Subject: [IGSREPORT-6497] Wk 1023 Preliminary IGS SINEX Combination
From: R. Ferland , D. Hutchison
Date: Wed, 29 Sep 1999 13:18:21 PDT

******************************************************************************
IGS Electronic Report    Wed Sep 29 13:18:21 PDT 1999      Message Number 6497
******************************************************************************

Author: R. Ferland , D. Hutchison
Subject: Wk 1023 Preliminary IGS SINEX Combination

===================================================================
 Combined AC  solution for GPS week 1023 -  99/08/15 to 99/08/21
===================================================================

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

igs99P1023.snx  Combined weekly solution. 
igs99P1023.erp  Daily Earth Rotation Parameters.
IGS99P33.snx    Cumulative Combined solution. 
igs99P1023.sum  This file.
igs99P1023.itr  Residuals between the AC and the ITRF97 for the RF stations.
igs99P1023.res  Residuals between the AC and the Combined Weekly solution.
IGS99P33.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
     ITRF97 Reference Frame (RF) stations at the current epoch.
     ftp://igscb.jpl.nasa.gov/igscb/station/coord/ITRF97_IGS_RS51.SNX.Z
3-4) The AC are compared to ITRF, 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 ITRF97 of the current
     epoch using a 7-parameters transformation. The singular cumulative
     combined solution is aligned to the ITRF97 of the reference epoch
     using a 14-parameters transformation and the 51 ITRF station positions
     and velocities.

     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:
===========

     igs = igs99P1023.snx
     IGS = IGS99P33.snx

     JPL = jpl1023g.snx
     jpl = jpl10237.snx

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

     Starting with week 1021 the solutions are aligned to ITRF97.
     A combined weekly and cumulative solutions were also aligned to
ITEF96 using 47 stations.  The transformation parameters were determined
between the ITRF96 and ITRF97 aligned solutions. All the common stations
were used without the covarinace information. The results were compared
to the official IGS(ITRF96) to IGS(ITRF97) transformations (See: ITRF96/97
IGS product changes, Message 2432).

igs99P1023.snx(ITRF96) to igs99P1023.snx(ITRF97) (epoch 1999/08/18) :
---------------------------------------------------------------------
Parameter   Estimated  Official    Difference
Rx (mas)      0.161      0.160       0.001
Ry (mas)     -0.241     -0.264       0.023
Rz (mas)     -0.056     -0.060       0.004
Tx (m)        0.0001     0.0003     -0.0002
Ty (m)        0.0010     0.0005      0.0005
Tz (m)       -0.0141    -0.0148      0.0007
Scl (ppb)     1.18       1.44       -0.26

IGS99P33.snx(ITRF96) to IGS99P33.snx(ITRF97) (epoch 1998/01/01) :
-------------------------------------------------------------------
Parameter   Estimated  Official    Difference
Rx (mas)      0.130      0.138      -0.008
Ry (mas)     -0.243     -0.239      -0.003
Rz (mas)     -0.055     -0.065       0.009
Tx (m)        0.0012     0.0014     -0.0002
Ty (m)        0.0002     0.0003     -0.0002
Tz (m)       -0.0119    -0.0117     -0.0002
Scl (ppb)     1.06       1.13       -0.07
dRx (mas/y)   0.006      0.013      -0.007
dRy (mas/y)  -0.016     -0.015      -0.001
dRz (mas/y)   0.005      0.003       0.002
dTx (m/y)    -0.0009    -0.0007     -0.0002
dTy (m/y)     0.0000     0.0001     -0.0001
dTz (m/y)    -0.0020    -0.0019      0.0000
dScl (ppb/y)  0.17       0.19       -0.02
                     
	Note, the differences are all well within the transformation 
parameters standard deviation (IGS Message 2432).

