Subject: [IGSREPORT-7209] Wk 1061 IGS SINEX Combination
From: Remi Ferland <[email-masked]>
To: [email-masked] (IGS Report Mailbox)
Date: Fri, 26 May 2000 13:38:26 EDT

******************************************************************************
IGS Electronic Report   26 May 10:38:44 PDT 2000      Message Number 7209
******************************************************************************

Author:  R. Ferland , D. Hutchison

===================================================================
 Combined AC  solution for GPS week 1061 -  00/05/07 to 00/05/13
===================================================================

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

igs00P1061.snx  Combined weekly solution. 
igs00P1061.erp  Daily Earth Rotation Parameters.
igs00p02.erp    Daily Earth Rotation Parameters since GPS week 1013.
IGS00P19.snx    Cumulative Combined solution. 
igs00P1061.sum  This file.
igs00P1061.itr  Residuals between the AC and the ITRF97 for the RF stations.
igs00P1061.res  Residuals between the AC and the Combined Weekly solution.
IGS00P19.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 = igs00P1061.snx
     IGS = IGS00P19.snx

     BuA = IERS Bulletin A

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

     Exceptionnaly, one AC is missing. Note that the GNAACs NCL and the JPL
        were eager to submit their current combination. To avoid  several
	hours of extra delays from my part to add the NCL and JPL, I am
	submitting the most up to date combination. This, I hope will
	allow the people at code to complete their orbit combination at
	a reasonnable time.

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            | 122 |  43 |        28.900 |         1.000 |        28.899 |
emr            |  37 |  20 |         3.298 |         1.001 |         3.301 |
esa            |  57 |  39 |        11.458 |         1.000 |        11.458 |
gfz            |  67 |  35 |        18.866 |         1.000 |        18.865 |
jpl            |  77 |  36 |         3.967 |         1.000 |         3.966 |
sio            | 126 |  46 |         1.847 |         1.000 |         1.847 |
mit            | 150 |  44 |         2.923 |         0.888 |         2.595 |
igs            | 137 |  48 |         1.419 |         1.000 |         1.419 |
---------------|-----|-----|---------------|---------------|---------------|

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

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

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod         42 |    -0.8     -0.6      0.8 |     2.7      5.2     12.5 |
emr         19 |    -0.4      0.4      0.9 |     7.2      7.1     10.9 |
esa         38 |     0.0     -0.2     -0.4 |     5.4      6.7     16.9 |
gfz         34 |    -0.2     -0.3      0.8 |     4.1      5.5     12.1 |
jpl         35 |    -2.6      0.2      1.3 |     4.3      5.4     14.2 |
sio         44 |    -1.5      0.3      0.1 |     3.3      5.8     11.8 |
mit         43 |    -0.1     -0.1      0.5 |     4.2      4.2      7.2 |
---------------|---------------------------|---------------------------|

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

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod        117 |     0.0     -0.6      1.2 |     2.2      2.5      9.6 |
emr         36 |     2.2     -0.3      1.7 |     5.5      4.8      6.6 |
esa         57 |     1.1     -1.0     -2.7 |     4.4      4.0      9.3 |
gfz         63 |     1.5      0.1     -0.9 |     1.7      2.2      5.1 |
jpl         74 |    -1.2     -0.7      0.2 |     2.1      3.0      7.5 |
sio        119 |    -0.6      0.0      1.1 |     2.1      2.4      5.7 |
mit        129 |     0.3     -0.2      3.1 |     2.1      1.7      7.4 |
ITR         47 |     0.4      0.2     -1.0 |     5.8      5.5     12.8 |
---------------|---------------------------|---------------------------|

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

Solution       |  Weighted Average (mm)    |          STD (mm)         |
               |      N        E        U  |      N        E        U  |
---------------|---------------------------|---------------------------|
cod        117 |    -1.4      0.5     -0.9 |     3.9      3.5     12.1 |
emr         36 |     1.0      0.2      0.0 |     5.7      6.1      7.4 |
esa         57 |     0.3     -0.4     -4.7 |     5.6      5.2     12.7 |
gfz         63 |     0.2      0.6     -2.9 |     2.2      3.2      6.7 |
jpl         74 |    -2.2      0.2     -0.8 |     3.5      4.4     10.0 |
sio        119 |    -1.8      1.2     -1.0 |     3.1      4.0      8.2 |
mit        130 |    -0.7      0.8      1.5 |     4.2      2.6      8.6 |
igs        137 |    -1.2      0.9     -1.9 |     2.9      2.8      6.8 |
ITR         51 |     0.5      0.4     -1.5 |     2.8      3.7     10.6 |
---------------|---------------------------|---------------------------|

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            |  -0.010    0.049   -0.052      8.6     -4.9    -11.3     3.06 |
emr            |  -0.003    0.041   -0.039     12.7     -6.2    -53.6     1.66 |
esa            |   0.029   -0.025   -0.001     -2.5     11.8     13.9     1.75 |
gfz            |  -0.094    0.026    0.006     -1.4      2.3     -4.4     1.73 |
jpl            |   0.024   -0.012    0.020     -5.3     -4.4    -21.2     2.44 |
sio            |  -0.134    0.025    0.186      9.1     -6.3     59.6     2.26 |
mit            |  -0.023   -0.012    0.020     -0.9      0.0     -2.2     1.08 |
---------------|---------------------------------------------------------------|

