MAVEN Reconstructed SPK, NAV Solution, 2022-10-01 to 2023-01-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu Feb 2 14:14:03 PST 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 17311 through 17913): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2022 OCT 01 00:01:09.182 2023 JAN 01 01:01:09.183 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_17289-17334_rec_v1.bsp trj_orb_17333-17376_rec_v1.bsp trj_orb_17375-17417_rec_v1.bsp trj_orb_17412-17466_rec_v1.bsp trj_orb_17465-17511_rec_v1.bsp trj_orb_17510-17558_rec_v1.bsp trj_orb_17557-17633_rec_v1.bsp trj_orb_17632-17657_rec_v1.bsp trj_orb_17656-17695_rec_v1.bsp trj_orb_17694-17736_rec_v1.bsp trj_orb_17735-17780_rec_v1.bsp trj_orb_17779-17823_rec_v1.bsp trj_orb_17822-17855_rec_v1.bsp trj_orb_17854-17875_rec_v1.bsp trj_orb_17874-17952_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_221001_230101_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 17318 2022-10-02T04:58:50.817 0.010 -0.004 0.006 17327 2022-10-03T15:08:50.817 -0.044 0.005 -0.006 17333 2022-10-04T13:02:50.817 -0.016 0.003 -0.003 17343 2022-10-06T00:38:50.817 0.004 -0.002 0.002 17354 2022-10-07T16:51:50.817 -0.002 0.001 -0.001 17362 2022-10-08T22:23:50.817 0.006 -0.003 0.004 17375 2022-10-10T22:23:50.817 0.025 -0.009 0.017 17390 2022-10-13T05:53:50.817 -0.013 0.002 -0.006 17408 2022-10-15T22:33:50.817 -0.005 0.002 -0.003 17412 2022-10-16T14:28:50.817 -0.003 0.000 -0.002 17419 2022-10-17T15:58:50.817 0.006 -0.001 0.004 17423 2022-10-18T06:12:50.817 0.001 -0.000 0.000 17428 2022-10-19T00:08:50.817 -0.015 0.006 -0.015 17435 2022-10-20T01:33:50.817 0.006 -0.002 0.005 17445 2022-10-21T14:38:50.817 0.003 -0.001 0.003 17456 2022-10-23T06:28:50.817 -0.002 0.001 -0.002 17465 2022-10-24T16:13:50.817 0.015 -0.003 0.015 17475 2022-10-26T05:22:50.817 -0.006 -0.000 -0.005 17487 2022-10-28T00:41:50.817 -0.002 0.001 -0.003 17500 2022-10-30T00:58:50.817 0.011 0.001 0.010 17510 2022-10-31T13:58:50.817 0.021 0.006 0.012 17519 2022-11-01T21:08:50.817 0.008 -0.003 0.009 17526 2022-11-02T23:23:50.817 -0.011 0.003 -0.016 17539 2022-11-04T23:59:50.817 -0.002 -0.001 -0.003 17557 2022-11-07T15:58:50.817 0.001 -0.001 0.001 17567 2022-11-09T04:28:50.817 0.009 -0.003 0.002 17578 2022-11-10T20:58:50.817 -0.008 0.003 -0.009 17586 2022-11-12T02:08:50.817 -0.018 0.007 -0.017 17593 2022-11-13T03:43:50.817 0.016 -0.006 0.015 17598 2022-11-13T23:08:50.817 -0.009 0.001 -0.019 17611 2022-11-15T21:08:50.817 -0.001 0.000 0.001 17617 2022-11-16T19:46:50.817 0.002 -0.000 0.003 17626 2022-11-18T04:16:50.817 -0.001 0.000 -0.000 17632 2022-11-19T02:28:50.817 -0.005 0.002 -0.007 17644 2022-11-20T22:28:50.817 -0.001 0.000 -0.002 17656 2022-11-22T19:18:50.817 -0.008 0.000 -0.022 17665 2022-11-24T02:48:50.817 -0.002 0.001 0.000 17673 2022-11-25T08:18:50.817 0.022 -0.009 0.030 17683 2022-11-26T21:53:50.817 -0.005 0.000 -0.015 17694 2022-11-28T14:08:50.816 -0.001 -0.001 -0.001 17704 2022-11-30T01:58:50.816 0.008 -0.003 0.022 17715 2022-12-01T18:28:50.816 -0.002 0.001 -0.008 17730 2022-12-04T01:28:50.816 -0.004 0.001 -0.018 17735 2022-12-04T20:23:50.816 0.005 0.001 0.020 17749 2022-12-06T21:48:50.816 -0.001 0.000 0.001 17761 2022-12-08T17:53:50.816 0.003 -0.001 0.004 17768 2022-12-09T19:11:50.816 -0.001 0.000 0.002 17779 2022-12-11T11:28:50.816 0.000 -0.000 -0.000 17788 2022-12-12T20:43:50.816 -0.000 0.000 -0.001 17800 2022-12-14T17:13:50.816 0.000 -0.000 0.002 17808 2022-12-15T21:23:50.816 -0.001 0.000 0.004 17815 2022-12-16T22:58:50.816 0.000 -0.000 -0.000 17822 2022-12-18T00:43:50.816 -0.000 0.000 0.000 17833 2022-12-19T17:43:50.816 -0.000 0.000 -0.003 17841 2022-12-20T21:48:50.816 0.001 -0.000 -0.007 17847 2022-12-21T19:58:50.816 -0.001 0.001 0.004 17854 2022-12-22T21:18:50.816 -0.000 0.000 0.004 17860 2022-12-23T19:28:50.816 0.000 -0.000 -0.000 17868 2022-12-25T01:28:50.816 -0.001 0.000 -0.024 17874 2022-12-26T00:13:50.816 -0.000 -0.000 -0.038 17889 2022-12-28T05:13:50.816 -0.000 0.000 0.000 17908 2022-12-31T03:33:50.816 0.001 -0.000 -0.013 End of comments.