Subject: [IGSREPORT-8468] Wk 1122 IGS SINEX Combination
From: David Hutchison <[email-masked]>
To: [email-masked]
Date: Thu, 26 Jul 2001 14:57:24 EDT

******************************************************************************
IGS Electronic Report   26 Jul 11:57:27 PDT 2001      Message Number 8468
******************************************************************************

Author:  R. Ferland , D. Hutchison

===================================================================
 Combined AC  solution for GPS week 1122 -  01/07/08 to 01/07/14
===================================================================

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

igs01P1122.snx  Combined weekly solution. 
igs01P1122.erp  Daily Earth Rotation Parameters.
igs00p02.erp    Daily Earth Rotation Parameters since GPS week 1013.
IGS01P28.snx    Cumulative Combined solution. 
igs01P1122.sum  This file.
igs01P1122.itr  Residuals between the AC and the IGS97 for the RF stations. 
igs01P1122.res  Residuals between the AC and the Combined Weekly solution.
IGS01P28.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 with
     AREQ excluded.
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 50 ITRF station positions
     and velocities (AREQ excluded). 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 without AREQ 
           (renamed locally as ITRF_IGS00P04_RS50noAREQ.snx)
     igs = igs01P1122.snx
     IGS = IGS01P28.snx

     BuA = IERS Bulletin A

     emr gfz ngs sio 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
     IGS00P04_RS51.SNX realization of ITRF97. Starting with GPS week 1120,
     AREQ is excluded from the reference frame (ITR above).

     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            | 120 |  40 |        33.638 |         1.000 |        33.624 |
emr            |  45 |  27 |         3.086 |         1.021 |         3.150 |
esa            |  52 |  37 |        10.484 |         0.981 |        10.282 |
gfz            |  73 |  36 |        13.203 |         1.000 |        13.200 |
jpl            |  62 |  28 |         4.525 |         0.999 |         4.521 |
ngs            |  72 |  43 |        20.905 |         1.000 |        20.895 |
igs            | 121 |  45 |         1.290 |         1.014 |         1.308 |
---------------|-----|-----|---------------|---------------|---------------|

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         38 |     0.8      0.2      0.1 |     3.1      3.7     11.9 |
emr         25 |     1.1     -0.1     -0.4 |     3.5      5.6     10.8 |
esa         34 |    -0.4      0.0     -0.7 |     5.6      3.9     11.2 |
gfz         35 |     0.1     -0.2     -1.1 |     3.0      4.0     10.6 |
jpl         27 |     1.1      0.2     -0.7 |     3.1      4.9     11.2 |
ngs         42 |    -1.9      0.9      0.4 |     5.3      5.4     11.5 |
---------------|---------------------------|---------------------------|

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

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod        107 |     1.2      0.0      0.7 |     1.6      2.3      6.7 |
emr         40 |     0.0      0.4      0.6 |     2.2      4.2      4.4 |
esa         51 |    -0.6     -0.3      1.1 |     3.8      4.4      6.7 |
gfz         63 |    -0.5     -0.6      0.9 |     1.9      1.9      4.3 |
jpl         53 |     0.1      0.7      0.1 |     1.4      1.5      4.3 |
ngs         65 |    -1.8      0.0      1.1 |     3.8      4.2      8.0 |
ITR         44 |    -0.4     -0.2      0.0 |     3.2      4.1     10.6 |
---------------|---------------------------|---------------------------|

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

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod        108 |     1.1      0.9      0.2 |     3.3      3.9     11.7 |
emr         41 |     0.9      0.0     -1.3 |     2.8      6.0      8.8 |
esa         52 |    -0.4      0.6      0.8 |     5.4      4.8      8.0 |
gfz         63 |    -0.1     -0.1     -0.8 |     2.6      3.4      8.1 |
jpl         53 |     1.1      0.7     -1.5 |     2.4      3.3     10.0 |
ngs         67 |    -1.2      0.6     -0.4 |     5.0      5.4      9.6 |
igs        121 |     0.2      0.7     -0.9 |     2.6      2.7      8.0 |
ITR         50 |     0.0      0.0     -0.2 |     1.5      2.2      6.3 |
---------------|---------------------------|---------------------------|

