Author: AC Coordinator / NOAA NGS sum-file Version 2.0 Rapid IGS Orbit Combination - Week 1508 Day: 6 (Dec 06, 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: igr15086.sp3 IGR GPS ephemeris in SP3 format. igr15086.clk IGR GPS satellite and station clocks in RINEX format. igr15086.cls IGR GPS clock combination summary report. igr15086.erp Earth Rotation Parameters (ERP) and their rates as well as Universal Time (UT1-UTC) and Length Of Day (LOD) associated with IGS ephemerides. igr15086.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 ----+--------+--------------- 6 | EMR | 9 6 | ESA | SYOG 6 | GFZ | 7 13 31 TIDB 6 | JPL | 9 FAIR HARB LPGS 5. 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 ----+--------+--------------- 6 | USN | 1 28 29 6. 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. 7. 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. 8. 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 1.1508.6 GPS week: 1508 Day: 6 MJD: 54806.000 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| -26 15 -38 91 82 -826-29.76 911 911 | -42 -51 2218 4410 cod 128| 1 0 -4 -27 19 -37 -.31 13 13 | -440 512 20 135 emr 45| -3 1 5 -78 -111 -37 .39 16 16 | 3903 -43 12 97 esa 95| 1 -3 -5 19 3 33 .23 13 13 | -977 1429 16 121 gfz 88| 0 0 1 -5 -13 -24 -.05 16 16 | -2 36 22 159 iga n/a| 2 0 -3 -14 30 225 -.18 12 10 | -58 201 60 148 igu n/a| 0 2 -8 197 -199 201 -.17 65 52 | 35 -476 2974 5973 jpl 45| -4 4 5 26 17 -22 .47 19 19 | 4830 0 22 196 ngs 97| 1 2 1 -8 -50 40 -.47 18 17 | -55 150 1997 3955 sio 70| 1 -1 2 35 90 73 -.38 21 19 | 0 0 0 0 usn 45| -2 -3 -7 157 175 -31 -.06 70 31 | 3640 13 71 1841 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 2.1508.6 GPS week: 1508 Day: 6 MJD: 54806.000 Weighted Average PRN | brd cod emr esa gfz iga igu jpl ngs sio usn IGR | ------+-------------------------------------------------------------+ X1 | 524 6 --- --- --- --- --- --- --- --- 267 0 | 2 | 841 15 21 16 18 11 31 19 17 19 41 7 | 3 | 766 9 8 8 15 9 76 12 13 9 20 4 | 4 | 372 8 14 7 9 7 19 13 10 19 40 5 | 5 | 664 10 12 7 14 8 35 12 16 18 26 5 | 6 | 1540 11 8 10 23 8 29 13 11 12 19 5 | 7E | 698 11 18 11 10 11 49 16 17 19 43 6 | 8E | 632 20 18 17 13 17 122 22 31 36 25 8 | 9E | 1428 17 17 15 18 15 88 17 21 37 37 8 | 10E | 1314 10 15 11 12 12 124 14 17 17 20 5 | 11 | 931 14 17 14 18 10 46 25 16 21 63 8 | 12 | 555 16 18 15 18 14 42 26 17 16 23 7 | 13 | 1053 11 14 17 16 9 12 25 15 20 37 6 | 14 | 1009 13 15 16 19 10 30 18 18 18 45 7 | 15 | 402 12 17 18 17 8 57 19 14 16 25 6 | 16 | 918 17 26 15 17 10 31 22 19 18 24 7 | 17 | 640 13 14 10 9 9 27 26 11 9 51 6 | 18E | 921 13 19 15 14 24 77 22 25 18 58 8 | 19 | 290 8 8 9 11 6 25 33 15 17 29 6 | 20E | 987 9 21 11 10 11 57 17 18 20 30 6 | 21 | 1095 14 15 15 17 10 38 21 15 21 37 7 | 22E | 543 11 19 16 14 9 25 18 13 14 29 6 | 23 | 938 14 22 16 14 12 43 16 18 20 43 7 | 24 | 1096 11 14 7 16 6 33 15 17 16 31 5 | 25E | 865 14 13 14 17 12 94 14 22 27 26 6 | 26 | 401 10 15 10 13 9 168 14 14 16 33 5 | 27E | 1587 18 17 14 17 14 115 19 28 37 31 8 | 28 | 1115 16 19 16 20 9 19 18 15 21 316 7 | 29 | 252 10 8 8 13 6 38 19 15 18 122 5 | 30 | 944 10 11 10 12 8 19 12 17 25 27 5 | 31E | 736 12 11 13 13 9 29 17 12 13 37 5 | 32 | 689 22 22 9 23 27 76 22 22 15 54 8 | ------+-------------------------------------------------------------+ RMS | 911 13 16 13 16 12 65 19 18 21 70 | WRMS | 911 13 16 13 16 10 52 19 17 19 31 | MEDI | 841 12 15 14 15 10 38 18 17 18 33 | 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 3.1508.6 GPS week: 1508 Day: 6 MJD: 54806.0 CENT| CLK EPO | BRUS | WILL | ----+----------+-------------------+-------------------+ cod | cod 3072 | 7 7 22 | 13 13 36 | emr | emr 2956 | 9 9 29 | 13 18 45 | esa | esa 2976 | 7 8 27 | 13 14 37 | gfz | gfz 2935 | 11 15 28 | 17 20 55 | igr | igr 2976 | 7 7 25 | 12 13 40 | jpl | jpl 2955 | 16 30 50 | 15 30 50 | 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 4.1508.6 GPS week: 1508 Day: 6 MJD: 54806.500 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 | -27 25 27 244 -10 | -1 14 emr uuuuu | 100 95 -158 118 18 | 41 44 esa uuuuu | -45 -61 236 -228 1 | 5 14 gfz uuuuu | 40 -8 -91 66 4 | 11 20 iga xxxxx | -33 14 59 63 5 | -9 16 igu xxxxx | 281 -220 579 -169 3 | -12 34 jpl uuuuu | -1 -35 -55 326 7 | -10 22 ngs uuuuu | 30 17 3 -261 -11 | 2 15 sio uuxxu | -161 11 -212 -369 -15 | 37 41 usn uuuuu | -12 -28 40 138 16 | 24 31