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[IGSREPORT-16501] Wk 1489 IGS SINEX Combination



******************************************************************************
IGS Electronic Report   06 Aug 18:46:30 PDT 2008      Message Number 16501
******************************************************************************

Author:  R. Ferland, M. Piraszewski

===============================================================
 Combined AC solution for GPS week 1489 - 08/07/20 to 08/07/26
===============================================================

1) Contacts:
============
e-mail: rferland @ nrcan.gc.ca
Tel:    (613)995-4002 (Remi Ferland)
Fax:    (613)995-3215

2) Products:
============
All products are available at:
  CDDIS (cddis.gsfc.nasa.gov) and SOPAC (garner.ucsd.edu)

igs08P1489.snx  Combined weekly solution. 
igs08P1489.erp  Daily Earth Rotation Parameters.
igs00p03.erp    Daily Earth Rotation Parameters since GPS week 860. 
IGS08P30.snx    Cumulative Combined solution. 
igs08P1489.sum  This file.
igs08P1489.itr  Residuals between the AC and the IGS05 for the RF stations. 
igs08P1489.res  Residuals between the AC and the Combined Weekly solution.
IGS08P30.res    Residuals between the AC and the Cumulative Combined solution.
 
Where IGSyyPww & igsyyPwwww represent:
      yy      Last 2 digits of the year
      ww      week in year yy
      wwww    GPS week
      P       GPS technique used
 

3) Combination Strategy:
========================

     The AC solutions are processed using the following procedure:

3-1) The AC solutions are checked/corrected for possible format problems,
     station names inconsistencies, etc...
3-2) The AC solutions are unconstrained according to the information provided
     in the SOLUTION/APRIORI Block.
3-3) The AC solutions are aligned (using a 7-parameters) and compared to the
     IGS05 stations at the current epoch.
     ftp://igscb.jpl.nasa.gov/igscb/station/coord/IGS05.snx
3-4) The AC are compared to IGS05, to each other, to the previous week
     solution and to the cumulative solution in order to identify and remove
     outliers.
3-5) The weekly AC solutions are combined and added to the cumulative
     combined solution. The cumulative combination is done to ensures 14
     parameters singularity.

     The weekly combined solution is aligned to the IGS05 of the current
     epoch using a 7-parameters transformation. The singular cumulative
     combined solution is aligned to the IGS05 of the reference epoch
     using a 14-parameters transformation and the 132 ITRF station positions
     and velocities. The IGS05 is a realization of ITRF2005.

     For more details, see:
     Blewitt, G., C. Boucher and J. Kouba, 1997, Procedure for ITRF continuous
       realization, the report of the IGS GB, presented to the IGS Governing
       Board Meeting held in San Francisco, Dec. 11.
     Kouba, J., J. Ray and M.M. Watkins, IGS Reference Frame Realization, 1998
       IGS Analysis Center Workshop Proceedings, European Space Operations
       Centre, Darmstadt, Germany.

The combination software was developed at NRCan.

4) Remarks:
===========

     ITR = IGS05.snx
     igs = igs08P1489.snx
     IGS = IGS08P30.snx

     BuA = IERS Bulletin A

     grg ncl are used to quality control the weekly combination.
     gfz excluded from the geocenter estimation (Sec. 5-4).

     Solutions with manual station deletion:
         From the original solution:
             cod  SATA  X  Y  Z
             emr  SATA  X  Y  Z
             gfz  SATA  X  Y  Z
             MIT  SATA  X  Y  Z
             sio  SATA  X  Y  Z
             mit  SATA  X  Y  Z
         After unconstraining:
             esa  SELE
             MIT  SELE
             ngs  SELE  URUM
             sio  AUCK  SELE
             grg  FAIR  NTUS  YSSK
             ncl  GOUG  MAC1  YSSK

     4-1) Starting with GPS week 1400, the solutions are aligned to the
          IGS05.snx realization of ITRF2005.

     4-2) Starting with GPS week 1078, UT1-UTC from IERS Bulletin A
          is included in the erp files.

     4-3) Starting with GPS week 1412, the accumulated ERP file has been
          changed from "igs00p02.erp" to "igs00p03.erp". The main changes
          are:
       1) Correction of the pole position from IGb00 to IGS05 using the
          transformation in:
             http://igscb.jpl.nasa.gov/mail/igsmail/2006/msg00178.html
       2) Marginal ERP's in GPS week 1161 were replaced by reprocessed
          values.

