Subject: [IGSREPORT-8572] Wk 1127 IGS SINEX Combination
From: Remi Ferland <[email-masked]>
To: [email-masked] (IGS Report Mailbox)
Date: Thu, 30 Aug 2001 19:40:41 EDT

******************************************************************************
IGS Electronic Report   30 Aug 16:40:45 PDT 2001      Message Number 8572
******************************************************************************

Author:  R. Ferland , D. Hutchison

===================================================================
 Combined AC  solution for GPS week 1127 -  01/08/12 to 01/08/18
===================================================================

1) Contacts:
============
e-mail: [email-masked]
Tel:    (613)995-4002 (Remi Ferland)
Fax:    (613)995-3215

2) Products:
============
All products are available at cddisa.gsfc.nasa.gov

igs01P1127.snx  Combined weekly solution. 
igs01P1127.erp  Daily Earth Rotation Parameters.
igs00p02.erp    Daily Earth Rotation Parameters since GPS week 1013.
IGS01P33.snx    Cumulative Combined solution. 
igs01P1127.sum  This file.
igs01P1127.itr  Residuals between the AC and the IGS97 for the RF stations. 
igs01P1127.res  Residuals between the AC and the Combined Weekly solution.
IGS01P33.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
     IGS97 stations at the current epoch.
     ftp://igscb.jpl.nasa.gov/igscb/station/coord/IGS00P04_RS51.SNX.Z
3-4) The AC are compared to IGS97, 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 IGS97 of the current
     epoch using a 7-parameters transformation. The singular cumulative
     combined solution is aligned to the IGS97 of the reference epoch
     using a 14-parameters transformation and the 51 ITRF station positions
     and velocities. The IGS97 is a realization of ITRF97.

     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 = IGS00P04_RS51.SNX
     igs = igs01P1127.snx
     IGS = IGS01P33.snx

     BuA = IERS Bulletin A

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

     Solutions with manual station deletion:
         From the original solution:
             ITR  AREQ
         After unconstraining:
             emr  NRC1  NRC2

     4-1) Starting with GPS week 1065, the solutions are aligned to the
     IGS00P04_RS51.SNX realization of ITRF97.

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

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            | 125 |  40 |        34.066 |         1.000 |        34.066 |
emr            |  49 |  31 |         3.887 |         1.000 |         3.887 |
esa            |  54 |  36 |        11.319 |         1.000 |        11.319 |
gfz            |  84 |  38 |        13.093 |         1.000 |        13.094 |
jpl            |  65 |  27 |         4.629 |         1.000 |         4.630 |
ngs            |  74 |  45 |        21.546 |         1.000 |        21.546 |
sio            | 139 |  41 |         1.917 |         1.000 |         1.917 |
mit            | 162 |  44 |         3.993 |         1.000 |         3.995 |
ncl            | 102 |  45 |         2.664 |         1.189 |         3.169 |
igs            | 153 |  46 |         1.502 |         0.999 |         1.500 |
---------------|-----|-----|---------------|---------------|---------------|

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

5-2-1)    With respect to the IGS97 stations:
=============================================

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod         39 |     0.1      0.9      0.0 |     3.9      4.7     12.1 |
emr         30 |    -1.2      0.0      0.0 |     4.1      5.4     14.2 |
esa         35 |    -0.3      0.6     -1.2 |     7.3      5.0     14.8 |
gfz         37 |    -0.4      0.6     -1.4 |     3.2      4.6     13.3 |
jpl         26 |    -0.2      0.4     -0.2 |     2.8      5.3     11.8 |
ngs         44 |    -2.3      1.0     -0.4 |     4.1      5.8     12.0 |
sio         40 |     0.2      0.6     -2.5 |     3.6      4.0     12.3 |
mit         43 |     0.3      0.7     -1.0 |     3.5      4.1     11.5 |
ncl         44 |    -0.2      0.3     -0.6 |     3.0      4.2     10.4 |
---------------|---------------------------|---------------------------|

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

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod        122 |     0.5     -0.2      0.6 |     1.7      1.9     10.7 |
emr         47 |    -1.9      0.7     -1.0 |     2.6      4.5      7.7 |
esa         53 |    -0.7      1.0     -1.3 |     4.9      4.3      8.5 |
gfz         79 |    -1.1      0.4     -1.0 |     1.5      1.7      6.3 |
jpl         62 |    -1.1      1.5     -1.1 |     1.8      2.2      7.1 |
ngs         72 |    -2.1     -0.1     -1.0 |     2.3      3.8      7.5 |
sio        135 |     0.0     -0.3      1.6 |     1.9      2.0      6.8 |
mit        147 |     0.3      0.2     -0.5 |     0.8      0.8      4.8 |
ncl         99 |    -0.4     -0.3      0.2 |     1.3      1.9      4.2 |
ITR         45 |    -0.1     -0.3     -0.4 |     3.3      4.5     12.0 |
---------------|---------------------------|---------------------------|