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            |   0.099   -0.137    0.059     11.1      9.4     -9.4     2.74 |
emr            |  -0.017   -0.027   -0.024      1.3     10.4     11.2     2.07 |
esa            |   0.118    0.042   -0.014     -7.7      9.4      8.5     1.16 |
gfz            |  -0.022    0.007   -0.125     -2.4      0.8     -4.9     2.63 |
jpl            |  -0.061   -0.056   -0.066     -2.4      7.2    -35.8     2.43 |
ngs            |   0.111    0.164   -0.298      1.6      2.8     12.8     2.05 |
---------------|---------------------------------------------------------------|

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            |   0.065    0.065    0.073      1.7      1.7      1.7     0.26 |
emr            |   0.081    0.079    0.090      2.1      2.1      2.1     0.32 |
esa            |   0.071    0.071    0.078      1.8      1.8      1.8     0.28 |
gfz            |   0.066    0.066    0.077      1.7      1.7      1.7     0.27 |
jpl            |   0.076    0.074    0.086      2.0      1.9      1.9     0.30 |
ngs            |   0.060    0.061    0.069      1.6      1.6      1.6     0.25 |
---------------|---------------------------------------------------------------|

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

               |      X        Y        Z  |    s X      s Y      s Z  |
               |    (mm)     (mm)     (mm) |    (mm)     (mm)     (mm) |
---------------|---------------------------|---------------------------|
igs            |     2.6      7.9    -25.9 |     2.5      2.5      7.9 |
---------------|---------------------------|---------------------------|

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            |     ---       15.6       6.8       2.4      -8.9        .6 |
emr            |     ---       23.4       5.2       5.4       5.2     -23.6 |
esa            |     ---       30.7      -1.5       2.2     -26.5       2.8 |
gfz            |     ---        8.4       9.6       -.4      11.4       1.6 |
jpl            |     ---      -80.3       1.1       6.1       1.9      -9.0 |
ngs            |     ---       18.5     -30.7     -81.1      11.9     -95.2 |
ITR            |     ---        ---       ---       ---       ---       --- |
BuA            |     ---       12.7       5.4       3.4      36.2       2.0 |
---------------|------------------------------------------------------------|

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

Solution       |      UT       LOD       XPO      XPOR       YPO      YPOR  |
               |      us        us    .01mas    .01ma/d   .01mas    .01ma/d |
---------------|------------------------------------------------------------|
cod            |     ---       10.0       3.2       6.6       2.3       7.6 |
emr            |     ---       19.1       6.7      20.9       4.5      16.3 |
esa            |     ---       11.4       7.5      21.4       4.9      20.1 |
gfz            |     ---        9.6       4.1      16.1       1.7       6.5 |
jpl            |     ---       46.0       6.1      21.1       2.6      29.2 |
ngs            |     ---       22.1      11.7      59.2       3.8      49.0 |
ITR            |     ---        ---       ---       ---       ---       --- |
BuA            |     ---       13.9      10.2      19.4       8.6      15.0 |
---------------|------------------------------------------------------------|

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

Thresholds set at 5 sigmas and 50 mm.

 Solution             Solution           |  Station   |    N       E       U  |
              Minus                      |code id soln|   (mm)    (mm)    (mm)|
-----------------------------------------|------------|-----------------------|
                                         |            |                       |
ITRF_IGS00P04_RS50no ngs11227.snx        |GRAZ  A ----|   -6.2     7.7   -81.6|
                                         |            |                       |
cod11227.snx         esa11227.snx        |OHIG  A ----|    5.7    -0.2    58.9|
                                         |            |                       |
cod11227.snx         jpl11227.snx        |INEG  A ----|    4.2     3.1    50.6|
                                         |            |                       |
emr11227.snx         esa11227.snx        |SANT  A ----|   16.0    -1.5    51.8|
                                         |            |                       |
cod11227.snx         esa11227.snx        |RIOG  A ----|   11.3    -5.0    51.7|
                                         |            |                       |
igs01P1121.snx       cod11227.snx        |AREQ  A ----|   32.6    33.2    -5.8|
                                         |            |                       |
igs01P1121.snx       emr11227.snx        |AREQ  A ----|   31.1    26.7   -19.8|
                                         |            |                       |
igs01P1121.snx       gfz11227.snx        |AREQ  A ----|   26.8    27.6   -13.2|
                                         |            |                       |
igs01P1121.snx       jpl11227.snx        |AREQ  A ----|   30.2    30.5   -13.3|
                                         |            |                       |
IGS01P27.snx         gfz11227.snx        |COCO  A ----|    5.7   -28.8     2.5|
                                         |            |                       |
IGS01P27.snx         jpl11227.snx        |COCO  A ----|    5.8   -22.6    -1.5|
                                         |            |                       |
IGS01P27.snx         igs01P1122.snx      |AREQ  A ----|   33.0    28.0    -9.3|
IGS01P27.snx         igs01P1122.snx      |BAKO  A ----|    0.6     3.6   -51.2|
IGS01P27.snx         igs01P1122.snx      |COCO  A ----|    4.9   -26.2    -2.4|
-----------------------------------------|------------|-----------------------|