5) Results:
===========

5-1)      AC (Variance Factor)^0.5 estimates:
=============================================
           The residuals used in the estimation of the Variance Factor
           are the differences between the cumulative combined solution
           and each AC weekly solution.
           SF = (Variance Factor)^0.5 = (Chi^2/dof)^0.5
           Final(SF) = Apriori(SF) * Aposteriori(SF)

Solution       |# sta| #RF |    Apriori(SF)|Aposteriori(SF)|      Final(SF)|
---------------|-----|-----|---------------|---------------|---------------|
cod            | 195 |  85 |        19.111 |         1.000 |        19.111 |
esa            | 117 |  65 |         4.448 |         1.000 |         4.448 |
emr            |  72 |  46 |         4.530 |         1.000 |         4.530 |
gfz            | 199 |  89 |        13.223 |         1.000 |        13.223 |
jpl            | 123 |  65 |         5.775 |         1.000 |         5.775 |
MIT            | 259 |  95 |         2.100 |         1.000 |         2.100 |
ngs            | 232 |  95 |        34.217 |         1.000 |        34.218 |
sio            | 246 |  92 |         2.281 |         1.000 |         2.281 |
grg            |  78 |  49 |        13.801 |         1.000 |        13.801 |
ncl            | 210 |  97 |         3.610 |         1.000 |         3.611 |
igs            | 350 |  97 |         1.440 |         1.000 |         1.439 |
---------------|-----|-----|---------------|---------------|---------------|

5-2)      Solution Residuals weighted Average & STD:
====================================================

5-2-1)    With respect to the IGS05 stations:
=============================================

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod         85 |     1.4     -0.2     -0.1 |     2.8      3.0      9.8 |
esa         65 |     0.5      0.0     -0.2 |     3.5      3.1     11.4 |
emr         46 |     0.6      0.1      0.0 |     3.0      2.7     11.3 |
gfz         89 |     1.1      0.1     -0.1 |     2.7      2.7      9.7 |
jpl         65 |     1.9      0.2      0.4 |     2.9      3.4     10.7 |
MIT         95 |     1.5      0.1      0.3 |     2.6      2.9      9.5 |
ngs         95 |     0.9      0.1      0.2 |     2.6      2.7      8.5 |
sio         92 |     0.9      0.1     -0.1 |     2.9      2.6      8.4 |
grg         49 |     1.4      0.1      0.0 |     2.3      1.2      7.4 |
ncl         97 |     0.3      0.0      0.0 |     0.9      1.3      3.8 |
---------------|---------------------------|---------------------------|

5-2-2)    With respect to the Weekly Combination:
=================================================

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod        190 |     0.4      0.1     -0.9 |     1.1      1.2      3.4 |
esa        114 |    -0.6     -0.1     -1.1 |     1.7      1.8      4.2 |
emr         69 |    -0.7     -0.5      0.5 |     1.8      1.1      5.8 |
gfz        193 |     0.2      0.2     -0.6 |     0.8      1.0      2.9 |
jpl        120 |     0.9      0.3      0.3 |     1.7      2.3      6.5 |
MIT        232 |     0.3      0.0      0.2 |     0.7      0.8      2.3 |
ngs        214 |    -0.2     -0.1     -0.4 |     1.3      2.3      4.0 |
sio        237 |     0.0      0.1      0.3 |     1.2      1.2      3.5 |
grg         76 |     0.7     -0.2      1.9 |     2.2      3.2      7.6 |
ncl        200 |    -0.4      0.1      0.2 |     1.6      1.7      5.4 |
ITR         96 |    -1.0     -0.1     -0.2 |     2.4      2.4      8.7 |
---------------|---------------------------|---------------------------|

5-2-3)    With respect to the Cumulative Combination:
=====================================================

