Subject: [IGEXMail-0320] Wk 0981 IGEX Orbits Report
From: Weber Robert <[email-masked]>
Date: 03 May 1999 01:21:27

Precedence: bulk

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IGEX Electronic Mail    03-May-1999 01:21:27                   Message No 0320
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Author: Weber Robert <[email-masked]>
Subject: Wk 0981 IGEX Orbits Report

Author:   IGEX AC Coordinator

IGX Orbit Combination - Week 0981   (Oct 25, 1998 - Oct 31, 1998)

Contact: R. Weber ([email-masked]),

COMBINATION STRATEGY:

All satellite positions referring to one IGEX Analysis Center, one
satellite, and one week are used as pseudo-observations to establish a
seven-day arc. Usually, fifteen parameters (six initial conditions and
nine radiation pressure parameters) are estimated in this orbit
determination procedure per arc, satellite and center. The Earth
Orientation Parameters (EOPs) are fixed to the values of the Final IGS
(GPS) combination in our long-arc analysis.

The combined IGEX solution is then produced using weighted mean values for
all GLONASS satellite positions from all centers ( L1-norm ). 
The center-specific weights are based on the RMS values of the long-arc fit.

The seven parameters of the Helmert transformations between the individual
centers' solutions with respect to the combined solution are given for
each day and each center in Tables 2.0981.x.

PRODUCTS GENERATED:

The combined IGEX-ephemerides are written to daily files in the SP3
format. The satellite accuracy codes in the header are based on the
weighted RMS for each satellite. Note, that the result files contain all
satellites that were analyzed by at least one center. We refer to the
"REMARKS" section of the combination report, if a satellite or center was
excluded from the combination.

The following naming convention is used for the result files:

 IGX09810-6.SP3  IGEX Glonass ephemerides files for days 0-6
                 of GPS week 0981 in the SP3 format.
 IGX09817.SUM    Combination report for GPS week 0981.

REMARKS concerning the IGEX Orbit Combination:

1. The satellite clock values in the combined orbit files are broadcast
   clock values.
   The value of 999999.999999 microseconds, according to the sp3 format
   convention, is used to indicate that no clock solution is available.

2. The following orbit solutions were excluded from the combination because
   they were biasing the weighted average (generally indicated by long arc RMS).

                      | Centre | SAT list
                      +--------+---------------
                      |  ESA   |  10,16
                      |  MCC   |  12

3. The combined orbits refer to the IGS-realization of the ITRF96.

ORBIT COMBINATION AND EVALUATION STATISTICS:

Table 1 summarizes the statistics for the long-arc (seven days) analysis.
It gives for each satellite the position RMS for each individual center
and for the combined orbit.

Table 2 contains the transformation parameters w.r.t. the combination for
each center and each day (Tables 2.0981.0-6).

Table 3 contains the daily RMS for each satellite and center together with
the computed satellite position RMS values for the combined orbits (Tables
3.0981.0-6).

Table 1.0981     GPS week : 0981   MJD: 51111.0-51117.0
         Long Arc Evaluation
         Satellite position RMS for the individual centers' orbits
         and for the combined orbit (IGX).
         "E" flags eclipsing satellites.
         "*" fewer than 7 days of data available.
         "--" not available in center solution.
         Units: cm.
----------------------------------
 SAT  |  BKG  COD  ESA  MCC  IGX |
------|--------------------------|
   3  |   19   22   14    5   10 |
   4  |   24   24   23    6   15 |
   6  |   28   32   21    7   18 |
   9  |   16   21   21    8   13 |
  10  |   63   67  619   --   63 |
  11  |   23   25   27   --   21 |
  12  |   40   42   --  999   40 |
  13  |   17   19   17   --   15 |
  15  |   15   23   15   --   11 |
  16  |   37   40  159    7   22 |
  17  |   35   38   27    5   26 |
  18  |   15   15   16   --   11 |
  20  |   12   15   28    7   13 |
  22  |   10   11   23    8   10 |
----------------------------------
MEDIAN|   21   24   21    7   15 |
----------------------------------

Table 2: Daily transformation parameters w.r.t. the combined IGX orbit.
         Units: meters (DX, DY, DZ, RMS), mas (RX, RY, RZ), ppb (SCL).

