Author: AC Coordinator / NOAA NGS sum-file Version 2.0 Rapid IGS Orbit Combination - Week 1507 Day: 2 (Nov 25, 2008) Contacts: J. Ray (jim.ray@noaa.gov), J. Griffiths (jake.griffiths@noaa.gov) COMBINATION STRATEGY: --------------------- For a complete description of the combination strategy along with all tables and statistics, please refer to the IGS Final Combination reports posted on CDDIS within 13 days after the end of the GPS week. PRODUCT FILES: -------------- The Rapid Orbit files generated and uploaded into CDDIS @ NASA/GSFC are: igr15072.sp3 IGR GPS ephemeris in SP3 format. igr15072.clk IGR GPS satellite and station clocks in RINEX format. igr15072.cls IGR GPS clock combination summary report. igr15072.erp Earth Rotation Parameters (ERP) and their rates as well as Universal Time (UT1-UTC) and Length Of Day (LOD) associated with IGS ephemerides. igr15072.sum Combination summary report. REMARKS concerning the IGR Orbit Combination: --------------------------------------------- 1. Broadcast ("brd") orbits/clocks are included in the combination for statistics only. However broadcast clock corrections are used for clock alignment to GPS time and centre clock weight determination purposes. 2. The following center solutions (orbits/clocks) were excluded from the combination but kept for statistics: -> Centre: IGA IGU 3. The following centre clock solutions, which provide broadcast clock corrections, were excluded from the combination but kept in the combination statistics: -> Centre: NGS 4. The following clock solutions were excluded from the combination because they were biasing the combined clock solutions (clock shifts/outliers) but were kept for the RMS computation. All clocks from USN. Day | Centre | PRN/STA list ----+--------+--------------- 2 | COD | 8 31 YELL 2 | EMR | 9 27 HARB 2 | ESA | 8 JOZE SYOG TSKB 2 | GFZ | 7 2 | JPL | 9 25 PDEL 2 | USN | FAIR 5. New clock offsets and drifts were estimated for centres showing reference clock resets. Note that only the largest clock offset and drift are output to the summary file. However, the clock combination and the listed RMS include all the clock segments. In summary, the following clock shifts/resets were noticed and accounted for: Day | Centre | Time | Jump ----+--------+--------+------------- 2 | GFZ | ~22:00 | ~ -0.09 ns 6. The following orbit solutions were excluded from the combination because they were biasing the weighted average. They were still used for statistics computation unless all centres were excluded for the problem satellites in which case they were simply eliminated from the combination and statistics. The following table lists the exclusions: Day | Centre | PRN list ----+--------+--------------- 2 | USN | 1 7. Starting on 5-Nov-2006 (GPS Week 1400-0, MJD 54044) all IGS products, including the IGS combined orbits, are based on the IGS realization of the ITRF2005 reference frame (IGS05). For more information see IGSMAIL #5447. 8. Starting on 5-Nov-2000 (GPS Week 1087-0; mjd=51853) all IGS clock products are based on the new clock combination scheme which uses the the clock RINEX files as input if available, otherwise SP3 clocks are used. The navigation solution is still based on the SP3 clocks but this will soon adopt the clock RINEX files as well. 9. Starting on 5-Nov-2006 (GPS Week 1400, day 0, MJD 54044) the absolute antenna model is introduced (IGSMAIL #5272). The antenna phase center offsets and phase center variations are given in the file: ftp://igscb.jpl.nasa.gov/pub/station/general/igs05.atx ORBIT COMBINATION AND EVALUATION STATISTICS: -------------------------------------------- Table 1: Daily transformation of each centre to the combined IGR orbit and clocks (iga is the 24h adjusted part of Ultra Rapid, igu is the 24h predicted part of Ultra Rapid). WRMS - RMS weighted by the centres SP3 header accuracy codes. STA - Number of stations in the daily solutions. Table 1.1507.2 GPS week: 1507 Day: 2 MJD: 54795.000 CENT STA| DX DY DZ RX RY RZ SCL RMS WRMS| TOFT TDRFT SDEV RMS | [mm] [mm] [mm] [uas] [uas] [uas] [ppb] [mm] [mm]| [ps] [ps/d] [ps] [ps] --------+----------------------------------------------------+------------------------------ brd n/a| 7 0 99 -4049 -1918 -3929-25.99 1296 1296 | 685 -1090 2711 3868 cod 132| 0 1 -1 -39 29 6 -.36 13 12 | 524 -1296 24 158 emr 45| -3 0 1 -11 -61 19 .37 15 15 | 2222 -1187 12 92 esa 95| 1 0 -1 32 -4 -1 .14 14 14 | -683 685 18 127 gfz 97| 0 0 0 -50 -3 -82 -.07 