Subject: [IGSREPORT-18254] Wk 1567 IGS SINEX Combination
From: "Paul Rebischung" <[email-masked]>
To: <[email-masked]>, <[email-masked]>
Date: Thu, 4 Feb 2010 10:25:09 +0100

******************************************************************************
IGS Electronic Report   04 Feb 01:25:42 PST 2010      Message Number 18254
******************************************************************************

Authors: B. Garayt, P. Rebischung

===============================================================

 Combined AC solution for GPS week 1567 - 10/01/17 to 10/01/23

===============================================================

1) Contacts:

============

e-mail: [email-masked]

Tel:    0033143988197 (Bruno Garayt)

Fax:    0033143988450

2) Products:

============

All products are available at:

  CDDIS: ftp://cddis.gsfc.nasa.gov/gps/products

  SOPAC: ftp://garner.ucsd.edu/pub/products

  IGN:   ftp://igs.ensg.eu/pub/igs/products

         ftp://igs.ign.fr/pub/igs/products

igs10P1567.snx  Combined weekly solution

igs10P1567.erp  Daily Earth Rotation Parameters

igs10P1567.sum  This file

igs10P1567.itr  Residuals between AC solutions and IGS05 for the RF stations

igs10P1567.res  Residuals between AC solutions and combined weekly solution

IGS10P03.snx    Cumulative combined solution

IGS10P03.res    Residuals between AC solutions and cumulative solution

igs00p03.erp    Daily Earth Rotation Parameters since GPS week 860

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) Constrained AC solutions are unconstrained according to the information

     given in their SOLUTION/APRIORI blocks and then minimally constrained.

     AC solutions given in the form of a normal matrix (esa) are inverted by

     adding minimal constraints.

3-4) The weekly AC solutions are combined. The 7-parameters singularity is

     avoided by using internal constraints. Iterations are performed until
no

     residuals exceed 5 cm or 5 sigma.

3-5) The combined solution is compared to IGS05 propagated at current week

     (datum). Some outliers may be removed from the datum. Finally, the

     combined solution is aligned to the datum using a 7-parameters

     transformation.

3-6) The AC solutions NOT used in the combination are compared to the
combined

     solution in order to identify and remove outliers.

3-7) The weekly combined solution is added to the cumulative solution.

     Iterations are performed until no residuals exceed 3 cm or 3 sigma in
the

     weekly solution.

3-8) The updated cumulative solution is compared to IGS05 (datum). Some
outliers

     may be removed from the datum. Finally, the cumulative solution is
aligned

     to the datum using a 14-parameters transformation.

4) Remarks:

===========

     mit = mit15677.snx

     mig = mit1567g.snx

     ITR = IGS05.snx

     igs = igs10P1567.snx

     IGS = IGS10P03.snx

     grg, mit, ncl are not used in the combination.

     They are only used for comparison.

     Solutions with manual station deletion:

         cod  ETAD

         grg  INEG

     4-1) Starting with GPS week 1400, the solutions are aligned to the

          IGS05.snx realization of ITRF2005.

     4-2) Starting with GPS week 1078, UT1-UTC from IERS Bulletin A

          is included in the erp files.

     4-3) Starting with GPS week 1412, the accumulated ERP file has been

          changed from "igs00p02.erp" to "igs00p03.erp". The main changes

          are:

       1) Correction of the pole position from IGb00 to IGS05 using the

          transformation in:

              http://igscb.jpl.nasa.gov/mail/igsmail/2006/msg00178.html

       2) Marginal ERP's in GPS week 1161 were replaced by reprocessed

          values.

5) Results:

============

5-1)      AC (Variance Factor)^0.5 estimates:

=============================================

     At each iteration, the variance factor for solution s is estimated by :

     VF = (vs'*Ps*vs)/fs   with fs = nobss - tr(As*Q*As'*Ps)

                                vs : residuals of solution s

                                Ps : weight matrix of solution s

                                nobss : number of observations of solution s

                                As : design matrix of solution s

                                Q : total covariance matrix

     This variance factor is used to rescale the covariance matrix of
solution s

     for the next iteration.