Table 2.0981.0   GPS week: 0981   Day: 0   MJD: 51111.0
-----------------------------------------------------
CENT STA|   DX   DY   DZ    RX    RY    RZ  SCL  RMS|
--------|-------------------------------------------|
bkg   16| 0.01 0.00 0.01  0.02 -0.26  0.05  0.3 0.33|
cod   17| 0.02 0.00-0.04  0.19 -0.53 -0.27 -0.9 0.37|
esa   26|-0.01 0.01 0.00  0.20 -0.26 -3.53  0.4 0.64|
mcc   --|-0.02 0.01 0.00 -0.06  0.21  1.38  0.3 0.21|
-----------------------------------------------------

Table 2.0981.1   GPS week: 0981   Day: 1   MJD: 51112.0
-----------------------------------------------------
CENT STA|   DX   DY   DZ    RX    RY    RZ  SCL  RMS|
--------|-------------------------------------------|
bkg   16| 0.00 0.01 0.00 -0.10 -0.13 -0.39  2.1 0.27|
cod   17| 0.00 0.01 0.01 -0.13 -0.25 -0.74  0.9 0.29|
esa   26|-0.01 0.01 0.05  0.24  0.33 -2.34  0.9 0.38|
mcc   --| 0.00-0.01-0.01 -0.01  0.13  1.02 -0.5 0.13|
-----------------------------------------------------

Table 2.0981.2   GPS week: 0981   Day: 2   MJD: 51113.0
-----------------------------------------------------
CENT STA|   DX   DY   DZ    RX    RY    RZ  SCL  RMS|
--------|-------------------------------------------|
bkg   16| 0.00-0.01 0.03  0.00  0.07  0.14  1.4 0.28|
cod   17| 0.00 0.00 0.07 -0.07  0.06 -1.22  0.8 0.34|
esa   26|-0.01 0.01 0.08  0.12  0.05 -1.26  1.5 0.31|
mcc   --| 0.01-0.01-0.03 -0.01  0.05  0.56 -0.7 0.11|
-----------------------------------------------------

Table 2.0981.3   GPS week: 0981   Day: 3   MJD: 51114.0
-----------------------------------------------------
CENT STA|   DX   DY   DZ    RX    RY    RZ  SCL  RMS|
--------|-------------------------------------------|
bkg   16| 0.00 0.00 0.01  0.04 -0.24  0.09 -0.4 0.13|
cod   17| 0.00-0.01-0.01  0.20 -0.34 -0.18 -0.6 0.16|
esa   26| 0.01 0.01 0.00 -0.17  0.87 -0.34  1.0 0.28|
mcc   --|  --   --   --    --    --    --    --  -- |
-----------------------------------------------------

Table 2.0981.4   GPS week: 0981   Day: 4   MJD: 51115.0

-----------------------------------------------------
CENT STA|   DX   DY   DZ    RX    RY    RZ  SCL  RMS|
--------|-------------------------------------------|
bkg   16| 0.00 0.01 0.01  0.13 -0.20  0.57  0.5 0.25|
cod   17|-0.01 0.01 0.05  0.09 -0.22  1.31 -0.9 0.25|
esa   26| 0.00-0.01 0.06  0.09  0.05 -0.05  0.5 0.34|
mcc   --| 0.00 0.00-0.01 -0.02  0.04 -0.27 -0.2 0.10|
-----------------------------------------------------

Table 2.0981.5   GPS week: 0981   Day: 5   MJD: 51116.0
-----------------------------------------------------
CENT STA|   DX   DY   DZ    RX    RY    RZ  SCL  RMS|
--------|-------------------------------------------|
bkg   16| 0.00 0.00 0.05  0.04 -0.11 -0.32  1.6 0.16|
cod   17| 0.01 0.00-0.04 -0.02 -0.12 -0.37 -1.9 0.17|
esa   26|-0.01 0.00-0.01 -0.04  0.20  0.12  0.3 0.21|
mcc   --|  --   --   --    --    --    --    --  -- |
-----------------------------------------------------

Table 2.0981.6   GPS week: 0981   Day: 6   MJD: 51117.0
-----------------------------------------------------
CENT STA|   DX   DY   DZ    RX    RY    RZ  SCL  RMS|
--------|-------------------------------------------|
bkg   16| 0.01 0.00 0.01  0.07 -0.18  0.95 -1.6 0.24|
cod   17| 0.00 0.01 0.01  0.21 -0.31  0.82 -3.0 0.29|
esa   26| 0.02 0.00 0.07  0.35 -0.08  0.70  0.6 0.24|
mcc   --|-0.01 0.00-0.01 -0.09  0.11 -0.21  0.1 0.08|
-----------------------------------------------------

Table 3: Daily RMS difference w.r.t. combination per satellite and center.
         The IGX column gives the weighted RMS of the combination.
         "E" marks eclipsing satellites.
         Units: cm.

