From James Thu Jan 28 00:00:00 1993 From: James (James) Date: 28 Jan 1993 00:00:00 Subject: [IGSMAIL-186] JPL Epoch '92 Re-analysis Message-ID: From: James F Zumberge Subject: JPL Epoch '92 Re-analysis ----------------------------------- Submitted by J F Zumberge, G Blewitt, M B Heflin, D C Jefferson, F H Webb all at the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109. The following files have been posted on BODHI (for access to BODHI contact starr at logos.jpl.nasa.gov): ______________________________________________________________________________ filename contents ______________________________________________________________________________ jplepoch92.sum This text file. jplepoch92.erp Earth rotation parameters for Epoch '92. jplepoch92.sp1 GPS ephemerides for Epoch '92, sp1 format. jplepoch92.sp3 " " " " " , sp3 " . ______________________________________________________________________________ These files contain the results of our re-analysis of the Epoch '92 period, 1992 Jul 26 through 1992 Aug 07, with our most recent analysis strategy. Because of AS, the days of Aug 1, Aug 2, and Aug 8 were not analyzed. This submission resembles a normal weekly one. In the UTPM table, the UT1R-UTC column contains the assumed nominal values from IERS Bulletin-B finals (_not_ predicts). The new polar motion estimates differ from the original "near-real-time" values as indicated in the following table: delta X (mas) delta Y (mas) average 0.07 -0.43 st deviation 0.40 0.30 Shown below is a comparison of the new ephemerides with the original ones. Actually, the comparison is with the cleansed originals (refer to IGS Message Nos. 127 and 164), and explains the absence of an entry for prn 15 on Jul 26. Each entry in the table represents, for the indicated prn and day, the 3d rss difference over 24 hours between the current Epoch '92 analysis and the original analysis. The ~3.5-m 3d-rss difference for Jul 26-30 changes abruptly to ~1.1 m on Jul 31, because of a change in the nominal earth-orientation values in the original processing (caused by an update in the IERS B predicts), and because the original processing used the nominal (not solved-for) earth orientation in the transformation from inertial to earth-fixed coordinates. The values used on Jul 31 and later for the original analysis are very close to the IERSB Final values used in the current re-analysis. The ~1.1-m comparison for Jul 31 and later (with some exceptions, to be discussed), is due mainly to the change in convention