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            | 117 |  45 |        26.531 |         1.001 |        26.562 |
emr            |  46 |  33 |         5.401 |         1.002 |         5.411 |
esa            |  68 |  47 |        15.207 |         1.000 |        15.207 |
gfz            |  73 |  40 |        20.508 |         1.001 |        20.522 |
jpl            |  75 |  31 |         3.403 |         1.001 |         3.405 |
ngs            |  77 |  48 |        28.272 |         1.001 |        28.287 |
sio            | 131 |  45 |         2.363 |         1.001 |         2.364 |
JPL            | 143 |  48 |         2.321 |         1.001 |         2.323 |
mit            | 150 |  44 |         4.854 |         0.726 |         3.522 |
ncl            |  94 |  46 |         2.504 |         1.001 |         2.506 |
---------------|-----|-----|---------------|---------------|---------------|

5-2)      Solution Residuals weighted Average & R.M.S. :
========================================================

5-2-1)    With respect to ITRF97 Reference Frame stations:
=========================================================

Solution       |  Weighted Average (mm)    |        R.M.S. (mm)        |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod            |     1.0      0.1      0.4 |     3.3      3.4     10.3 |
emr            |    -3.6      1.2      1.5 |     8.1      8.7     16.2 |
esa            |    -3.9      0.2      1.6 |     8.6     12.8     20.5 |
gfz            |     1.5     -0.2      0.7 |     3.4      4.2     12.6 |
jpl            |    -0.6      0.1      0.8 |     3.7      4.2     10.0 |
ngs            |     0.6      0.7      1.9 |     5.9      6.4     13.7 |
sio            |    -1.7     -0.2      0.3 |     4.9      5.8     10.9 |
JPL            |     0.8     -0.1      1.3 |     3.0      3.8     10.6 |
mit            |     0.3     -0.1      0.7 |     2.6      3.3      7.6 |
ncl            |     0.3      0.0      0.3 |     2.5      3.0      4.5 |
---------------|---------------------------|---------------------------|

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

Solution       |  Weighted Average (mm)    |        R.M.S. (mm)        |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod            |     0.4      0.3     -2.0 |     1.9      2.6      9.7 |
emr            |    -4.1      0.3      0.6 |     7.1      9.3     11.5 |
esa            |    -5.5      0.6      0.7 |    10.6     13.8     17.5 |
gfz            |     0.6      0.0     -1.4 |     1.9      1.7      5.7 |
jpl            |    -1.3     -0.6     -0.4 |     2.8      2.1      5.1 |
ngs            |     0.4      0.6      0.1 |     6.1      6.8     10.2 |
sio            |    -2.9      0.3     -0.4 |     4.5      4.0      7.3 |
JPL            |     0.3      0.0      0.7 |     1.0      0.9      5.6 |
mit            |    -0.3     -0.1      0.8 |     1.1      1.1      4.5 |
ncl            |    -0.3      0.2     -0.1 |     1.1      1.4      4.9 |
ITR            |    -0.5      0.2     -1.2 |     2.8      3.9     10.1 |
---------------|---------------------------|---------------------------|

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

Solution       |  Weighted Average (mm)    |        R.M.S. (mm)        |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod            |     0.1      0.8     -3.8 |     3.1      3.2     13.1 |
emr            |    -3.8      0.2     -1.1 |     7.9      9.9     13.9 |
esa            |    -5.2      0.6      0.0 |    11.2     14.9     18.7 |
gfz            |     1.4     -0.4     -2.2 |     2.9      2.9      9.8 |
jpl            |    -0.9     -0.8     -1.2 |     3.1      3.6      9.5 |
ngs            |     1.1      0.4     -1.6 |     6.2      7.9     13.3 |
sio            |    -2.9      0.5     -2.4 |     6.9      7.6     17.5 |
JPL            |     0.4      0.2     -0.7 |     5.0      6.2     16.5 |
mit            |    -0.4      0.2     -0.6 |     5.0      6.3     16.2 |
ncl            |     0.0      0.0     -1.1 |     2.7      2.2      8.2 |
igs            |     0.1      0.2     -1.5 |     5.4      6.3     15.4 |
ITR            |     0.4      0.2     -1.1 |     2.7      3.1      9.7 |
---------------|---------------------------|---------------------------|

