Subject: [IGSREPORT-8882] Wk 1143 IGS SINEX Combination
From: Remi Ferland <[email-masked]>
To: [email-masked] (IGS Report Mailbox)
Date: Thu, 20 Dec 2001 14:24:26 EST

******************************************************************************
IGS Electronic Report   20 Dec 11:24:29 PST 2001      Message Number 8882
******************************************************************************

Author:  R. Ferland, D. Hutchison

===================================================================
 Combined AC  solution for GPS week 1143 -  01/12/02 to 01/12/08
===================================================================

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

igs01P1143.snx  Combined weekly solution. 
igs01P1143.erp  Daily Earth Rotation Parameters.
igs00p02.erp    Daily Earth Rotation Parameters since GPS week 1013.
IGS01P49.snx    Cumulative Combined solution. 
igs01P1143.sum  This file.
igs01P1143.itr  Residuals between the AC and the IGS00 for the RF stations. 
igs01P1143.res  Residuals between the AC and the Combined Weekly solution.
IGS01P49.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
     IGS00 stations at the current epoch.
     ftp://igscb.jpl.nasa.gov/igscb/station/coord/IGS01P37_RS54.SNX.Z
3-4) The AC are compared to IGS00, 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 IGS00 of the current
     epoch using a 7-parameters transformation. The singular cumulative
     combined solution is aligned to the IGS00 of the reference epoch
     using a 14-parameters transformation and the 51 ITRF station positions
     and velocities. The IGS00 is a realization of ITRF2000.

     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 = IGS01P37_RS54.SNX
     igs = igs01P1143.snx
     IGS = IGS01P49.snx

     BuA = IERS Bulletin A

     mit is  used to quality control the weekly combination.
     gfz excluded from the geocenter estimation (Sec. 5-4).

     Solutions with manual station deletion:
         After unconstraining:
             emr  NRC1  NRC2

     4-1) Starting with GPS week 1065, the solutions are aligned to the
     IGS01P37_RS54.SNX realization of ITRF2000.

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

     4-3) Starting with this week combination and as already announced by
     Robert, the AC Coordinator, the weekly and the cumulative solutions
     are aligned to the "IGS realization of ITRF2000". Note that the
     transformation parameters betwen the IGS realization of ITRF97 and
     ITRF2000 can be found in the table below:
     
     Transformation from IGS(ITRF97) to IGS(ITRF2000) at epoch 01-JAN-1998:
     ====================================================================
              TX     TY     TZ    RX      RY      RZ       D
              mm     mm     mm    mas     mas     mas     ppb
     Offset  -6.0   -5.6   20.1 -0.040   0.001  -0.043  -1.403
     +/-      2.5    3.3    5.1   .053    .060    .036    .12
     --------------------------------------------------------------------
             dTX    dTY    dTZ    dRX     dRY     dRZ     dD
             mm/y   mm/y   mm/y   mas/y   mas/y   mas/y   ppb/y
     Drift    0.4    0.8    1.5  0.004  -0.001  -0.030  -0.012
     +/-      1.7    1.9    2.8   .038    .040    .034    .12
     --------------------------------------------------------------------
     * The IERS convention for the transformation parameters was followed.
     
     The accumulated erp file "igs00p02.erp" was also aligned to the
     "IGS realization of ITRF2000". Thanks also to Jan  for volunteering
     to check the updated file.

     Season's greetings.

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            | 124 |  46 |        28.538 |         1.000 |        28.527 |
emr            |  40 |  28 |         3.709 |         1.000 |         3.709 |
esa            |  53 |  33 |        14.825 |         1.000 |        14.825 |
gfz            |  80 |  39 |         6.547 |         0.999 |         6.542 |
jpl            |  67 |  28 |         5.111 |         1.000 |         5.110 |
sio            | 130 |  48 |         2.213 |         1.000 |         2.213 |
mit            | 157 |  48 |         3.692 |         0.886 |         3.270 |
igs            | 148 |  51 |         1.335 |         1.006 |         1.343 |
---------------|-----|-----|---------------|---------------|---------------|

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

5-2-1)    With respect to the IGS00 stations:
=============================================

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod         45 |     0.5      0.5     -1.0 |     3.3      3.8     12.0 |
emr         27 |    -5.1      0.3     -1.1 |     5.7      4.3      8.1 |
esa         30 |   -10.8      0.6      0.9 |     7.0      8.1     20.5 |
gfz         38 |    -0.6      0.0      0.5 |     2.5      3.3      7.4 |
jpl         27 |    -1.8     -0.6      0.6 |     2.6      3.4      7.9 |
sio         47 |    -0.2      0.1      0.4 |     2.5      3.3      9.5 |
mit         47 |     0.5      0.0     -0.5 |     2.5      2.7      7.1 |
---------------|---------------------------|---------------------------|

