01 to 2020-04-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Wed May 6 08:56:28 PDT 2020 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 10634 through 11237): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2020 JAN 01 00:01:09.183 2020 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_10605-10658_rec_v1.bsp trj_orb_10657-10706_rec_v1.bsp trj_orb_10705-10770_rec_v1.bsp trj_orb_10770-10798_rec_v1.bsp trj_orb_10797-10857_rec_v1.bsp trj_orb_10856-10897_rec_v1.bsp trj_orb_10896-10956_rec_v1.bsp trj_orb_10949-10996_rec_v1.bsp trj_orb_10995-11037_rec_v1.bsp trj_orb_11036-11097_rec_v1.bsp trj_orb_11096-11142_rec_v1.bsp trj_orb_11141-11190_rec_v1.bsp trj_orb_11189-11229_rec_v1.bsp trj_orb_11228-11282_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_200101_200401_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 10639 2020-01-01T19:52:17.816 0.004 -0.001 0.002 10652 2020-01-03T18:29:50.816 0.007 -0.001 0.002 10657 2020-01-04T13:10:54.815 -0.001 0.001 -0.001 10666 2020-01-05T21:34:22.815 0.011 -0.004 0.006 10670 2020-01-06T13:13:50.815 -0.011 0.001 -0.000 10677 2020-01-07T13:28:50.815 -0.002 0.001 -0.002 10681 2020-01-08T05:58:50.815 -0.004 -0.001 0.002 10691 2020-01-09T17:38:50.815 0.007 0.001 -0.001 10697 2020-01-10T13:43:50.815 -0.004 0.002 -0.003 10705 2020-01-11T19:03:50.815 -0.017 0.006 -0.012 10718 2020-01-13T17:43:50.815 -0.001 0.000 -0.001 10730 2020-01-15T13:28:50.815 0.003 -0.001 0.003 10744 2020-01-17T17:05:04.048 -0.002 0.000 -0.001 10751 2020-01-18T17:18:41.918 -0.000 0.000 0.000 10758 2020-01-19T18:39:14.815 0.004 -0.001 0.005 10764 2020-01-20T16:59:50.577 -0.003 0.001 -0.004 10770 2020-01-21T14:08:50.815 -0.003 0.001 -0.005 10779 2020-01-22T23:03:50.815 -0.000 0.000 -0.000 10790 2020-01-24T15:07:09.815 -0.019 0.006 -0.026 10797 2020-01-25T18:16:48.815 -0.013 -0.005 0.019 10806 2020-01-27T00:35:24.815 -0.004 0.002 -0.009 10817 2020-01-28T17:09:45.815 -0.003 0.001 -0.005 10824 2020-01-29T17:28:50.815 0.002 -0.001 0.004 10837 2020-01-31T16:58:50.815 -0.003 0.001 -0.008 10847 2020-02-02T07:13:50.815 0.008 0.003 -0.014 10856 2020-02-03T13:28:50.815 -0.004 0.002 -0.014 10863 2020-02-04T14:43:50.815 0.001 -0.001 0.005 10869 2020-02-05T15:01:41.417 0.000 -0.000 -0.001 10876 2020-02-06T13:46:08.815 0.000 -0.000 0.002 10884 2020-02-07T18:40:50.815 -0.003 0.001 -0.010 10890 2020-02-08T16:57:50.815 0.006 -0.002 0.043 10896 2020-02-09T14:46:50.815 0.003 -0.001 0.021 10911 2020-02-11T20:35:51.814 0.002 -0.001 0.033 10929 2020-02-14T13:36:32.814 0.000 -0.000 -0.012 10940 2020-02-16T06:13:50.814 0.004 -0.001 -0.071 10942 2020-02-16T13:43:50.814 -0.006 0.001 0.084 10949 2020-02-17T14:04:50.814 -0.003 0.001 0.023 10960 2020-02-19T06:46:50.814 -0.000 0.000 0.001 10967 2020-02-20T07:11:50.814 0.001 -0.000 -0.004 10976 2020-02-21T16:43:50.814 -0.001 0.000 0.002 10986 2020-02-23T05:23:50.814 0.003 0.000 -0.008 10995 2020-02-24T13:58:50.814 0.008 0.001 -0.020 11000 2020-02-25T06:27:39.612 0.003 -0.001 -0.007 11009 2020-02-26T15:01:50.814 -0.015 0.006 0.029 11015 2020-02-27T12:32:50.814 0.011 -0.004 -0.008 11022 2020-02-28T13:43:12.814 0.003 -0.001 0.001 11029 2020-02-29T16:33:16.814 -0.014 0.000 0.029 11036 2020-03-01T16:12:30.814 0.003 -0.001 0.003 11043 2020-03-02T17:58:50.814 -0.008 0.003 0.012 11053 2020-03-04T06:58:50.814 0.022 -0.003 -0.040 11068 2020-03-06T12:21:50.814 0.000 -0.000 -0.000 11076 2020-03-07T16:58:50.814 -0.003 0.001 0.001 11084 2020-03-08T21:58:50.814 0.001 -0.000 -0.001 11096 2020-03-10T17:13:50.814 0.009 -0.003 -0.003 11104 2020-03-11T22:28:50.814 0.002 -0.001 -0.002 11115 2020-03-13T13:55:50.814 -0.014 0.006 0.007 11123 2020-03-14T18:19:50.814 0.018 -0.002 0.015 11130 2020-03-15T20:11:50.814 -0.006 0.002 0.003 11141 2020-03-17T12:31:37.814 -0.002 0.000 0.002 11156 2020-03-19T17:25:10.814 0.025 -0.002 0.017 11161 2020-03-20T12:50:53.814 -0.012 0.002 0.009 11169 2020-03-21T17:13:50.814 0.027 -0.010 -0.015 11177 2020-03-22T22:13:50.814 -0.048 0.015 0.027 11189 2020-03-24T16:42:50.814 0.006 -0.002 0.001 11197 2020-03-25T21:48:50.814 -0.006 0.003 0.001 11209 2020-03-27T18:18:50.814 0.003 -0.000 -0.001 11219 2020-03-29T05:08:50.814 0.011 -0.004 -0.000 11228 2020-03-30T13:32:50.814 0.026 -0.010 0.000 11234 2020-03-31T11:58:50.814 -0.008 0.002 0.002 End of comments.