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

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod        123 |     0.3      1.1     -1.0 |     3.5      4.1     11.6 |
emr         48 |    -1.1      0.0     -1.1 |     3.6      6.9      9.9 |
esa         54 |    -0.4      1.4     -2.5 |     6.4      6.0     11.6 |
gfz         79 |    -1.3      0.7     -1.4 |     3.1      3.3     10.0 |
jpl         62 |    -0.6      1.6     -1.1 |     2.6      3.7      9.3 |
ngs         73 |    -2.0      0.4     -1.8 |     3.7      5.5      8.6 |
sio        136 |    -0.3      0.9      0.1 |     3.7      4.1      9.1 |
mit        147 |     0.1      1.5     -2.0 |     2.8      3.0      7.7 |
ncl        100 |    -0.5      0.1     -0.4 |     2.8      4.3      6.9 |
igs        153 |    -0.2      1.1     -1.3 |     2.6      3.0      6.7 |
ITR         50 |    -0.1      0.0     -0.2 |     1.7      2.4      6.8 |
---------------|---------------------------|---------------------------|

5-3)      7-Parameters Transformation: AC ----> IGS00P04_RS51.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            |   0.129   -0.108    0.055      5.3     13.6    -12.2     2.73 |
emr            |   0.016    0.048   -0.021      1.0    -14.1    -22.3     2.06 |
esa            |   0.040    0.007   -0.025    -16.0      1.6     -3.6     1.87 |
gfz            |  -0.007    0.004   -0.047     -2.3      1.3     -3.5     2.58 |
jpl            |  -0.009   -0.028   -0.045     -9.4      7.9    -30.5     2.19 |
ngs            |   0.216    0.263   -0.355     -5.2     24.3     42.2     2.91 |
sio            |   0.129    0.122   -0.081     -2.2      8.8     33.8     1.81 |
mit            |  -0.013    0.007   -0.021     -1.1     -0.8     -1.2     2.40 |
ncl            |  -0.072    0.578   -1.135     -0.4     -1.6    -16.5     1.98 |
---------------|---------------------------------------------------------------|

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            |   0.063    0.065    0.071      1.6      1.6      1.6     0.26 |
emr            |   0.072    0.071    0.080      1.9      1.9      1.9     0.29 |
esa            |   0.067    0.068    0.076      1.8      1.8      1.7     0.27 |
gfz            |   0.065    0.065    0.074      1.7      1.7      1.7     0.26 |
jpl            |   0.077    0.073    0.091      2.0      2.0      2.0     0.31 |
ngs            |   0.059    0.061    0.068      1.6      1.6      1.5     0.24 |
sio            |   0.062    0.063    0.071      1.6      1.6      1.6     0.25 |
mit            |   0.060    0.061    0.070      1.6      1.6      1.6     0.24 |
ncl            |   0.060    0.060    0.069      1.6      1.6      1.5     0.24 |
---------------|---------------------------------------------------------------|

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

               |      X        Y        Z  |    s X      s Y      s Z  |
               |    (mm)     (mm)     (mm) |    (mm)     (mm)     (mm) |
---------------|---------------------------|---------------------------|
igs            |    -5.5     10.9    -28.1 |     2.4      2.8      9.3 |
---------------|---------------------------|---------------------------|

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            |     ---       11.4      -9.9      -3.1      -3.8       1.4 |
emr            |     ---        6.6      14.1      13.0      12.8       5.9 |
esa            |     ---       19.7       5.8       1.0     -13.5      -1.8 |
gfz            |     ---       21.4      -1.3        .7       4.4      -4.5 |
jpl            |     ---        9.1       3.7       -.7       2.9      18.8 |
ngs            |     ---      -12.9     -26.5      59.2      -4.2    -153.0 |
sio            |     ---      -32.1      -4.5       7.0       5.0     -25.9 |
mit            |     ---       21.4        .4        .4        .8        .3 |
ncl            |     ---        ---       ---       ---       ---       --- |
ITR            |     ---        ---       ---       ---       ---       --- |
BuA            |     ---       11.4       6.7       1.0      27.9        .7 |
---------------|------------------------------------------------------------|