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

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod        121 |     1.1      1.2     -0.8 |     2.2      3.3     10.0 |
emr         39 |    -4.3      1.0     -0.6 |     3.8      4.3      6.3 |
esa         52 |   -10.6      1.6      3.7 |     5.9      6.9     16.4 |
gfz         74 |     0.4      0.7      2.0 |     1.3      1.6      5.6 |
jpl         62 |    -0.5     -1.0      2.0 |     1.7      1.8      7.7 |
sio        124 |     1.1     -0.3      2.6 |     1.3      2.5      6.9 |
mit        139 |     1.3      0.0      0.1 |     0.9      1.0      4.4 |
ITR         50 |     0.9      0.0      0.2 |     2.6      2.7      8.6 |
---------------|---------------------------|---------------------------|

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

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod        122 |    -0.2      0.8     -1.7 |     3.3      4.1     12.2 |
emr         40 |    -5.8      0.9      0.4 |     5.9      5.1      8.4 |
esa         53 |   -11.5      0.4      2.8 |     7.0      8.6     20.4 |
gfz         75 |    -1.0      0.2      2.2 |     3.1      3.4      7.8 |
jpl         63 |    -2.0     -1.0      1.6 |     3.5      3.4      9.0 |
sio        125 |    -0.4     -0.3      1.8 |     2.7      3.9     10.4 |
mit        140 |     0.0     -0.1     -0.6 |     2.7      3.1      8.1 |
igs        148 |    -1.5     -0.1     -0.6 |     2.5      2.7      7.4 |
ITR         54 |    -0.2     -0.1      0.0 |     0.3      0.4      0.9 |
---------------|---------------------------|---------------------------|

5-3)      7-Parameters Transformation: AC ----> IGS01P37_RS54.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            |   0.017   -0.023   -0.009     14.9     12.4     -0.0     1.70 |
emr            |   0.004    0.024   -0.062      0.3      8.0     17.6     0.80 |
esa            |   0.027    0.094   -0.011     -7.8     22.0      2.4     1.30 |
gfz            |  -0.035    0.008   -0.063     -0.7      0.2     -1.7     1.35 |
jpl            |  -0.004    0.002    0.012     -2.1     17.2     -8.9     0.61 |
sio            |   0.133   -0.112    0.001     11.8      7.6     95.2     1.49 |
mit            |  -0.012   -0.022   -0.134     -4.2     -2.5     25.5     1.26 |
---------------|---------------------------------------------------------------|

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            |   0.058    0.058    0.066      1.5      1.5      1.5     0.24 |
emr            |   0.076    0.073    0.093      2.0      2.0      2.0     0.31 |
esa            |   0.073    0.079    0.084      2.0      2.0      2.0     0.31 |
gfz            |   0.063    0.063    0.073      1.6      1.6      1.6     0.26 |
jpl            |   0.076    0.073    0.085      2.0      2.0      2.0     0.31 |
sio            |   0.057    0.057    0.065      1.5      1.5      1.5     0.23 |
mit            |   0.057    0.057    0.066      1.5      1.5      1.5     0.23 |
---------------|---------------------------------------------------------------|

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

               |      X        Y        Z  |    s X      s Y      s Z  |
               |    (mm)     (mm)     (mm) |    (mm)     (mm)     (mm) |
---------------|---------------------------|---------------------------|
igs            |     5.4      8.7     11.0 |     5.1      5.3      8.1 |
---------------|---------------------------|---------------------------|

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            |     ---       20.8      -3.3       ---       2.6       --- |
emr            |     ---        1.0        .5      12.9      15.3     -42.6 |
esa            |     ---       12.0     -27.7        .2      -7.1       1.6 |
gfz            |     ---      -14.2       2.3      -1.7       -.4      -3.6 |
jpl            |     ---       -1.4      -2.3     -19.4       6.6       4.9 |
sio            |     ---        -.7       7.0       3.6      -3.3       4.9 |
mit            |     ---        -.3       -.4        .8       2.7        .1 |
ITR            |     ---        ---       ---       ---       ---       --- |
BuA            |     ---        4.4      -2.4      -2.2      24.6      -3.6 |
---------------|------------------------------------------------------------|

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

Solution       |      UT       LOD       XPO      XPOR       YPO      YPOR  |
               |      us        us    .01mas    .01ma/d   .01mas    .01ma/d |
---------------|------------------------------------------------------------|
cod            |     ---       15.9       3.8       ---       2.9       --- |
emr            |     ---       10.6       5.5      22.9       5.5      41.1 |
esa            |     ---       12.3       3.4      10.7       8.4      10.6 |
gfz            |     ---       15.1       2.1       9.2       4.2      12.8 |
jpl            |     ---       43.2       3.5      15.6        .7      23.7 |
sio            |     ---       15.5       2.3       5.7       2.0      10.7 |
mit            |     ---        5.4       1.3       1.2        .9       2.1 |
ITR            |     ---        ---       ---       ---       ---       --- |
BuA            |     ---       13.7       5.3      11.1      12.4      17.5 |
---------------|------------------------------------------------------------|

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

Thresholds set at 5 sigmas and 50 mm.