15 15 | 515 -829 22 135 iga n/a| 2 2 0 -10 27 45 -.12 12 11 | 766 -1578 61 242 igu n/a| 7 3 -2 -149 337 -330 -.12 73 51 | 950 -5106 1832 3900 jpl 45| 0 1 3 59 30 56 .43 17 17 | 3761 -1078 17 224 ngs 109| 0 0 -1 2 -40 5 -.37 16 14 | 748 -1448 2243 3512 sio 71| 0 0 3 27 31 8 -.39 25 22 | 0 0 0 0 usn 46| 1 -3 -9 21 143 5 -.07 36 30 | 2704 -1262 93 1887 Table 2: Daily fit for each satellite and each centre resulting from weighted average combination. The last column gives the IGR resulting satellite accuracy measures found in the IGS SP3 header. Eclipsing satellites are flagged with "E" (or "M" for moon) beside the PRN number. "X" stands for excluded from RMS, WRMS and MEDI-combination statistics but included in IGU Units: mm Table 2.1507.2 GPS week: 1507 Day: 2 MJD: 54795.000 Weighted Average PRN | brd cod emr esa gfz iga igu jpl ngs sio usn IGR | ------+-------------------------------------------------------------+ X1 | 2108 6 --- --- --- --- --- --- --- --- 343 0 | 2 | 1196 12 17 14 17 10 32 18 13 32 26 6 | 3 | 1379 8 10 7 15 7 25 13 16 17 21 4 | 4 | 596 11 14 12 12 10 21 16 11 15 24 5 | 5 | 1928 11 11 10 11 7 30 12 10 20 27 5 | 6 | 1741 8 8 8 18 6 29 13 13 12 25 4 | 7E | 1875 14 14 13 15 8 44 21 15 21 72 7 | 8E | 804 20 15 23 14 35 163 21 24 56 36 9 | 9E | 2027 18 13 21 16 19 212 16 22 36 20 7 | 10 | 913 11 14 11 13 11 135 13 12 18 24 5 | 11 | 1410 12 17 12 18 9 22 18 17 21 44 6 | 12 | 561 16 13 18 20 10 34 17 12 28 33 7 | 13 | 1155 12 16 16 15 11 33 17 14 22 37 6 | 14 | 1085 14 14 17 17 10 29 20 14 16 58 7 | 15 | 852 12 14 17 19 10 49 14 12 21 24 6 | 16 | 1205 15 20 18 20 11 41 18 19 32 36 7 | 17 | 549 11 10 11 11 8 47 20 18 15 35 5 | 18 | 1319 16 21 15 15 13 32 19 13 15 49 7 | 19 | 980 11 12 11 16 8 30 17 14 18 32 5 | 20 | 1664 10 18 20 11 10 29 18 18 17 35 6 | 21 | 740 12 16 12 13 10 20 12 12 15 42 5 | 22 | 648 12 18 16 16 12 38 19 14 16 29 6 | 23 | 818 12 20 21 13 13 44 20 15 16 36 7 | 24 | 2285 10 13 9 14 10 25 11 12 26 24 5 | 25E | 1202 17 17 14 14 17 210 15 23 43 39 8 | 26 | 1510 8 11 7 17 7 22 9 10 13 23 4 | 27E | 1386 22 19 11 14 13 32 19 22 40 45 8 | 28 | 1245 16 15 16 20 15 61 19 19 24 40 7 | 29 | 1391 12 9 6 9 9 35 15 10 15 26 4 | 30 | 935 6 10 6 12 8 41 9 11 30 27 5 | 31E | 897 13 16 16 15 12 28 25 15 25 37 7 | 32 | 1424 10 19 12 18 11 36 20 18 14 48 7 | ------+-------------------------------------------------------------+ RMS | 1295 13 15 14 15 12 73 17 16 25 36 | WRMS | 1295 12 15 14 15 11 51 17 14 22 30 | MEDI | 1202 12 14 13 15 10 33 17 14 20 35 | Table 3: Daily Precise Navigation Summary using the corresponding Centre orbit positions and satellite clock corrections at 15 min intervals. Each line gives the daily station RMS w.r.t. the estimated coordinates for the Latitude, Longitude and Height components. CLK - Satellite clocks used. EPO - Number of satellite clock epochs available for that day. Units: mm Table 3.1507.2 GPS week: 1507 Day: 2 MJD: 54795.0 CENT| CLK EPO | BRUS | TOW2 | WILL | ----+----------+-------------------+-------------------+-------------------+ cod | cod 3071 | 9 10 26 | 11 15 43 | 9 9 26 | emr | emr 2960 | 10 9 34 | 13 18 76 | 23 17 33 | esa | esa 2976 | 10 9 33 | 10 16 43 | 18 11 31 | gfz | gfz 2951 | 8 10 37 | 12 12 48 | 17 20 52 | igr | igr 2966 | 9 9 33 | 11 16 65 | 20 14 32 | jpl | jpl 2958 | 60 22 44 | 11 14 57 | 27 23 41 | Table 4: Earth Orientation Parameters daily summary. Daily Centre ERP, ERP Rates and LOD differences with respect to IGR combined values. Xpole,Xrt: x pole and x pole rate Ypole,Yrt: y pole and y pole rate LOD : Length Of Day AC LOD BIAS : 21-day mean LOD bias with respect to Bulletin A AC LOD BIAS RMS: RMS of AC LOD BIAS FLAG: "u" (used), "x" (excluded), "-" (no submission) for Xpole, Ypole, Xrt, Yrt and LOD A star ("*") beside the AC name indicates that AC LOD values were derived from AC UT1-UTC values. Table 4.1507.2 GPS week: 1507 Day: 2 MJD: 54795.500 AC LOD AC LOD CENT FLAG | Xpole Ypole Xrt Yrt LOD | BIAS BIAS RMS | [uas] [uas] [uas/d] [uas/d] [us]| [us] [us] ------------+----------------------------------------+------------------ cod xxxxx | -36 28 221 144 -2 | 6 27 emr uuuuu | 61 53 -318 82 4 | 42 51 esa uuuuu | -36 -58 21 -155 -2 | 13 29 gfz uuuuu | -27 48 150 -115 -3 | 20 31 iga xxxxx | -27 -13 114 -49 -6 | 3 26 igu xxxxx | -342 -144 -304 -249 18 | 21 83 jpl uuuuu | 34 -44 -102 360 5 | -12 34 ngs uuuuu | 29 -15 226 -139 5 | 10 36 sio uuxxu | -24 5 -24 136 -11 | 44 52 usn uuuux | -166 45 233 -28 60 | 5 53