     Another scale factor is computed for each solution s, by comparing it
to

     the official cumulative solution of previous week (IGS) :

     SF = (vs'*Ps*vs)/(3*nstas)   with vs : residuals of the comparison

                                       Ps : weight matrix of solution s

                                       nstas : number of common stations

Solution       |# sta| #RF |   Final VF    |       SF      |

---------------|-----|-----|---------------|---------------|

cod            | 223 |  65 |         7.140 |        36.907 |

emr            |  82 |  41 |         2.223 |         7.994 |

esa            | 138 |  46 |         2.658 |         6.065 |

gfz            | 186 |  63 |         2.969 |        13.667 |

jpl            | 113 |  46 |         6.255 |        12.901 |

mit            | 262 |  70 |         0.638 |         3.594 |

ngs            | 197 |  66 |        15.304 |        53.204 |

sio            | 254 |  68 |         0.844 |         3.736 |

grg            |  98 |  41 |        ------ |        11.656 |

mig            | 380 |  72 |        ------ |         3.587 |

ncl            | 223 |  69 |        ------ |         1.981 |

---------------|-----|-----|---------------|---------------|

5-2)      Solution Residuals weighted Average & STD:

====================================================

5-2-1)    With respect to the IGS05 stations:

=============================================

Solution       |  Weighted Average (mm)    |          STD (mm)         |

               |      N        E        U  |      N        E        U  |

---------------|---------------------------|---------------------------|

cod         65 |    -0.5     -0.1      0.3 |     3.7      3.1      8.8 |

emr         41 |     0.3      0.0      0.4 |     3.7      3.6     10.4 |

esa         46 |    -0.8     -0.1      0.6 |     3.6      3.2     10.6 |

gfz         63 |    -0.6     -0.1      0.2 |     3.6      3.3      9.4 |

jpl         46 |    -0.4     -0.1      0.0 |     3.8      4.0     10.6 |

mit         70 |    -0.0      0.0      0.5 |     3.8      3.7      9.5 |

ngs         66 |     0.0     -0.2      0.4 |     3.7      3.2     10.1 |

sio         68 |    -0.1     -0.0      0.3 |     4.3      3.4      9.5 |

grg         41 |    -1.2      0.1      0.1 |     4.3      3.3      9.1 |

mig         72 |    -0.4     -0.1      0.1 |     3.7      3.4      9.3 |

ncl         69 |    -0.1     -0.1      0.3 |     3.8      3.5      9.5 |

---------------|---------------------------|---------------------------|

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

=================================================

Solution       |  Weighted Average (mm)    |          STD (mm)         |

               |      N        E        U  |      N        E        U  |

---------------|---------------------------|---------------------------|

cod        223 |    -0.2     -0.0     -0.0 |     1.2      0.6      2.5 |

emr         82 |     0.4     -0.1     -0.1 |     1.3      0.8      3.7 |

esa        138 |     0.0      0.1      0.3 |     2.5      1.4      4.6 |

gfz        186 |    -0.0     -0.0      0.0 |     0.7      0.8      2.3 |

jpl        113 |     0.1      0.1     -0.1 |     1.6      2.7      5.9 |

mit        262 |     0.2      0.0      0.0 |     0.5      0.5      1.6 |

ngs        197 |     0.2      0.1      0.0 |     1.4      1.5      3.2 |

sio        254 |     0.2      0.0      0.0 |     1.3      0.8      2.5 |

grg         98 |    -1.9     -0.0      0.2 |     3.5      2.8      6.1 |

mig        380 |     0.1      0.0     -0.0 |     0.3      0.3      0.8 |

ncl        223 |     0.2      0.0      0.0 |     0.5      0.7      1.6 |

ITR         72 |     0.5     -0.1     -0.2 |     3.7      3.4      9.3 |

---------------|---------------------------|---------------------------|

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

=====================================================

Solution       |  Weighted Average (mm)    |          STD (mm)         |

               |      N        E        U  |      N        E        U  |

---------------|---------------------------|---------------------------|

cod        197 |    -1.0     -0.4      0.4 |     2.7      2.8      8.3 |

emr         80 |    -0.1     -0.2      0.1 |     2.7      2.9      8.3 |

esa        123 |    -0.8     -0.1      0.6 |     3.0      2.7      9.4 |

gfz        181 |    -0.7     -0.3      0.1 |     2.4      2.8      7.7 |