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            |   0.060    0.062    0.070      1.6      1.6      1.6     0.25 |
emr            |   0.086    0.090    0.107      2.3      2.3      2.3     0.36 |
esa            |   0.067    0.067    0.071      1.7      1.7      1.7     0.27 |
gfz            |   0.067    0.067    0.079      1.7      1.7      1.7     0.27 |
jpl            |   0.066    0.066    0.074      1.7      1.7      1.7     0.27 |
sio            |   0.058    0.059    0.067      1.5      1.5      1.5     0.24 |
mit            |   0.060    0.061    0.070      1.6      1.6      1.6     0.24 |
---------------|---------------------------------------------------------------|

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

               |      X        Y        Z  |    s X      s Y      s Z  |
               |    (mm)     (mm)     (mm) |    (mm)     (mm)     (mm) |
---------------|---------------------------|---------------------------|
igs            |     2.7     -0.6    -16.2 |     6.3      6.3      8.7 |
---------------|---------------------------|---------------------------|

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            |     ---      -17.3      -5.4       1.4       2.7       2.5 |
emr            |     ---      -11.3     -11.1     -60.1       9.0       3.1 |
esa            |     ---      -32.6       4.8       -.3     -14.9      -1.5 |
gfz            |     ---       -6.6      -5.0      -1.8       5.4      -2.6 |
jpl            |     ---       12.7      -5.8      32.7       3.5     -17.5 |
sio            |     ---       33.9       6.2      -1.7      -1.5      -1.7 |
mit            |     ---      -13.4        .1        .1      -4.2        .1 |
ITR            |     ---        ---       ---       ---       ---       --- |
BuA            |     ---      -33.2      -1.8       -.9      16.5       1.2 |
---------------|------------------------------------------------------------|

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

Solution       |      UT       LOD       XPO      XPOR       YPO      YPOR  |
               |      us        us    .01mas    .01ma/d   .01mas    .01ma/d |
---------------|------------------------------------------------------------|
cod            |     ---       12.4       2.6       9.3       4.3       5.3 |
emr            |     ---       26.9      11.0      21.0       8.4      31.6 |
esa            |     ---       26.1       6.1      26.0       6.8      11.4 |
gfz            |     ---       12.2       2.9       5.4       3.6       6.0 |
jpl            |     ---       39.3       5.2      21.3       7.5      10.9 |
sio            |     ---       12.8       4.7       9.1       4.9       8.8 |
mit            |     ---       12.9       1.6       2.6       1.2       3.7 |
ITR            |     ---        ---       ---       ---       ---       --- |
BuA            |     ---        8.5       5.9      10.3       3.8       9.0 |
---------------|------------------------------------------------------------|

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

Thresholds set at 5 sigmas and 50 mm.

 Solution             Solution           |  Station   |    N       E       U  |
              Minus                      |code id soln|   (mm)    (mm)    (mm)|
-----------------------------------------|------------|-----------------------|
                                         |            |                       |
ITRF97_IGS_RS51.snx  emr10617.snx        |MALI  A ----|    3.4     7.3   -55.7|
                                         |            |                       |
ITRF97_IGS_RS51.snx  esa10617.snx        |MCM4  A ----|   11.5     6.5   -56.2|
                                         |            |                       |
ITRF97_IGS_RS51.snx  gfz10617.snx        |ZWEN  A ----|   38.7   -37.3    36.6|
                                         |            |                       |
IGS00P18.snx         cod10617.snx        |LAMA  A ----|   10.5   -23.3    -1.4|
                                         |            |                       |
IGS00P18.snx         gfz10617.snx        |ARTU  A ----|    2.6     0.2   -39.8|
                                         |            |                       |
IGS00P18.snx         jpl10617.snx        |ARTU  A ----|   -1.3     1.5   -38.4|
                                         |            |                       |
IGS00P18.snx         sio10617.snx        |LAMA  A ----|   10.8   -22.0   -11.2|
IGS00P18.snx         sio10617.snx        |MADR  A ----|    0.4    18.9     6.4|
IGS00P18.snx         sio10617.snx        |ZWEN  A ----|   31.7   -27.9    36.8|
                                         |            |                       |
IGS00P18.snx         mit1061g.snx        |LAMA  A ----|    9.5   -21.1    -1.5|
-----------------------------------------|------------|-----------------------|

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

IERS DOMES NO    cod    emr    esa    gfz    jpl    sio    IGS    igs
============= ====== ====== ====== ====== ====== ====== ====== ======
    31303M002 MAS1 A MAS1 A MASP A MAS1 A MAS1 A MAS1 A MAS1 A MAS1 A
    12353M001 YAKZ A                      YAKZ A YAKZ A YAKA A YAKA A
    40405S031 GOL2 A        GOL2 A GOL2 A        GOL2 A GOLD A GOLD A
    42005M001 GALA A        GALA B GALA A GALA A GALA A GALA A GALA A
    50103M108 TID2 A        TID2 A TID2 A TID1 A TID2 A TIDB A TIDB A
    13407S012                                    MAD2 A MADR A 
 
MISSING IERS DOMES NOS AT gfz:
-----------------------------
  BISH A
IERS DOMES NO    mit    IGS    igs
============= ====== ====== ======
    13407S012 MAD2 A MADR A 
    31303M001 MAS1 A
    31303M002        MAS1 A MAS1 A
    40405S031 GOL2 A GOLD A GOLD A
    50103M108 TID2 A TIDB A TIDB A
              TID1 A
    12353M001 YAKZ A YAKA A YAKA A
    12309M001 MDVO A
    12309M002        MDVO A MDVO A
 
MISSING IERS DOMES NOS AT mit:
-----------------------------
  BISH A
--