 Solution             Solution           |  Station   |    N       E       U  |
              Minus                      |code id soln|   (mm)    (mm)    (mm)|
-----------------------------------------|------------|-----------------------|
                                         |            |                       |
cod11437.snx         esa11437.snx        |CRO1  A ----|  -14.9     0.0   -77.1|
cod11437.snx         esa11437.snx        |IISC  A ----|  -11.1     4.8   -81.9|
cod11437.snx         esa11437.snx        |MCM4  A ----|    1.3    -4.6   -51.7|
cod11437.snx         esa11437.snx        |SUTH  A ----|   -3.2     1.4    62.2|
                                         |            |                       |
emr11437.snx         esa11437.snx        |IISC  A ----|   -2.1   -15.0   -98.3|
                                         |            |                       |
esa11437.snx         gfz11437.snx        |IISC  A ----|    6.6     3.2    83.5|
esa11437.snx         gfz11437.snx        |SANT  A ----|    1.0    -1.6   -50.7|
                                         |            |                       |
esa11437.snx         jpl11437.snx        |CRO1  A ----|   13.8    -6.1    81.6|
esa11437.snx         jpl11437.snx        |IISC  A ----|    6.5     7.7    91.6|
esa11437.snx         jpl11437.snx        |KELY  A ----|   -2.0     3.1   -84.1|
                                         |            |                       |
esa11437.snx         sio11437.snx        |IISC  A ----|    8.6     1.4    85.8|
                                         |            |                       |
esa11437.snx         mit1143g.snx        |IISC  A ----|    9.9     2.5    87.7|
                                         |            |                       |
esa11437.snx         sio11437.snx        |ZIMM  A ----|   14.8    -9.1    62.0|
                                         |            |                       |
esa11437.snx         mit1143g.snx        |ZIMM  A ----|   14.3    -8.5    50.6|
                                         |            |                       |
IGS01P48.snx         cod11437.snx        |HOFN  A ----|    6.1    -3.0   -58.7|
                                         |            |                       |
IGS01P48.snx         gfz11437.snx        |HOFN  A ----|    8.7    -4.7   -47.4|
                                         |            |                       |
IGS01P48.snx         sio11437.snx        |ARTU  A ----|   -1.6     4.9    30.4|
IGS01P48.snx         sio11437.snx        |HOFN  A ----|    6.4    -3.5   -47.9|
IGS01P48.snx         sio11437.snx        |WHIT  A ----|    6.7    -2.8   -31.0|
                                         |            |                       |
IGS01P48.snx         mit1143g.snx        |HOFN  A ----|    6.9    -5.0   -54.5|
                                         |            |                       |
IGS01P48.snx         igs01P1143.snx      |COCO  A ----|    5.5   -16.1    -1.6|
-----------------------------------------|------------|-----------------------|

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

IERS DOMES NO    cod    emr    esa    gfz    jpl    sio    IGS    igs
============= ====== ====== ====== ====== ====== ====== ====== ======
    40405S031 GOLD A               GOLD A        GOL2 A GOLD A GOLD A
                                                 GOLD A
    13407S012 MADR 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
    42005M001 GALA A GALA A GALA B GALA A GALA A GALA A GALA A GALA A
    50103M108 TIDB A               TIDB A TID1 A TIDB A TIDB A TIDB A
                                          TIDB A 
    50107M004 YAR1 A YAR1 A YAR1 A YAR1 A YAR1 A YAR1 A YAR1 A YAR1 A
                                          YAR2 A 
    30314M002 SUTH A SUTH A SUTH B               SUTH A SUTH A SUTH A
    22306M002 IISC A IISC A IISC B IISC A IISC A IISC A IISC A IISC A
 
MISSING IERS DOMES NOS AT gfz:
-----------------------------
  BISH A
 
MISSING IERS DOMES NOS AT sio:
-----------------------------
  CAVA A  SFEL A  VOLT A
 
IERS DOMES NO    mit    IGS    igs
============= ====== ====== ======
    13407S012 MADR A MADR A MADR A
              MAD2 A
    31303M001 MAS1 A
    31303M002        MAS1 A MAS1 A
    40114M001 NRC1 A NRC1 A NRC1 A
              NRC2 A
    40405S031 GOLD A GOLD A GOLD A
              GOL2 A
    50103M108 TIDB A TIDB A TIDB A
              TID1 A
    50107M004 YAR1 A YAR1 A YAR1 A
              YAR2 A
    12309M001 MDVO A
    12309M002        MDVO A MDVO A
 
MISSING IERS DOMES NOS AT mit:
-----------------------------
  BISH A
--