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod        176 |     0.9     -0.1     -1.2 |     1.6      1.6      6.3 |
esa        108 |     0.0     -0.1     -1.2 |     2.3      2.4      7.7 |
emr         69 |    -0.1     -0.6      0.4 |     2.1      2.0      7.4 |
gfz        182 |     0.7      0.1     -0.5 |     1.5      2.0      5.8 |
jpl        112 |     1.4      0.2      0.4 |     2.2      2.8      8.5 |
MIT        204 |     1.0      0.0      0.4 |     1.2      1.5      5.4 |
ngs        184 |     0.4     -0.2     -0.2 |     1.9      2.5      5.3 |
sio        202 |     0.5      0.0     -0.1 |     2.1      1.8      4.7 |
grg         76 |     1.2     -0.2      0.7 |     2.3      3.1      7.8 |
ncl        191 |     0.2      0.1      0.0 |     1.7      1.8      4.8 |
igs        257 |     0.5      0.0     -0.2 |     1.3      1.2      4.7 |
ITR        127 |    -0.3     -0.1     -0.1 |     2.2      2.1      8.0 |
---------------|---------------------------|---------------------------|

5-3)      7-Parameters Transformation: AC ----> IGS05.snx
=========================================================

5-3-1)    Estimates:
====================

Solution       |    R X      R Y      R Z      T X      T Y      T Z      SCL  |
               |   (mas)    (mas)    (mas)     (mm)     (mm)     (mm)    (ppb) |
---------------|---------------------------------------------------------------|
cod            |  -0.001   -0.021   -0.000      0.9      1.1      0.6    -0.35 |
esa            |   0.004   -0.054    0.074      6.8     -1.6      6.2    -0.49 |
emr            |   0.043   -0.018    0.037     -2.5      1.0     -1.3    -0.37 |
gfz            |   0.002   -0.043   -0.001      1.3      0.3      1.5    -0.56 |
jpl            |   0.010   -0.002   -0.023     -4.7      0.5     -8.2    -0.28 |
MIT            |   0.013   -0.000   -0.006      6.9     -1.9     11.1    -0.51 |
ngs            |   0.029   -0.075    0.001      6.6      1.7      5.2    -0.37 |
sio            |  -0.044    0.074    0.002     -6.4     -2.4     -9.3    -0.20 |
grg            |  -0.039   -0.028   -0.002      5.4      2.1      4.5    -0.32 |
ncl            |   0.008   -0.012   -0.005      2.0      0.0      0.8    -0.59 |
igs            |   0.000    0.000    0.000      0.0      0.0      0.0    -0.39 |
---------------|---------------------------------------------------------------|

5-3-2)    STD:
==============

Solution       |    R X      R Y      R Z      T X      T Y      T Z      SCL  |
               |   (mas)    (mas)    (mas)     (mm)     (mm)     (mm)    (ppb) |
---------------|---------------------------------------------------------------|
cod            |   0.044    0.046    0.047      1.2      1.2      1.1     0.18 |
esa            |   0.047    0.051    0.054      1.3      1.3      1.3     0.20 |
emr            |   0.055    0.060    0.067      1.5      1.5      1.5     0.24 |
gfz            |   0.043    0.044    0.046      1.1      1.1      1.1     0.17 |
jpl            |   0.050    0.054    0.052      1.3      1.3      1.3     0.21 |
MIT            |   0.042    0.044    0.045      1.1      1.1      1.1     0.17 |
ngs            |   0.041    0.043    0.046      1.1      1.1      1.1     0.17 |
sio            |   0.041    0.044    0.046      1.1      1.1      1.1     0.17 |
grg            |   0.056    0.058    0.069      1.5      1.5      1.5     0.24 |
ncl            |   0.041    0.043    0.045      1.1      1.1      1.1     0.17 |
igs            |   0.000    0.000    0.000      0.0      0.0      0.0     0.12 |
---------------|---------------------------------------------------------------|

5-4)      Geocenter:
====================

               |      X        Y        Z  |    s X      s Y      s Z  |
               |    (mm)     (mm)     (mm) |    (mm)     (mm)     (mm) |
---------------|---------------------------|---------------------------|
igs            |     4.5      0.6      3.2 |     1.0      0.6      2.3 |
---------------|---------------------------|---------------------------|

5-5)      ERP Residuals Weighted Average & STD:
===============================================