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

Solution       |      UT       LOD       XPO      XPOR       YPO      YPOR  |
               |      us        us    .01mas    .01ma/d   .01mas    .01ma/d |
---------------|------------------------------------------------------------|
cod            |     ---       13.7       6.6      20.2       5.6      12.5 |
emr            |     ---       10.8       5.7      20.1       7.4      19.6 |
esa            |     ---       11.0       4.3      14.6       8.2      24.9 |
gfz            |     ---       17.6       1.7      11.1       3.1       9.0 |
jpl            |     ---       11.7       1.7      21.4       4.3       5.7 |
ngs            |     ---       37.6       8.5      27.7      10.5      53.6 |
sio            |     ---       13.4       6.3      18.1       6.8      25.1 |
mit            |     ---        3.3        .6       1.3        .7       1.7 |
ncl            |     ---        ---       ---       ---       ---       --- |
ITR            |     ---        ---       ---       ---       ---       --- |
BuA            |     ---        5.8       5.6      16.8       4.9      17.2 |
---------------|------------------------------------------------------------|

5-6)      Outliers:
===================

Thresholds set at 5 sigmas and 50 mm.

 Solution             Solution           |  Station   |    N       E       U  |
              Minus                      |code id soln|   (mm)    (mm)    (mm)|
-----------------------------------------|------------|-----------------------|
                                         |            |                       |
IGS00P04_RS51.snx    sio11277.snx        |HOB2  A ----|    7.3    -2.6   -52.9|
IGS00P04_RS51.snx    sio11277.snx        |TSKB  A ----|   -4.2   -10.9    35.9|
                                         |            |                       |
jpl11277.snx         sio11277.snx        |NVSK  A ----|   -1.2    -0.7    98.6|
                                         |            |                       |
jpl11277.snx         mit1127g.snx        |NVSK  A ----|   -0.2     0.1    53.4|
                                         |            |                       |
ngs11277.snx         sio11277.snx        |BAKO  A ----|   16.5    -4.8    50.4|
                                         |            |                       |
ngs11277.snx         mit1127g.snx        |BAKO  A ----|   12.3    -6.4    60.5|
                                         |            |                       |
IGS01P32.snx         gfz11277.snx        |COCO  A ----|    7.6   -26.5     3.3|
                                         |            |                       |
IGS01P32.snx         mit1127g.snx        |COCO  A ----|    8.6   -24.9     0.5|
                                         |            |                       |
IGS01P32.snx         igs01P1127.snx      |COCO  A ----|    7.2   -24.5    -2.7|
-----------------------------------------|------------|-----------------------|

5-7)      Conflicts:
====================

IERS DOMES NO    cod    emr    esa    gfz    jpl    ngs    sio    IGS    igs
============= ====== ====== ====== ====== ====== ====== ====== ====== ======
    50107M004 YAR1 A        YAR1 A YAR1 A YAR1 A YAR1 A YAR1 A YAR1 A YAR1 A
                                          YAR2 A
    22306M002 IISC A IISC A IISC B IISC A IISC A IISC B IISC A IISC A IISC A
    13407S012 MADR A               MADR A MAD2 A MADR A MAD2 A MADR A MADR A
    40114M001 NRC1 A NRC1 A NRC1 A        NRC1 A        NRC1 A NRC1 A NRC1 A
                     NRC2 A 
    40405S031 GOLD A               GOLD A        GOL2 A GOL2 A GOLD A GOLD A
    42005M001 GALA A        GALA B GALA A GALA A GALA B GALA A GALA A GALA A
    42202M005 AREQ A AREQ A        AREQ A AREQ A AREQ B AREQ A AREQ A AREQ A
    50103M108 TIDB A TIDB A TID2 A TIDB A TIDB A TID2 A TID2 A TIDB A TIDB A
    22003M001               PIMO B PIMO A PIMO A        PIMO A PIMO A PIMO A
 
MISSING IERS DOMES NOS AT gfz:
-----------------------------
  BISH A
 
MISSING IERS DOMES NOS AT IGS:
-----------------------------
  ELAT A
IERS DOMES NO    mit    ncl    IGS    igs
============= ====== ====== ====== ======
    13407S012 MADR A MADR A MADR A MADR A
              MAD2 A 
    31303M001 MAS1 A 
    31303M002        MAS1 A MAS1 A MAS1 A
    40114M001 NRC1 A NRC1 A NRC1 A NRC1 A
              NRC2 A 
    40405S031 GOLD A        GOLD A GOLD A
              GOL2 A 
    50103M108 TIDB A TID2 A TIDB A TIDB A
              TID2 A TIDB A
    50107M004 YAR1 A YAR1 A YAR1 A YAR1 A
              YAR2 A 
    12309M001 MDVO A 
    12309M002               MDVO A MDVO A
 
MISSING IERS DOMES NOS AT mit:
-----------------------------
  BISH A
 
MISSING IERS DOMES NOS AT IGS:
-----------------------------
  ELAT A
--