MAVEN Reconstructed SPK, NAV Solution, 2017-07-01 to 2017-10-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue Nov 14 16:16:34 PST 2017 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 5335 through 5827): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2017 JUL 01 00:01:09.184 2017 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_05317-05355_rec_v1.bsp trj_orb_05354-05383_rec_v1.bsp trj_orb_05382-05430_rec_v1.bsp trj_orb_05429-05441_rec_v1.bsp trj_orb_05439-05540_rec_v1.bsp trj_orb_05539-05573_rec_v1.bsp trj_orb_05573-05578_rec_v1.bsp trj_orb_05577-05584_rec_v1.bsp trj_orb_05583-05589_rec_v1.bsp trj_orb_05589-05595_rec_v1.bsp trj_orb_05594-05600_rec_v1.bsp trj_orb_05600-05605_rec_v1.bsp trj_orb_05605-05611_rec_v1.bsp trj_orb_05611-05616_rec_v1.bsp trj_orb_05615-05623_rec_v1.bsp trj_orb_05622-05648_rec_v1.bsp trj_orb_05647-05692_rec_v1.bsp trj_orb_05691-05729_rec_v1.bsp trj_orb_05728-05761_rec_v1.bsp trj_orb_05748-05805_rec_v1.bsp trj_orb_05804-05838_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_170701_171001_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 5337 2017-07-01T10:28:50.815 0.051 -0.024 0.085 5345 2017-07-02T23:58:50.815 -0.047 -0.006 -0.063 5354 2017-07-04T14:43:50.815 0.024 -0.010 0.012 5361 2017-07-05T23:58:50.816 0.029 -0.004 0.037 5371 2017-07-07T19:33:50.816 -0.014 0.007 0.000 5375 2017-07-08T13:33:50.816 0.011 -0.003 -0.004 5382 2017-07-09T23:38:50.816 -0.009 -0.001 -0.012 5392 2017-07-11T20:58:50.816 0.041 0.009 0.037 5398 2017-07-13T01:13:50.816 -0.022 -0.012 -0.004 5408 2017-07-14T19:58:50.816 0.004 -0.011 0.013 5411 2017-07-15T10:58:50.816 -0.010 -0.003 -0.008 5420 2017-07-17T01:58:50.816 0.063 -0.031 0.041 5423 2017-07-17T17:58:50.816 -0.054 -0.025 -0.028 5429 2017-07-18T18:38:50.816 -0.158 0.086 -0.088 5432 2017-07-19T09:43:50.816 -0.024 -0.000 -0.016 5439 2017-07-20T18:46:06.816 -0.008 -0.002 -0.002 5470 2017-07-26T11:58:50.816 0.029 -0.006 0.001 5486 2017-07-29T12:58:50.816 -0.137 0.053 -0.046 5496 2017-07-31T09:58:50.816 -0.062 0.033 -0.016 5515 2017-08-04T01:58:50.816 -0.096 -0.034 -0.026 5531 2017-08-07T01:58:50.816 -0.016 -0.008 -0.002 5536 2017-08-08T02:23:50.816 0.063 0.015 -0.010 5539 2017-08-08T14:09:20.816 -0.324 -0.043 -0.058 5544 2017-08-09T12:19:10.816 -0.118 0.009 -0.019 5546 2017-08-09T22:34:10.816 0.289 0.129 0.033 5556 2017-08-11T17:58:50.816 -0.124 0.039 -0.015 5562 2017-08-12T20:28:50.817 0.102 -0.045 0.009 5565 2017-08-13T10:58:50.817 -0.142 0.027 -0.014 5573 2017-08-14T23:38:06.817 -0.534 0.014 -0.029 5575 2017-08-15T06:58:50.817 0.162 -0.099 0.015 5576 2017-08-15T11:58:50.817 -0.392 0.195 -0.034 5577 2017-08-15T17:58:50.817 -0.221 -0.041 -0.005 5580 2017-08-16T07:58:50.817 -0.311 -0.122 0.005 5583 2017-08-16T18:58:50.817 0.324 -0.153 0.029 5586 2017-08-17T08:13:50.817 0.170 -0.074 0.015 5589 2017-08-17T21:58:50.817 -0.065 0.033 -0.006 5592 2017-08-18T11:48:50.817 -0.121 0.056 -0.008 5594 2017-08-18T20:58:50.817 0.321 -0.132 0.014 5597 2017-08-19T10:03:50.817 -0.217 0.106 -0.015 5600 2017-08-19T23:58:50.817 0.175 -0.054 0.002 5603 2017-08-20T12:58:50.817 -0.216 0.100 -0.009 5605 2017-08-20T21:58:50.817 0.117 -0.048 0.004 5608 2017-08-21T11:28:50.817 -0.284 0.103 -0.002 5611 2017-08-21T23:53:50.817 -0.305 0.148 -0.044 5613 2017-08-22T09:33:50.817 0.085 -0.034 0.001 5615 2017-08-22T17:58:50.817 0.067 -0.035 0.005 5618 2017-08-23T07:08:50.817 0.062 -0.033 0.007 5620 2017-08-23T15:59:16.817 -0.306 0.157 -0.034 5622 2017-08-24T02:58:50.817 -0.052 -0.017 0.009 5626 2017-08-24T17:58:50.817 0.027 -0.007 0.006 5631 2017-08-25T17:58:50.817 0.026 -0.002 -0.003 5640 2017-08-27T10:05:50.817 -0.088 -0.001 0.015 5647 2017-08-28T17:28:50.817 -0.004 -0.001 0.001 5653 2017-08-29T19:58:50.817 -0.013 -0.005 0.002 5659 2017-08-30T21:58:50.817 -0.092 0.013 0.015 5669 2017-09-01T17:58:50.817 0.136 -0.041 -0.013 5672 2017-09-02T07:58:50.817 -0.078 -0.004 0.020 5681 2017-09-03T23:58:50.817 0.009 0.002 -0.003 5691 2017-09-05T20:58:50.817 0.020 0.008 -0.010 5702 2017-09-07T19:58:50.817 0.024 -0.010 0.001 5716 2017-09-10T09:08:50.817 -0.009 0.003 -0.006 5723 2017-09-11T17:28:50.817 -0.003 -0.000 0.000 5728 2017-09-12T15:18:50.817 -0.038 0.016 -0.003 5735 2017-09-13T21:48:50.817 0.036 -0.019 0.019 5740 2017-09-14T21:13:50.817 0.001 -0.000 -0.000 5748 2017-09-16T09:28:50.817 0.016 0.004 -0.010 5754 2017-09-17T09:58:50.817 0.003 -0.002 0.002 5760 2017-09-18T13:33:50.817 0.000 -0.000 0.000 5766 2017-09-19T15:09:49.817 -0.003 0.001 -0.002 5769 2017-09-20T06:18:58.817 0.001 0.000 -0.001 5773 2017-09-20T21:58:50.817 0.010 -0.004 0.011 5776 2017-09-21T13:32:54.817 -0.024 -0.004 0.015 5784 2017-09-22T23:13:50.817 -0.001 0.001 -0.001 5791 2017-09-24T06:28:50.817 -0.010 0.005 -0.007 5799 2017-09-25T17:43:50.817 0.017 -0.009 0.019 5804 2017-09-26T17:58:50.817 0.012 0.003 -0.010 5814 2017-09-28T13:58:50.817 -0.011 -0.001 0.007 5823 2017-09-30T05:58:50.817 0.003 0.001 -0.001 End of comments.