5-5-1)    Weighted Average:
===========================

Solution       |      UT       LOD       XPO      XPOR       YPO      YPOR  |
               |      us        us    .01mas    .01ma/d   .01mas    .01ma/d |
---------------|------------------------------------------------------------|
cod            |     ---        ---       ---       ---       ---       --- |
esa            |     ---        3.1      -1.1      -2.1      -1.7       7.9 |
emr            |     ---        4.8       5.7      15.5      -2.1      17.5 |
gfz            |     ---       14.7       0.1       6.4      -1.2       2.3 |
jpl            |     ---       -2.2      -0.6      23.7      -3.8       0.1 |
MIT            |     ---       -8.1      -2.1     -12.1       1.4     -17.0 |
ngs            |     ---       11.7       6.5      -0.9       0.8      14.2 |
sio            |     ---        8.8       0.5       ---      -0.8       --- |
grg            |     ---       -5.0       1.3       7.1       0.6       5.5 |
ncl            |     ---        4.9       0.6       ---       3.4       --- |
ITR            |     ---        ---       ---       ---       ---       --- |
BuA            |     ---        7.0       2.8       5.6       1.0       3.7 |
---------------|------------------------------------------------------------|

5-5-2)    STD:
==============

Solution       |      UT       LOD       XPO      XPOR       YPO      YPOR  |
               |      us        us    .01mas    .01ma/d   .01mas    .01ma/d |
---------------|------------------------------------------------------------|
cod            |     ---        ---       ---       ---       ---       --- |
esa            |     ---        4.7       1.4       5.4       0.9      12.5 |
emr            |     ---        2.9       2.8      10.1       1.9      14.4 |
gfz            |     ---        5.5       1.5       4.7       2.5       6.9 |
jpl            |     ---       15.4       1.1       8.4       1.9       8.5 |
MIT            |     ---        3.6       1.3       3.5       1.7       5.2 |
ngs            |     ---       11.5       6.7       7.5       5.7       6.1 |
sio            |     ---        2.6       1.3       ---       2.5       --- |
grg            |     ---       35.2       3.1       7.7       3.6      10.3 |
ncl            |     ---        2.1       3.3       ---       1.4       --- |
ITR            |     ---        ---       ---       ---       ---       --- |
BuA            |     ---       14.3       3.9      10.7       5.5       9.7 |
---------------|------------------------------------------------------------|

5-6)      Satellite Antenna Offset Residuals weighted Average & STD:
====================================================================
          No Satellite phase center ... 

5-7)      Outliers:
===================

Thresholds set at 5 sigmas and 50 mm.

 Solution             Solution           |  Station   |    N       E       U  |
              Minus                      |code id soln|   (mm)    (mm)    (mm)|
-----------------------------------------|------------|-----------------------|
                                         |            |                       |
ITRF_IGS05.snx       cod14897.snx        |CAS1  A    3|    3.1     1.4   -26.0|
ITRF_IGS05.snx       cod14897.snx        |OHI3  A    1|    3.8     3.8   -21.8|
                                         |            |                       |
ITRF_IGS05.snx       gfz14897.snx        |OHI2  A    1|    5.6     1.9   -37.9|
                                         |            |                       |
ITRF_IGS05.snx       MIT14897.snx        |CAS1  A    3|    0.4     3.3   -17.7|
ITRF_IGS05.snx       MIT14897.snx        |OHI2  A    1|    7.1     2.8   -30.9|
ITRF_IGS05.snx       MIT14897.snx        |TOW2  A    1|   -2.8    -0.1    22.6|
                                         |            |                       |
igs08P1488.snx       ncl1489g.snx        |HRAO  A    2|   11.2     8.7    -5.0|
                                         |            |                       |
IGS08P29.snx         ncl1489g.snx        |COCO  A    4|   10.0     2.0     3.1|
IGS08P29.snx         ncl1489g.snx        |PETP  A    4|   13.5    -5.0   -16.4|
                                         |            |                       |
IGS08P29.snx         igs08P1489.snx      |ALRT  A    1|    0.7     4.0    -1.1|
IGS08P29.snx         igs08P1489.snx      |KIT3  A    2|    2.0    -5.7     1.7|
IGS08P29.snx         igs08P1489.snx      |NISU  A    1|    8.7     3.3    -0.1|
IGS08P29.snx         igs08P1489.snx      |OUS2  A    2|    4.5    -5.5     8.9|
IGS08P29.snx         igs08P1489.snx      |TSKB  A    2|    2.8    -6.2     8.1|
-----------------------------------------|------------|-----------------------|