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

5-7-1) Station Name Conflicts:
============================= 

IERS DOMES NO    cod    emr    esa    gfz    jpl    ngs    IGS    igs
============= ====== ====== ====== ====== ====== ====== ====== ======
    42005M001 GALA A        GALA B GALA A GALA A GALA B GALA A GALA A
    40114M001 NRC1 A NRC1 A NRC1 A        NRC1 A        NRC1 A NRC1 A
                     NRC2 A                                          
    40405S031 GOLD A        GOL2 A GOLD A        GOL2 A GOLD A GOLD A
    50103M108 TIDB A TIDB A TID2 A TIDB A TIDB A TID2 A TIDB A TIDB A
    30314M002 SUTH A        SUTH B SUTH A SUTH A SUTH A SUTH A SUTH A
    42202M005 AREQ A AREQ A        AREQ A AREQ A AREQ B              
    22003M001               PIMO B        PIMO A        PIMO A PIMO A
    50107M004               YAR1 A YAR1 A YAR1 A YAR1 A YAR1 A YAR1 A
                                          YAR2 A                     

5-7-2) Station Antenna Conflicts:
================================ 

 _______________________ 
|Enforcing these aliases|
|_______________________|
   TIDB A: TID2 A  
   GOLD A: GOL2 A  
   PIMO A: PIMO B  
   GALA A: GALA B  
   SUTH A: SUTH B  
   YAR1 A: YAR2 A  

ABBREVIATIONS:
-------------
    L1: L1 Offset
    L2: L2 Offset
   ECC: Eccentricity
    -N: NORTH (Latitude) 
    -E: EAST  (Longitude)
    -U: UP    (Vertical) 

Compare to file IGS.SNX (IGS).                

Antenna Conflicts in file cod11227.snx (cod).           
------- --------- -- ---- 
    STN       L1-U   L1-N   L1-E   L2-U   L2-N   L2-E  ECC-U  ECC-N  ECC-E
AGY CODE PT   (M.)   (M.)   (M.)   (M.)   (M.)   (M.)   (M.)   (M.)   (M.)
=== ==== ==   ====   ====   ====   ====   ====   ====   ====   ====   ====
cod MDVO  A  .0780  .0000 -.0030  .0744 -.0031 -.0013  .1456  .0000  .0000
IGS MDVO  A  .0960 -.0016  .0009  .0944  .0016  .0041  .1456  .0000  .0000

Antenna Conflicts in file ngs11227.snx (ngs).           
------- --------- -- ---- 
    STN       L1-U   L1-N   L1-E   L2-U   L2-N   L2-E  ECC-U  ECC-N  ECC-E
AGY CODE PT   (M.)   (M.)   (M.)   (M.)   (M.)   (M.)   (M.)   (M.)   (M.)
=== ==== ==   ====   ====   ====   ====   ====   ====   ====   ====   ====
ngs BAKO  A  .0757  .0000  .0000  .0745  .0000  .0000 1.6160  .0000  .0000
IGS BAKO  A  .0780  .0000 -.0030  .0744 -.0031 -.0013 1.6160  .0000  .0000

ngs GRAZ  A  .0000  .0000  .0000  .0000  .0000  .0000 1.9640  .0000  .0000*
IGS GRAZ  A  .1100  .0000  .0000  .1280  .0000  .0000 1.9640  .0000  .0000
* Antenna listed as "NULL".

ngs WUHN  A  .1081  .0000  .0000  .1256  .0000  .0000 2.3200  .0000  .0000
IGS WUHN  A  .1100  .0000  .0000  .1280  .0000  .0000 2.3200  .0000  .0000

The following files have no antenna conflicts: 
   - emr11227.snx (emr)            
   - esa11227.snx (esa)            
   - gfz11227.snx (gfz)            
   - jpl11227.snx (jpl)            
--