Subject: [IGSREPORT-8446] Wk 1121 IGS SINEX Combination *RESUBMISSION*
From: David Hutchison <[email-masked]>
To: [email-masked]
Date: Thu, 19 Jul 2001 23:29:32 EDT

******************************************************************************
IGS Electronic Report   19 Jul 20:29:34 PDT 2001      Message Number 8446
******************************************************************************

Author:  R. Ferland , D. Hutchison

===================================================================
 Combined AC  solution for GPS week 1121 -  01/07/01 to 01/07/07
===================================================================

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

igs01P1121.snx  Combined weekly solution. 
igs01P1121.erp  Daily Earth Rotation Parameters.
igs00p02.erp    Daily Earth Rotation Parameters since GPS week 1013.
IGS01P27.snx    Cumulative Combined solution. 
igs01P1121.sum  This file.
igs01P1121.itr  Residuals between the AC and the IGS97 for the RF stations. 
igs01P1121.res  Residuals between the AC and the Combined Weekly solution.
IGS01P27.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 removed.
3-4) The AC are compared to IGS97 (AREQ removed), to each other, to the previous 
     week's 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 removed). 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 = igs01P1121.snx
     IGS = IGS01P27.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.

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

     4-3) Though the earthquake near AREQ caused roughly 0.5 m. change
     in position from week 1119 to 1120, little position difference
     was seen at AREQ (weekly solution) between weeks 1120 and 1121.

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            | 123 |  39 |        33.389 |         1.000 |        33.389 |
emr            |  44 |  25 |         3.086 |         1.000 |         3.086 |
esa            |  53 |  34 |        12.431 |         1.000 |        12.431 |
gfz            |  72 |  35 |        15.911 |         0.998 |        15.882 |
jpl            |  63 |  27 |         5.378 |         1.001 |         5.383 |
ngs            |  68 |  41 |        25.100 |         0.993 |        24.932 |
sio            | 132 |  39 |         2.212 |         1.001 |         2.214 |
igs            | 121 |  43 |         1.159 |         1.001 |         1.160 |
---------------|-----|-----|---------------|---------------|---------------|

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 |     1.0      0.1      0.5 |     3.3      3.8     12.6 |
emr         24 |     2.5     -0.1      0.3 |     4.5      5.4      8.7 |
esa         33 |     1.3     -0.3     -1.4 |     7.1      6.6     12.7 |
gfz         34 |     0.1      0.2     -1.2 |     3.4      4.7     10.8 |
jpl         26 |     0.6      0.2      0.0 |     3.3      5.3     11.5 |
ngs         40 |    -1.9      0.5     -0.1 |     6.1      7.8     13.0 |
sio         38 |     0.0      0.4     -2.1 |     4.1      4.8     13.4 |
---------------|---------------------------|---------------------------|

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

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod        108 |     1.1     -0.3      2.2 |     2.0      1.8     10.3 |
emr         38 |     1.3      0.1     -0.3 |     3.2      3.3      9.5 |
esa         49 |     0.6     -1.0     -0.4 |     5.9      5.2      7.0 |
gfz         60 |    -0.6     -0.7      0.0 |     1.9      2.0      6.5 |
jpl         51 |    -0.5      0.7      0.2 |     1.8      1.6      7.6 |
ngs         61 |    -2.5     -0.5      0.1 |     5.0      6.8      7.4 |
sio        107 |    -0.4     -0.2      0.7 |     2.5      2.1      9.2 |
ITR         42 |    -0.2     -0.1     -0.1 |     2.9      4.0     10.3 |
---------------|---------------------------|---------------------------|

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

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod        110 |     1.0      1.0      1.1 |     3.2      3.6     12.0 |
emr         39 |     2.1      0.0     -0.6 |     3.6      4.6     11.0 |
esa         51 |     0.6      0.1     -0.9 |     6.9      6.3      9.9 |
gfz         62 |    -0.1      0.0     -1.8 |     3.1      3.8      8.8 |
jpl         53 |     0.8      0.3      0.0 |     2.9      4.6     10.5 |
ngs         64 |    -2.2      0.3     -1.2 |     5.4      7.5      9.6 |
sio        110 |    -0.3      0.8     -0.4 |     3.6      4.4      9.5 |
igs        121 |     0.0      0.8     -1.0 |     2.2      2.7      5.7 |
ITR         50 |     0.0      0.0     -0.2 |     1.5      2.2      6.2 |
---------------|---------------------------|---------------------------|

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            |   0.107   -0.112    0.076     10.5     10.7    -13.1     2.84 |
emr            |  -0.042   -0.084   -0.006     -1.0     -0.7    -40.1     2.57 |
esa            |   0.115    0.046   -0.060     -8.2     12.4     15.8     1.91 |
gfz            |  -0.001   -0.009   -0.013     -1.9      0.7     -4.4     2.80 |
jpl            |  -0.055   -0.032   -0.078      1.9      4.4    -39.0     2.12 |
ngs            |   0.155    0.304   -0.332     -7.4      5.7     47.9     3.00 |
sio            |   0.151   -0.082   -0.045      5.0      7.0     17.1     1.76 |
---------------|---------------------------------------------------------------|

