Author:  AC Coordinator / AIUB/CODE

Ultra Rapid IGS Orbit Combination - Week 1223   Day: 0 Hour: 12  (Jun 15, 2003)

Contacts: R. Weber (rweber@luna.tuwien.ac.at),
          H. Bock (bock@aiub.unibe.ch),
          R. Dach (dach@aiub.unibe.ch)


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.


REMARKS on IGS Ultra Rapid Orbit Combination:


1. Starting on 02-Dec-2001 (GPS Week 1143, day 0, MJD 52245) all IGS
   products, including the IGS combined orbits, are based on the IGS
   realization of the ITRF2000 reference frame (IGS00). For more information
   see IGSMAIL #3605.

_______________________________________________________________________________


Table 1: Daily transformation of each centre to the combined IGS orbit and
         clocks. 

         WRMS - RMS weighted by the centres SP3 header accuracy codes.
         STA  - Number of stations in the daily solutions.
         Units: meters, mas, ppb, nano-sec, nano-sec/day.

Table 1.1223.0   GPS week: 1223   Day: 0   MJD: 52805.5

CENT STA|  DX   DY   DZ    RX    RY    RZ  SCL  RMS WRMS |   TOFT  TDRFT    RMS
--------|------------------------------------------------|---------------------
cou  n/a|0.00 0.00 0.01  0.02 -0.28  1.19 -0.2 0.19 0.30 |    1.0   -0.3   9.34
emu  n/a|0.00 0.00 0.00 -0.16 -0.15  0.46  0.0 0.07 0.06 |  203.4  -13.8   2.32
esu  n/a|0.00 0.00-0.02 -0.05  0.30 -0.44  0.4 0.15 0.11 | 3076.0   37.5   2.43
gfu  n/a|0.00 0.00 0.00  0.20  0.26 -0.43  0.0 0.09 0.07 |   -0.3    0.7   2.40
siu  n/a|0.00 0.00 0.00  0.07 -0.62  0.24 -0.5 0.26 0.26 |    0.0    0.0   0.00


Table 2: Daily fit for each satellite and each centre resulting from weighted
         average combination. 

         The last column gives the IGS resulting satellite accuracy measures 
         found in the IGS SP3 header. Eclipsing satellites are flagged with
         and "E" beside the PRN number. "X" stands for excluded from RMS, 
         WRMS and MEDIan- combination statistics but included in IGU orbit.
         "MEDI" stands for median of the centre's satellite RMS.

         Units: cm.

Table 2.1223.0   GPS week: 1223   Day: 0   MJD: 52805.5

        Weighted Average
 PRN  | cou emu esu gfu siu  IGU |
------|--------------------------|
   1E |  53  14  21  20  62   15 | 
   2  |   6   4   9  10  12    5 | 
   3  |   8   3  11   5  18    5 | 
   4  |  10   4  10  10  39    8 | 
   5  |   9   4   6   7  10    4 | 
   6  |  16   4  17   3  21    6 | 
   7  |   9   8  12  12  23    7 | 
   8  |  10   4  11   3   9    4 | 
   9  |   9   4   9   6  10    4 | 
  10  |  11   4  14   9  14    5 | 
  11E |  15   5  14  10  13    6 | 
  13E |  13   8  21  12  39   10 | 
  14E |  13   9  35  12  60   15 | 
 X15  | >>>   4 --- ---   8    5 | 
  16  |   6   4  13   9  16    5 | 
  17  |  56   5  10  11  24    7 | 
  18  |  11   8  11   3  27    6 | 
  20  |   8   9  24   4  11    7 | 
  21  |  11  10  10   6  20    6 | 
 X23  |  12   6 ---   4  16    5 | 
 X24  | 673 ---  10 ---  18   13 | 
  25  |   6   6  12   5  19    5 | 
 X26E |  10   7  16 ---  98   42 | 
  27  |  10   4  12   4  18    5 | 
  28  |   8   5   6   7  14    4 | 
 X29E |  12  15  36 ---  95   46 | 
  30  |   6   7   9   6  12    4 | 
  31  |   8   8  14   6   9    5 | 
------|--------------------------|
 RMS  |  19   7  15   9  26      | 
 WRMS |  30   6  11   7  26      |
 MEDI |  10   5  12   7  18      |