MAVEN Reconstructed SPK, NAV Solution, 2020-07-01 to 2020-10-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Fri Oct 30 15:30:02 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 11845 through 12457): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2020 JUL 01 00:01:09.184 2020 OCT 01 01:01:09.182 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_11842-11890_rec_v1.bsp trj_orb_11889-11929_rec_v1.bsp trj_orb_11889-11929_rec_v2.bsp trj_orb_11928-11976_rec_v1.bsp trj_orb_11975-12029_rec_v1.bsp trj_orb_12028-12076_rec_v1.bsp trj_orb_12075-12121_rec_v1.bsp trj_orb_12120-12170_rec_v1.bsp trj_orb_12152-12216_rec_v1.bsp trj_orb_12215-12256_rec_v1.bsp trj_orb_12255-12301_rec_v1.bsp trj_orb_12300-12346_rec_v1.bsp trj_orb_12345-12402_rec_v1.bsp trj_orb_12401-12449_rec_v1.bsp trj_orb_12448-12495_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_200701_201001_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 11852 2020-07-02T05:38:50.815 0.010 -0.003 0.022 11862 2020-07-03T17:13:50.815 0.015 -0.006 0.023 11873 2020-07-05T08:43:50.816 -0.003 0.001 -0.004 11881 2020-07-06T13:27:50.816 -0.015 0.005 -0.013 11889 2020-07-07T18:34:30.816 -0.023 0.009 -0.033 11898 2020-07-09T02:35:28.816 -0.010 0.004 -0.006 11902 2020-07-09T16:58:07.816 0.012 -0.004 0.006 11912 2020-07-11T05:13:50.816 0.018 -0.007 0.019 11922 2020-07-12T17:53:50.816 -0.035 0.006 -0.046 11928 2020-07-13T16:03:50.816 -0.011 -0.001 -0.013 11936 2020-07-14T19:18:50.816 -0.001 0.001 -0.001 11947 2020-07-16T10:58:50.816 -0.010 0.004 -0.004 11954 2020-07-17T11:38:50.816 0.004 -0.001 -0.004 11961 2020-07-18T13:11:50.816 0.007 -0.003 0.000 11967 2020-07-19T10:46:50.816 0.002 -0.001 0.000 11971 2020-07-20T01:07:20.816 -0.028 0.010 0.003 11975 2020-07-20T15:30:27.816 -0.028 0.010 0.004 11985 2020-07-22T03:32:45.816 -0.006 0.002 0.000 11992 2020-07-23T04:32:43.816 0.007 -0.002 -0.003 12005 2020-07-25T03:58:50.816 0.005 -0.002 0.003 12016 2020-07-26T19:58:50.816 0.035 -0.005 0.023 12028 2020-07-28T14:18:50.816 -0.028 0.011 0.003 12039 2020-07-30T05:38:50.816 0.015 -0.005 -0.007 12054 2020-08-01T11:37:50.816 -0.003 0.001 0.001 12064 2020-08-03T00:27:50.816 0.002 -0.000 0.001 12075 2020-08-04T14:49:36.816 -0.004 0.001 0.003 12084 2020-08-06T00:28:57.816 -0.003 0.001 -0.001 12095 2020-08-07T15:18:50.816 0.007 -0.003 -0.003 12105 2020-08-09T03:58:50.816 -0.011 0.002 -0.001 12111 2020-08-10T00:43:50.816 0.018 -0.007 -0.011 12120 2020-08-11T10:38:50.816 0.030 0.006 0.013 12127 2020-08-12T11:13:50.817 0.006 -0.001 0.000 12134 2020-08-13T12:13:50.817 -0.007 0.001 0.001 12141 2020-08-14T13:58:50.817 0.008 0.001 0.002 12147 2020-08-15T10:50:04.817 -0.004 0.001 0.001 12152 2020-08-16T04:00:25.817 0.003 -0.001 -0.002 12169 2020-08-18T16:58:50.817 -0.007 0.002 0.004 12178 2020-08-20T03:55:50.817 -0.004 -0.002 -0.003 12188 2020-08-21T14:43:50.817 0.022 -0.001 -0.005 12192 2020-08-22T03:40:50.817 -0.019 0.005 0.011 12198 2020-08-23T02:11:50.817 0.008 -0.002 -0.005 12205 2020-08-24T02:51:50.817 -0.002 0.001 0.002 12215 2020-08-25T14:43:50.817 -0.002 0.001 0.001 12221 2020-08-26T14:18:50.817 -0.003 -0.001 -0.001 12227 2020-08-27T09:43:50.817 0.022 -0.008 -0.017 12233 2020-08-28T09:42:19.817 -0.010 -0.004 -0.005 12239 2020-08-29T05:47:21.817 -0.064 0.013 0.045 12250 2020-08-30T22:42:14.817 0.003 0.001 0.001 12255 2020-08-31T14:37:16.817 -0.041 0.016 0.038 12264 2020-09-01T23:42:03.817 0.015 -0.003 -0.012 12272 2020-09-03T03:48:00.817 -0.016 0.006 0.015 12282 2020-09-04T15:58:50.817 0.009 -0.003 -0.009 12292 2020-09-06T04:18:50.817 0.001 -0.000 -0.001 12300 2020-09-07T10:16:50.817 0.018 0.006 -0.005 12308 2020-09-08T13:05:50.817 -0.011 0.004 0.008 12319 2020-09-10T04:38:50.817 0.006 -0.002 -0.005 12328 2020-09-11T13:13:50.817 -0.005 0.002 0.005 12332 2020-09-12T03:28:50.817 -0.006 0.002 0.005 12340 2020-09-13T09:33:50.817 0.005 0.000 -0.005 12345 2020-09-14T02:18:50.817 -0.004 0.001 0.004 12354 2020-09-15T10:30:11.817 0.012 -0.005 -0.008 12358 2020-09-16T00:54:48.817 -0.014 0.005 0.010 12364 2020-09-16T22:33:12.817 -0.010 0.004 0.008 12368 2020-09-17T12:56:50.817 0.008 -0.003 -0.006 12375 2020-09-18T14:48:50.817 0.006 -0.001 -0.008 12378 2020-09-19T01:03:50.817 -0.003 0.001 0.002 12391 2020-09-21T00:28:50.817 -0.010 0.003 0.014 12401 2020-09-22T13:33:50.817 -0.012 -0.003 0.015 12413 2020-09-24T08:23:50.817 -0.000 0.000 0.001 12421 2020-09-25T13:43:50.817 -0.002 -0.000 0.003 12426 2020-09-26T06:13:50.817 0.001 -0.000 -0.001 12431 2020-09-27T01:48:50.817 0.016 0.004 -0.023 12439 2020-09-28T05:33:50.817 -0.001 0.000 0.001 12448 2020-09-29T13:39:50.817 -0.003 0.001 0.003 End of comments.