jpl        109 |    -1.0     -0.1     -0.1 |     3.3      4.2      9.3 |

mit        235 |    -0.7     -0.3      0.1 |     2.6      3.1      7.8 |

ngs        190 |    -0.5     -0.3      0.2 |     2.7      3.1      9.1 |

sio        239 |    -0.6     -0.3      0.5 |     3.2      3.0      8.0 |

grg         97 |    -2.7     -0.3      0.1 |     3.7      3.8     10.0 |

mig        307 |    -0.9     -0.1     -0.0 |     2.9      3.2      8.0 |

ncl        219 |    -0.6     -0.3      0.1 |     2.6      3.0      7.9 |

igs        308 |    -1.0     -0.2      0.0 |     2.7      3.1      7.8 |

ITR        116 |    -0.8     -0.1     -0.1 |     2.8      3.1     11.6 |

---------------|---------------------------|---------------------------|

5-3)      7-Parameters Transformation: AC ----> IGS05.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            |  -0.016    0.011   -0.024     -0.3      1.1      0.9
-0.10 |

emr            |   0.022    0.021    0.049      7.1      4.2      3.3
0.41 |

esa            |   0.098   -0.072    0.045      6.4      6.0      0.4
0.09 |

gfz            |   0.007    0.007   -0.006     -0.1      1.5      0.9
-0.02 |

jpl            |   0.002   -0.021   -0.046      8.0      3.0      4.6
0.25 |

mit            |   0.020   -0.014   -0.031      8.0      1.1     -2.3
0.17 |

ngs            |  -0.026   -0.146   -0.004      9.6     -1.8     -7.5
0.04 |

sio            |   0.045   -0.058   -0.012      4.6      4.3      0.9
0.31 |

grg            |   0.064   -0.009    0.040     10.0     17.9      7.7
0.77 |

mig            |   0.037   -0.000    0.002      1.0      2.5      1.7
0.18 |

ncl            |  -0.004    0.052    0.035     -0.5      0.6      1.5
0.16 |

igs            |   0.000    0.000    0.000      0.0      0.0      0.0
0.13 |

---------------|------------------------------------------------------------
---|

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            |   0.030    0.031    0.034      0.8      0.8      0.8
0.12 |

emr            |   0.041    0.042    0.050      1.1      1.1      1.1
0.17 |

esa            |   0.038    0.041    0.046      1.0      1.0      1.0
0.16 |

gfz            |   0.032    0.033    0.036      0.9      0.9      0.8
0.13 |

jpl            |   0.041    0.042    0.047      1.1      1.1      1.1
0.17 |

mit            |   0.031    0.032    0.035      0.8      0.8      0.8
0.13 |

ngs            |   0.031    0.032    0.034      0.8      0.8      0.8
0.13 |

sio            |   0.032    0.033    0.035      0.8      0.8      0.8
0.13 |

grg            |   0.038    0.041    0.046      1.0      1.0      1.0
0.16 |

mig            |   0.030    0.031    0.033      0.8      0.8      0.8
0.12 |

ncl            |   0.031    0.032    0.035      0.8      0.8      0.8
0.13 |

igs            |   0.000    0.000    0.000      0.0      0.0      0.0
0.16 |

---------------|------------------------------------------------------------
---|

5-4)      Geocenter:

====================

               |      X        Y        Z  |    s X      s Y      s Z  |

               |    (mm)     (mm)     (mm) |    (mm)     (mm)     (mm) |

---------------|---------------------------|---------------------------|

igs            |     9.4      1.6     -3.3 |     1.9      1.7      4.3 |

---------------|---------------------------|---------------------------|

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            |     ---        ---       ---       ---       ---       ---
|

emr            |     ---       10.5       3.6      15.8      -4.2      23.1
|

esa            |     ---       -5.8       2.5      18.6      -3.0      24.9
|

gfz            |     ---       -3.2       1.3       9.2       0.3       4.5
|

jpl            |     ---      -19.9       4.6       9.3      -3.9      36.4
|

mit            |     ---        2.0       0.9      -7.9       2.9     -10.9
|

ngs            |     ---       -1.0      -2.5       4.2      -2.9       9.7
|

sio            |     ---       10.2       2.3       1.6      -0.6     -17.3
|

grg            |     ---      -19.7      -2.3      33.9      -1.6      20.6
|

mig            |     ---        8.5       1.0       4.2      -2.4     -13.0
|

ncl            |     ---        ---       ---       ---       ---       ---
|

BuA            |     ---       -7.6      -1.1      10.6       3.1      32.6
|

---------------|------------------------------------------------------------
|

5-5-2)    STD:

==============

Solution       |      UT       LOD       XPO      XPOR       YPO      YPOR
|

               |      us        us    .01mas    .01ma/d   .01mas    .01ma/d
|

---------------|------------------------------------------------------------
|

cod            |     ---        ---       ---       ---       ---       ---
|

emr            |     ---        9.6       1.9       7.4       2.0      13.9
|

esa            |     ---       10.9       0.8      10.2       2.3      11.7
|

gfz            |     ---        5.1       1.8       9.0       1.9      14.5
|

jpl            |     ---       10.9       1.0      13.7       1.2       9.9
|

mit            |     ---        2.0       0.6       3.8       1.2       4.3
|

ngs            |     ---        9.2       3.2       7.6       7.2      19.5
|

sio            |     ---        1.2       1.2       3.4       1.5       6.9
|

grg            |     ---       10.8       3.1       9.0       3.2      18.6
|

mig            |     ---        0.9       1.2       3.5       1.5       6.2
|

ncl            |     ---        ---       ---       ---       ---       ---
|

BuA            |     ---       16.1       5.6       7.0       5.1      10.2
|

---------------|------------------------------------------------------------
|

5-6)      Satellite Antenna Offset Residuals weighted Average & STD:

====================================================================

     No Satellite phase center ... 

5-7)      Outliers:

===================

     Outliers may be rejected at different stages of the processing:

       - During the combination (stage 3-4)), outliers may be removed from
the

         weekly AC solutions. Thresholds are set to 5 cm and 5 sigma.

       - During stage 3-6), outliers may be removed from the AC solutions
NOT

         included in the combination. Thresholds are set to 5 cm and 5
sigma.

       - During the stacking of the weekly combined solution on the
cumulative

         solution (stage 3-7)), outliers may be removed from the weekly
solution.

         Thresholds are set to 3 cm and 3 sigma.

Solution         Stage of rejection      |  Station   |    N       E       U
|

                                         |code id soln|   (mm)    (mm)
(mm)|

-----------------------------------------|------------|---------------------
--|

                                         |            |
|

cod15677.snx     Combination: Iter. 1    |KHAJ  A    2|    1.1    -0.5
10.5|

mit15677.snx     Combination: Iter. 1    |WTZJ  A    2|    2.5     6.3
107.1|

esa15677.snx     Combination: Iter. 2    |ETDD  A    2|   -5.3    -0.6
-46.4|

gfz15677.snx     Combination: Iter. 2    |SCH2  A    2|    0.1    -0.5
13.2|

ngs15677.snx     Combination: Iter. 2    |TIXJ  A    2|    8.2    -2.1
24.3|

                                         |            |
|

grg15677.snx     Comp. to igs10P1567.snx |ASPA  A    3|  -71.0   -25.1
31.1|

mit1567g.snx     Comp. to igs10P1567.snx |ETAD  A    1|   -1.4     3.3
45.0|

mit1567g.snx     Comp. to igs10P1567.snx |WTZJ  A    2|    0.4    -0.0
10.2|

                                         |            |
|

igs10P1567.snx   Stacking:    Iter. 1    |ARTU  A    3|   10.0    -0.6
-33.9|

igs10P1567.snx   Stacking:    Iter. 1    |DUBO  A    4|   -3.7    -2.6
31.4|

igs10P1567.snx   Stacking:    Iter. 1    |EIL1  A    1|   -1.8    15.1
38.0|

igs10P1567.snx   Stacking:    Iter. 1    |MTBG  A    3|    9.6    -0.4
-45.4|

igs10P1567.snx   Stacking:    Iter. 1    |WLSN  A    3|    5.4    11.0
32.4|

                                         |            |
|

-----------------------------------------|------------|---------------------
--|