from referring to the antenna phase center (our original convention) to the spacecraft center of mass (the current convention). The comparison for Monday, Aug 3 shows mixed results. Because A-S was in effect for the first 10 hours of this day, cross-correlated data from Block-II satellites were not used, as reflected in the data availability tables at the end of this file. Because the comparisons are over a 24-hr period, some of the Block-II results come from extrapolations. For example, the value of 9.2 m for prn 25 becomes 1.3 m if differences before 10 am are excluded. Finally, the outlier of 26.6 m from prn 15 on Aug 6 is a result of our deweighting data from that prn and day in our original submission. It is modeled perfectly well with the current estimation strategy. COMPARISON OF EPOCH '92 ORBITS WITH ORIGINAL "NEAR-REAL-TIME" ORBITS 92 7 26 92 7 27 92 7 28 92 7 29 92 7 30 92 7 31 prn 3d rss (m) 2 3.6 3.6 3.6 3.6 3.7 1.1 3 3.4 3.6 3.6 3.6 3.8 1.0 11 3.5 3.5 3.7 3.8 3.8 1.0 12 3.7 3.7 3.7 3.8 3.9 1.0 13 3.6 3.4 3.7 3.8 3.8 1.0 14 3.4 3.6 3.6 3.7 3.8 1.1 15 3.5 3.7 3.9 3.8 1.0 16 3.5 3.6 3.6 3.8 3.8 1.1 17 3.2 3.3 3.3 3.4 3.5 1.1 18 3.4 3.5 3.5 3.6 3.7 1.1 19 3.4 3.4 3.5 3.6 3.6 1.0 20 3.5 3.6 3.6 3.7 3.8 1.2 21 3.5 3.4 3.4 3.6 3.7 1.1 23 3.5 3.5 3.6 3.7 3.7 1.1 24 3.3 3.3 3.4 3.5 3.6 1.0 25 3.4 3.5 3.5 3.7 3.8 1.0 28 3.5 3.5 3.6 3.7 3.8 1.1 92 8 3 92 8 4 92 8 5 92 8 6 92 8 7 prn 2 2.4 1.1 1.1 1.1 1.1 3 0.9 0.9 0.9 1.0 0.9 11 1.0 1.0 1.0 1.0 1.0 12 1.0 1.0 1.0 1.0 1.0 13 1.0 1.0 1.0 1.0 1.0 14 1.1 1.0 1.1 1.1 1.1 15 1.1 1.1 1.1 26.6 1.1 16 4.6 1.0 1.0 1.0 1.1 17 1.8 1.1 1.1 1.1 1.1 18 1.1 1.1 1.2 1.1 1.2 19 1.1 1.1 1.1 1.1 1.1 20 5.5 1.1 1.1 1.2 1.2 21 4.0 1.1 1.1 1.1 1.0 23 3.6 1.1 1.1 1.2 1.1 24 1.6 1.2 1.2 1.1 1.1 25 9.2 1.0 1.1 1.1 1.1 28 5.2 1.1 1.1 1.1 1.1 END COMPARISON OF EPOCH '92 ORBITS WITH ORIGINAL "NEAR-REAL-TIME" ORBITS JPL LODR TABLE Epoch '92 (1992 Jul 26 - Aug 07) MJD LODR +/- (ms/day) 48829.5 1.54 0.05 48830.5 1.55 0.05 48831.5 1.52 0.05 48832.5 1.24 0.05 48833.5 1.42 0.05 48834.5 1.44 0.05 48837.5 1.44 0.07 48838.5 1.86 0.05 48839.5 1.89 0.05 48840.5 1.90 0.05 48841.5 1.75 0.05 END LODR TABLE NOTE: In the following table, UT1R-UTC are the assumed nominal values from IERS Bulletin-B finals; estimated LODR values are given in the previous table. See IGS Mail Message 97 for details. JPL UTPM TABLE Epoch '92 (1992 Jul 26 - Aug 07) MJD X Y UT1R-UTC XSIG YSIG UTSIG RMS XYC STA SAT '' '' sec '' '' sec 48829.5 -.09972 .43566 .40824 .00013 .00015 .00000 .0 .00 29 18 