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            |   0.064    0.064    0.073      1.7      1.7      1.6     0.26 |
emr            |   0.081    0.077    0.090      2.1      2.1      2.1     0.32 |
esa            |   0.071    0.068    0.079      1.8      1.8      1.8     0.28 |
gfz            |   0.068    0.067    0.078      1.8      1.8      1.8     0.27 |
jpl            |   0.077    0.076    0.085      2.0      2.0      2.0     0.31 |
ngs            |   0.062    0.062    0.071      1.6      1.6      1.6     0.25 |
sio            |   0.065    0.063    0.072      1.7      1.7      1.6     0.26 |
---------------|---------------------------------------------------------------|

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

               |      X        Y        Z  |    s X      s Y      s Z  |
               |    (mm)     (mm)     (mm) |    (mm)     (mm)     (mm) |
---------------|---------------------------|---------------------------|
igs            |     5.4      9.9    -25.1 |     2.4      2.0      7.6 |
---------------|---------------------------|---------------------------|

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            |     ---        6.9       4.9       1.3      -9.9       -.6 |
emr            |     ---       -9.5      -8.0      -1.9      -7.2      -4.2 |
esa            |     ---       12.9       4.5      -3.8     -36.3       -.8 |
gfz            |     ---        1.3       6.1      -1.3      14.1      -1.5 |
jpl            |     ---       -6.3       3.8      12.5       -.7       3.1 |
ngs            |     ---       -3.1     -13.1     -22.5     -44.3    -106.3 |
sio            |     ---       -5.5      -3.0      -1.7       3.8     -12.2 |
ITR            |     ---        ---       ---       ---       ---       --- |
BuA            |     ---       -8.6      10.1       2.0      26.3       -.6 |
---------------|------------------------------------------------------------|

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

Solution       |      UT       LOD       XPO      XPOR       YPO      YPOR  |
               |      us        us    .01mas    .01ma/d   .01mas    .01ma/d |
---------------|------------------------------------------------------------|
cod            |     ---       11.6       4.0      17.6       4.1       8.7 |
emr            |     ---       10.2       6.5      23.5       5.4      20.4 |
esa            |     ---       11.6       8.9      20.5       2.3       5.4 |
gfz            |     ---        9.2       2.6      10.2       2.6       8.5 |
jpl            |     ---       15.0       3.9      12.6       5.1       9.2 |
ngs            |     ---       34.4      12.6      67.5      18.8      62.8 |
sio            |     ---        5.4       3.7      14.1       3.5      13.4 |
ITR            |     ---        ---       ---       ---       ---       --- |
BuA            |     ---       12.2       9.0      18.7       8.0      13.9 |
---------------|------------------------------------------------------------|

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_RS51_n emr11217.snx        |IRKT  A ----|   -1.6    -2.1   -42.5|
                                         |            |                       |
ITRF_IGS00P04_RS51_n ngs11217.snx        |GRAZ  A ----|   -8.5     4.7   -83.0|
                                         |            |                       |
emr11217.snx         sio11217.snx        |CORD  A ----|   -5.0   -11.5    52.2|
                                         |            |                       |
esa11217.snx         jpl11217.snx        |SEY1  A ----|    9.6    36.3    65.9|
                                         |            |                       |
jpl11217.snx         ngs11217.snx        |SEY1  A ----|  -11.9     0.6   -53.5|
                                         |            |                       |
ngs11217.snx         sio11217.snx        |BAKO  A ----|   17.7   -15.0    52.3|
                                         |            |                       |
IGS01P26.snx         gfz11217.snx        |COCO  A ----|    8.6   -28.8    -5.0|
                                         |            |                       |
IGS01P26.snx         igs01P1121.snx      |COCO  A ----|    4.6   -28.0     4.7|
                                         |            |                       |
IGS01P27.snx         igs01P1121.snx      |NTUS  A ----|    7.1     3.3     2.4|
IGS01P27.snx         igs01P1121.snx      |ZWEN  A ----|   10.3    13.2   -10.1|
-----------------------------------------|------------|-----------------------|

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

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

IERS DOMES NO    cod    emr    esa    gfz    jpl    ngs    sio    IGS    igs
============= ====== ====== ====== ====== ====== ====== ====== ====== ======
    42005M001 GALA A        GALA B GALA A GALA A GALA B GALA A GALA A GALA A
    13407S012 MADR A               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                                                 
    40405S031 GOLD A        GOL2 A GOLD A        GOL2 A GOL2 A GOLD A GOLD A
    50103M108 TIDB A TIDB A TID2 A TIDB A TIDB A TID2 A TID2 A TIDB A TIDB A
    30314M002 SUTH A SUTH A SUTH B SUTH A SUTH A SUTH A SUTH A SUTH A SUTH A
    22003M001               PIMO B        PIMO A        PIMO A PIMO A PIMO A
    42202M005                      AREQ A AREQ A AREQ B AREQ A AREQ A AREQ A
    50107M004                             YAR2 A               YAR1 A YAR1 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  
   AREQ A: AREQ B  
   MADR A: MAD2 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 cod11217.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 ngs11217.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 at GRAZ 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: 
   - emr11217.snx (emr)            
   - esa11217.snx (esa)            
   - gfz11217.snx (gfz)            
   - jpl11217.snx (jpl)            
   - sio11217.snx (jpl)            
--