5-3)      7-Parameters Transformation: AC ----> ITRF97_IGS_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            |   0.021   -0.024    0.002      6.1    -10.3     33.9     2.24 |
emr            |  12.424    4.764   72.572      8.4    -39.8    131.2     1.81 |
esa            |   0.305   -0.256   -0.171    -21.9      6.2      2.2     0.58 |
gfz            |   0.016    0.005   -0.019     -0.1      1.1     -0.4     0.37 |
jpl            |   0.039   -0.007   -0.016     -2.6      0.6    -13.0     1.74 |
ngs            |  -0.140    0.081    0.084    -12.1     -6.8      7.8     0.84 |
sio            |  -0.377    0.020    0.264     -1.8    -18.7     85.5     0.98 |
JPL            |   0.005   -0.024    0.083     -0.6      0.9     -2.5     1.11 |
mit            |   0.004   -0.022   -0.007      0.0      0.4     -1.9     0.84 |
ncl            |  -0.005   -0.019    0.015      0.1     -0.4     -0.8     0.36 |
---------------|---------------------------------------------------------------|

5-3-2)    Sigmas : 
==================

Solution       |    R X      R Y      R Z      T X      T Y      T Z      SCL  |
               |   (mas)    (mas)    (mas)     (mm)     (mm)     (mm)    (ppb) |
---------------|---------------------------------------------------------------|
cod            |   0.060    0.060    0.067      1.6      1.6      1.5     0.24 |
emr            |   0.070    0.069    0.080      1.8      1.8      1.8     0.28 |
esa            |   0.059    0.059    0.066      1.5      1.5      1.5     0.24 |
gfz            |   0.063    0.064    0.071      1.6      1.6      1.6     0.26 |
jpl            |   0.072    0.070    0.080      1.9      1.9      1.8     0.29 |
ngs            |   0.059    0.058    0.066      1.5      1.5      1.5     0.24 |
sio            |   0.061    0.060    0.067      1.5      1.5      1.5     0.24 |
JPL            |   0.059    0.058    0.066      1.5      1.5      1.5     0.24 |
mit            |   0.062    0.061    0.071      1.6      1.6      1.6     0.25 |
ncl            |   0.060    0.060    0.066      1.5      1.5      1.5     0.24 |
---------------|---------------------------------------------------------------|

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

               |      X        Y        Z  |    s X      s Y      s Z  |
               |    (mm)     (mm)     (mm) |    (mm)     (mm)     (mm) |
---------------|---------------------------|---------------------------|
igs            |    -2.7     -6.6     -4.3 |     4.7      4.7      5.9 |
---------------|---------------------------|---------------------------|

5-5)      ERP Residuals Weighted Average & R.M.S. :
===================================================

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

Solution       |      UT       LOD       XPO      XPOR       YPO      YPOR  |
               |      us        us    .01mas    .01ma/d   .01mas    .01ma/d |
---------------|------------------------------------------------------------|
cod            |     ---      -13.6      -1.3       2.7      -8.3       2.4 |
emr            |     ---       44.1     -22.3      93.7       3.2     -11.0 |
esa            |     ---       -1.0      15.1       -.8     -49.5       6.1 |
gfz            |     ---       -2.2       4.8       2.6       3.1        .7 |
jpl            |     ---       16.0       -.1      -3.0       1.2      -5.0 |
ngs            |     ---       38.6     -14.0     -37.8      19.5      15.1 |
sio            |     ---      -22.7      -9.3      -1.2        .2      -6.8 |
JPL            |     ---        ---       ---       ---       ---       --- |
mit            |     ---       -1.8     -23.1        .3       5.9        .1 |
ncl            |     ---        ---       ---       ---       ---       --- |
ITR            |     ---        ---       ---       ---       ---       --- |
---------------|------------------------------------------------------------|