48830.5 -.09792 .43761 .40681 .00013 .00014 .00000 .0 .01 29 18 48831.5 -.09581 .43903 .40540 .00014 .00015 .00000 .0 -.03 29 18 48832.5 -.09443 .44105 .40398 .00014 .00014 .00000 .0 .01 28 18 48833.5 -.09255 .44300 .40254 .00013 .00014 .00000 .0 .03 29 18 48834.5 -.09007 .44511 .40105 .00013 .00014 .00000 .0 .04 29 18 48837.5 -.08291 .45154 .39646 .00028 .00031 .00000 .0 -.04 29 18 48838.5 -.08187 .45416 .39489 .00013 .00014 .00000 .0 .01 29 18 48839.5 -.08015 .45586 .39329 .00014 .00015 .00000 .0 -.03 29 18 48840.5 -.07820 .45779 .39166 .00014 .00015 .00000 .0 .01 28 18 48841.5 -.07643 .45993 .39001 .00015 .00017 .00000 .0 .03 28 18 END UTPM TABLE The following table indicates the "3-dimensional orbit repeatability", as defined in IGS Mail Message 37, for the Epoch '92 period, 1992 Jul 26 - Aug 07: ["3d rss" = sqrt(xrms**2 + yrms**2 + zrms**2)] JPL ORBIT REPEATABILITY TABLE Epoch '92 (1992 Jul 26 - Aug 07) 92 7 26 92 7 27 92 7 28 92 7 29 92 7 30 92 7 31 prn 3d rss (m) 2 0.3 0.20 0.57 0.51 0.35 0.4 3 0.2 0.28 0.45 0.42 0.48 0.5 11 0.3 0.30 0.64 0.46 0.30 0.2 12 0.2 0.33 0.47 0.43 0.27 0.1 13 0.3 0.33 0.35 0.39 0.24 0.2 14 0.3 0.47 0.41 0.36 0.32 0.3 15 0.9 0.54 0.87 0.86 0.69 0.4 16 0.1 0.21 0.21 0.25 0.26 0.3 17 0.2 0.15 0.26 0.20 0.32 0.3 18 0.3 0.34 0.41 0.40 0.53 0.4 19 0.3 0.23 0.38 0.57 0.22 0.3 20 0.2 0.27 0.24 0.28 0.29 0.4 21 0.3 0.39 0.69 0.27 0.20 0.1 23 0.3 0.31 0.37 0.37 0.26 0.3 24 0.3 0.28 0.20 0.26 0.40 0.3 25 0.2 0.30 0.31 0.62 0.76 0.6 26 0.6 0.28 0.40 0.43 0.44 0.3 28 0.2 0.30 0.29 0.27 0.28 0.2 92 8 3 92 8 4 92 8 5 92 8 6 92 8 7 prn 2 0.4 0.22 0.19 0.22 0.2 3 0.1 0.24 0.31 0.37 0.2 11 0.2 0.27 0.17 0.15 0.1 12 0.4 0.41 0.38 0.37 0.5 13 0.3 0.32 0.33 0.31 0.3 14 0.3 0.32 0.31 0.22 0.3 15 0.4 0.89 0.60 0.31 0.3 16 0.2 0.30 0.12 0.26 0.3 17 0.2 0.21 0.15 0.28 0.2 18 0.5 0.47 0.43 0.56 0.6 19 0.5 0.48 0.37 0.42 0.2 20 0.4 0.51 0.23 0.36 0.3 21 0.3 0.32 0.23 0.23 0.1 23 0.2 0.34 0.34 0.31 0.2 24 0.2 0.29 0.27 0.26 0.3 25 0.1 0.52 0.46 0.25 0.3 26 0.4 0.38 0.26 0.48 0.4 28 0.2 0.28 0.26 0.29 0.2 END ORBIT REPEATABILITY TABLE As described in IGS Mail Message 37, the following table compares the JPL precise ephemerides with those from the broadcast ephemeris: JPL COMPARISON OF BROADCAST NAVIGATION MESSAGE WITH PRECISE EPHEMERIDES 92 7 26 92 7 27 92 7 28 92 7 29 92 7 30 92 7 31 prn 3d rss (m) 2 4.3 4.7 3.5 3.7 4.0 3.7 3 10.1 10.1 9.8 9.7 9.6 9.5 11 7.4 4.6 3.7 8.8 10.1 5.7 12 10.0 8.4 8.5 10.7 13.3 14.2 13 8.69 8.1 6.7 5.97 10.3 6.6 14 4.5 7.2 8.1 4.4 4.4 5.9 15 6.1 