[IGSMAIL-5712]: IGS Ultra Combination (IGU): 1466 2 18 (Resubmission Resubmission)

Jim Ray IGS.ACC at noaa.gov
Wed Feb 13 04:49:34 PST 2008


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IGS Electronic Mail      13 Feb 04:49:41 PST 2008      Message Number 5712
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Author:  AC Coordinator / NOAA NGS

sum-file Version 2.0
Ultra Rapid IGS Orbit Combination - Week 1466  Day: 2  Hour: 18  (Feb 12, 2008)

Contacts: J. Ray       (jim.ray at noaa.gov),
          J. Griffiths (jake.griffiths at 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:

igu14662_18.sp3   IGR GPS ephemeris in SP3 format.
igu14662_18.erp   Earth Rotation Parameters (ERP) and their rates as well as
                  Universal Time (UT1-UTC) and Length Of Day (LOD) associated 
                  with IGS ephemerides.
igu14662_18.sum   Combination summary report.

    
REMARKS concerning the IGU Orbit Combination:                                  
---------------------------------------------

 1. The following centre clock solutions, which provide broadcast and/or 
    predicted clock corrections, were excluded from the combination but kept 
    in the combination statistics:
    
             -> Centre: GOU COU 

 2. 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:
    
                Centre | PRN list
               --------+---------------
                  USU  |  15  15  15

 3. The following orbit solutions were excluded from the combination because
    less than 3 ACs have submitted results for given satellite(s).
    The following table lists the exclusions:
    
                Centre | PRN list
               --------+---------------
                  COU  |  32 

 4. 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.

 5. 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 IGU orbit
         and clocks. 
         
         WRMS - RMS weighted by the centres SP3 header accuracy codes.
         STA  - Number of stations in the daily solutions.
   
Table 1.1466.2   GPS week: 1466   Day: 2   MJD: 54508.750                            

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]
--------+----------------------------------------------------+------------------------------
cou   76|    0     0     4   -19   -24   210  -.18   27   26 |       0       0    ---   5867
emu   46|    0     0     1   -88    24     0   .13   14   12 |     976    -763    ---   3095
esu   40|   -3     2    -1   -34  -116   -34   .19   31   31 |    2642    -208    ---   2953
gfu   65|   -1     0     1   174   -26  -318  -.09   53   50 |     262    5703    ---   2885
gou   80|    2     0    -5    51    -7   -56  -.08   18   17 |     931     532    ---   9122
siu   62|    0    -2     0   304   130  -337  -.01   73   69 |       0       0    ---      0
usu   32|    2    -1     4    32   279   249  -.05   83   68 |     201     173    ---   3046



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

         The last column gives the IGU 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 2.1466.2   GPS week: 1466   Day: 2   MJD: 54508.750                            

        Weighted Average                        
 PRN  |  cou  emu  esu  gfu  gou  siu  usu  IGU |
------+-----------------------------------------+
   1  |   21   11   24   75   14  101   70   13 |
   2  |   26   17   20   81   13   97   84   15 |
   3  |   32   14   24   44   16   75   83   13 |
   4  |   27   10   24   48   17   67   63   11 |
   5  |   25   12   29   32   11   56   62   10 |
   6  |   23   13   21   32   18   61   44    9 |
   8  |   26   11   27   40   25   87   62   12 |
   9  |   25   11   25   72   18   72   94   14 |
  10  |   23   12   34   52   18   61   75   12 |
  11  |   28   13   49   43   20   84   52   13 |
  12E |   36   27   43   51   22   79   57   14 |
  13  |   27   12   25   42   13   58   52   10 |
  14  |   22   13   24   48   14   54   78   11 |
  15  |   24   12   30   43   19   75  265   11 |
  16E |   31   13   33   86   22   67   52   14 |
  17  |   34   13   37   33   15   69   93   13 |
  18  |   23   16   28   29   16   42   54   10 |
  19  |   44   13   31   76   16   48   94   15 |
  20  |   19   14   39   54   19   73   45   12 |
  21  |   31   16   24   31   27   39   72   12 |
  22  |   21   12   27   31   18   44   77   11 |
  23  |   27   11   20   46   11   67   49   10 |
  24  |   21    9   32   42   19   64   63   11 |
  25  |   25   12   17   37   12   71   77   11 |
  26  |   21   12   38   56   22   81   48   12 |
  27  |   26   12   23   38   16   69   97   13 |
  28E |   21   11   30   68   13  137   59   14 |
 X29  |   24  ---   41   57  ---  ---  ---   26 |
  30  |   25   19   51   53   17   73   61   14 |
  31  |   25   13   40   67   15   72   53   13 |
 X32  | ----  ---  ---  ---  ---  ---  ---    0 |
------+-----------------------------------------+
 RMS  |   27   14   31   53   18   73   83      |
 WRMS |   26   12   31   50   17   69   68      |
 MEDI |   25   12   28   46   17   69   63      |



Table 3: Earth Orientation Parameters daily summary.                           
                                                                              
         Daily Centre ERP, ERP Rates and LOD differences with respect to       
         IGU 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.                                       
                                                                              
         Remark: COU submits ERP-products for 00 and 12 UT only,               
                 for 06 and 18 UT extrapolations are used.                            


Table 3.1466.2   GPS week: 1466   Day: 2   MJD: 54508.250
                                                         AC LOD  AC LOD
CENT  FLAG  |   Xpole   Ypole     Xrt     Yrt    LOD |    BIAS  BIAS RMS
            |   [uas]   [uas]   [uas/d] [uas/d]  [us]|    [us]    [us]
------------+----------------------------------------+------------------
cou   uuuuu |      67     -86     228      92     -2 |      17     25
emu   uuuuu |      -1      91       1     203    -11 |      -7     21
esu*  uuuuu |     138     -55    -255    -208    -10 |     -15    108
gfu   uxuuu |    -208    -696    -107    -905     -6 |     -27     36
gou   uuuuu |       0      16      -8      80     12 |     -11     28
siu   uuuuu |     -84    -215    -232    -540     45 |      55     63
usu   uuuuu |    -294      -8     138      40      2 |      -7     19

Table 3.1466.3   GPS week: 1466   Day: 3   MJD: 54509.250
                                                         AC LOD  AC LOD
CENT  FLAG  |   Xpole   Ypole     Xrt     Yrt    LOD |    BIAS  BIAS RMS
            |   [uas]   [uas]   [uas/d] [uas/d]  [us]|    [us]    [us]
------------+----------------------------------------+------------------
cou   uuuuu |     119     421    -158    -215    134 |      17     25
emu   uuuuu |    -126     121     -63     196    190 |      -7     21
esu*  uuuuu |     -44     -85    -563    -330    146 |     -15    108
gou   uuuuu |     162    -312     448      99     35 |     -11     28
siu   uuuuu |    -495    -667    -323     -95     77 |      55     63
usu   uuuuu |    -142      81     217      45   -250 |      -7     19



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