5-5-2)    R.M.S. :
==================

Solution       |      UT       LOD       XPO      XPOR       YPO      YPOR  |
               |      us        us    .01mas    .01ma/d   .01mas    .01ma/d |
---------------|------------------------------------------------------------|
cod            |     ---       18.1       4.5      13.2       9.3       6.8 |
emr            |     ---       48.2      28.8     106.6      12.7      36.9 |
esa            |     ---       12.9      17.4      31.4      51.0      90.2 |
gfz            |     ---        6.1       5.2      12.9       4.7      13.8 |
jpl            |     ---       19.9       2.7      31.9       5.4      15.3 |
ngs            |     ---      185.3      16.8      65.3      24.7      49.9 |
sio            |     ---       23.9      11.0      12.5      11.4      16.0 |
JPL            |     ---        ---       ---       ---       ---       --- |
mit            |     ---        3.2      23.1       3.4       5.9       2.5 |
ncl            |     ---        ---       ---       ---       ---       --- |
ITR            |     ---        ---       ---       ---       ---       --- |
---------------|------------------------------------------------------------|

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

Threshold set at 5 sigmas

 Solution             Solution           |  Station   |    N       E       U  |
              Minus                      |code id soln|   (mm)    (mm)    (mm)|
-----------------------------------------|------------|-----------------------|
                                         |            |                       |
esa10237.snx         jpl10237.snx        |MADR  A ----|   39.9   -45.5   -13.2|
                                         |            |                       |
esa10237.snx         JPL1023g.snx        |MADR  A ----|   38.1   -42.2    -9.7|
                                         |            |                       |
IGS99P32.snx         sio10237.snx        |MADR  A ----|   21.0   -20.0    -1.1|
                                         |            |                       |
IGS99P32.snx         mit1023g.snx        |MADR  A ----|   18.3   -21.7    -5.0|
IGS99P32.snx         mit1023g.snx        |RIOP  A ----|  -34.5    70.7   -21.0|
IGS99P32.snx         mit1023g.snx        |YAKA  A ----|  -19.2     8.2   -17.1|
                                         |            |                       |
IGS99P32.snx         ncl1023g.snx        |YAKA  A ----|  -19.8     8.7   -14.4|
-----------------------------------------|------------|-----------------------|

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

IERS DOMES NO    COD    NRC    ESA    GFZ    JPL    NOA    SIO
============= ====== ====== ====== ====== ====== ====== ======
    12309M002 MDVO A        MDVO B                      MDVO A
    40114M001 NRC1 A NRC2 A NRC1 A        NRC1 A        NRC1 A
    40405S031 GOL2 A GOL2 A GOL2 A GOL2 A GOL2 A GOLD B GOL2 A
    50103M108 TID2 A TID2 A TIDB A TID2 A TID2 A TIDB A TID2 A
    30302M007 HARK A        HARK B HARK A        HARK A 
    30302????                             HARK A
    31303M002 MAS1 A MASP B MASP A               MASP B MAS1 A
    42202M005 AREQ A AREQ B AREQ A AREQ A AREQ A AREQ B AREQ A
    22306M002 IISC A        IISC B IISC A        IISC B IISC A
    13407S012               MADR A        MAD2 A MADR A MAD2 A
 
MISSING IERS DOMES NOS AT GFZ:
-----------------------------
  BISH A
 
MISSING IERS DOMES NOS AT SIO:
-----------------------------
  GILB A  KABR A  HARK A

IERS DOMES NO    JPL    MIT    NCL
============= ====== ====== ======
    13407S012 MAD2 A MAD2 A 
              MADR A MADR A 
    31303M002 MAS1 A        MAS1 A
    31303M001        MAS1 A 
    12309M002 MDVO A
    12309M001        MDVO A 
    40114M001 NRC1 A NRC2 A NRC1 A
              NRC2 A NRC1 A 
    50103M108 TID2 A TID2 A TID2 A
              TIDB A TIDB A 
 
MISSING IERS DOMES NOS AT JPL:
-----------------------------
  INEG A
 
MISSING IERS DOMES NOS AT MIT:
-----------------------------
  BISH A  GILB A  KABR A  HARK A

--

[Mailed From: Remi Ferland <[email-masked]>]