8.9 9.7 9.8 9.7 5.8 16 8.0 10.7 8.8 6.7 7.3 7.1 17 4.6 5.4 9.2 7.3 7.9 6.1 18 4.5 4.7 4.8 4.7 5.1 4.1 19 6.5 4.8 2.9 2.5 4.5 5.0 20 3.7 3.5 4.5 3.7 5.2 4.9 21 5.3 5.4 4.0 5.3 7.3 6.4 23 11.9 10.4 5.8 3.7 3.4 4.4 24 14.4 14.5 14.9 16.1 15.9 14.3 25 7.0 7.4 9.8 14.7 14.3 8.9 26 24.5 22.5 20.3 20.0 14.2 20.0 28 3.3 2.9 3.4 3.5 3.0 3.7 92 8 3 92 8 4 92 8 5 92 8 6 92 8 7 prn 2 3.6 3.8 4.8 5.3 5.3 3 8.1 12.9 8.4 9.7 13.3 11 8.1 9.5 8.7 7.6 7.8 12 8.1 13.1 7.5 22.0 7.8 13 6.6 7.1 6.0 8.3 9.8 14 8.2 8.1 7.5 6.5 7.1 15 8.0 7.5 6.2 5.3 5.6 16 7.0 8.5 8.2 11.3 9.4 17 6.1 8.4 6.5 6.0 5.5 18 3.5 4.5 5.0 6.3 9.5 19 3.7 3.5 4.1 3.7 3.8 20 3.6 3.6 4.4 6.0 3.3 21 8.2 8.3 6.9 5.4 4.1 23 3.3 7.4 9.5 8.2 7.3 24 11.4 10.8 10.6 11.1 12.3 25 7.6 11.7 12.0 9.3 9.9 26 9.3 8.1 7.6 9.1 5.3 28 2.6 3.1 4.0 2.8 2.9 END COMPARISON OF BROADCAST NAVIGATION MESSAGE WITH PRECISE EPHEMERIDES The following table, as explained in IGS Report No. 99, indicates the amount of data from each tracking site used in the Epoch '92 analysis: JPL GROUND STATION INCLUSION TABLEs Epoch '92 (1992 Jul 26 - Aug 07) 92 7 26 92 7 27 92 7 28 92 7 29 92 7 30 92 7 31 ALBH 93 95 92 93 95 89 ALGO* 97 94 86 79 78 82 CANB 69 93 93 93 94 93 FAIR* 98 98 92 90 98 99 GOLD 78 87 0 89 92 88 HART* 91 92 76 91 92 88 HERS 82 83 81 82 82 77 JPLM 92 94 91 90 98 93 KOKB* 92 89 88 90 94 94 KOSG 90 88 83 88 91 90 MADR* 58 90 90 91 84 86 MASP 96 99 96 99 99 94 MATE 91 91 90 90 91 87 MCMU 77 99 102 108 108 107 METS 95 98 96 98 100 95 NALL 72 0 70 74 0 84 ONSA 95 84 89 90 91 92 PAMA 83 84 79 80 82 81 PENT 97 97 94 95 96 97 PINY 95 95 94 96 98 99 RCM2 94 96 90 91 94 65 SANT* 91 92 92 0 91 90 STJO 94 93 91 94 96 90 TAIS 84 85 81 82 72 77 TROM* 107 109 106 106 107 107 USUD 0 10 0 0 0 54 WETB 91 91 27 0 0 82 YAR1* 91 90 86 89 91 90 YELL 101 98 101 101 102 98 92 8 3 92 8 4 92 8 5 92 8 6 92 8 7 ALBH 70 97 97 97 96 ALGO* 58 88 85 90 89 CANB 62 86 93 92 92 FAIR* 72 98 99 100 94 GOLD 63 77 46 47 45 HART* 52 88 87 88 86 HERS 0 83 83 83 78 JPLM 68 93 95 96 92 KOKB* 69 94 93 94 90 KOSG 64 91 91 91 90 MADR* 49 87 87 82 64 MASP 61 89 10 0 0 MATE 59 83 85 91 87 MCMU 80 109 109 109 108 METS 70 101 101 101 96 NALL 0 49 0 103 110 ONSA 57 94 90 82 97 PAMA 63 91 92 43 0 PENT 68 98 100 99 99 PINY 68 99 98 96 90 RCM2 54 91 92 92 88 SANT* 0 92 92 92 88 STJO 63 94 96 96 90 TAIS 56 85 0 87 87 TROM* 76 107 106 107 103 USUD 47 86 85 89 65 WETB 63 91 92 92 87 YAR1* 69 80 92 93 94 YELL 71 98 101 104 97 _______________________ *Indicates fiducial site. END GROUND STATION INCLUSION TABLEs