Table 3.0981.0   GPS week: 0981   Day: 0   MJD: 51111.0

          Weighted Average
------------------------------
 SAT  | bkg cod esa mcc  IGX |
------|----------------------|
   3  |  34  29  37   8   26 |
   4  |  45  42  45   8   26 |
   6  |  30  31  34   5   26 |
   9  |  14  17  59  10   13 |
  10  |   8   9  --  --    6 |
  11  |  11   6  18  --   13 |
  12  |  14  15  --  --   13 |
  13  |  18   6  16  --   13 |
  15  |  33  41  50  --   52 |
  16  |  25  37  --   2   26 |
  17  |  46  51  85  --   52 |
  18  |  19  20  43  --   26 |
  20  |  20  28  44  15   26 |
  22  |  20  26 117  34   26 |
------------------------------
Median|  20  27  44   8      |
------------------------------

Table 3.0981.1   GPS week: 0981   Day: 1   MJD: 51112.0

          Weighted Average
------------------------------
 SAT  | bkg cod esa mcc  IGX |
------|----------------------|
   3  |  31  33  32   7   26 |
   4  |  34  37  29   5   26 |
   6  |  30  42  37   8   26 |
   9  |  16  21  53  13   13 |
  10  |   8   9  --  --    6 |
  11  |  14  11  31  --   13 |
  12  |  13  15  --  --   13 |
  13  |   9   9  12  --   13 |
  15  |  14  18  21  --   13 |
  16  |  35  34  --   2   26 |
  17  |  29  41  58   2   26 |
  18  |  16  12  31  --   13 |
  20  |  11  13  37   8   13 |
  22  |  16  20  25  21   26 |
------------------------------
Median|  16  19  31   8      |
------------------------------

Table 3.0981.2   GPS week: 0981   Day: 2   MJD: 51113.0

          Weighted Average
 SAT  | bkg cod esa mcc  IGX |
------|----------------------|
   3  |  27  38  16   5   13 |
   4  |  36  33  38   6   26 |
   6  |  21  55  38   8   26 |
   9  |  17  26  25   9   26 |
  10  |   6   7  --  --    6 |
  11  |  10  12  24  --   13 |
  12  |  13  15  --  --   13 |
  13  |   8   8  10  --   13 |
  15  |  15   9  17  --   13 |
  16  |  31  34  --   2   26 |
  17  |  45  51  41   3   26 |
  18  |  17   8  27  --   13 |
  20  |   9  11  22   5   13 |
  22  |  18  13  30  20   13 |
------------------------------
Median|  17  14  25   6      |
------------------------------

Table 3.0981.3   GPS week: 0981   Day: 3   MJD: 51114.0

          Weighted Average
 SAT  | bkg cod esa mcc  IGX |
------|----------------------|
   3  |  12   9   9  --   13 |
   4  |  17  14  29  --   13 |
   6  |   9  28  16  --   13 |
   9  |  10  11  21  --   13 |
  10  |   7   8  --  --    6 |
  11  |   8   6  16  --    6 |
  12  |   4   4  --  --    6 |
  13  |   7  10  14  --   13 |
  15  |  12   6  14  --   13 |
  16  |  12  14  --  --   13 |
  17  |  12  24  17  --   13 |
  18  |   8   7  17  --    6 |
  20  |   8   5  60  --    6 |
  22  |   6   6  16  --    6 |
------------------------------
Median|   9   9  17  --      |
------------------------------

Table 3.0981.4   GPS week: 0981   Day: 4   MJD: 51115.0

          Weighted Average
 SAT  | bkg cod esa mcc  IGX |
------|----------------------|
   3  |  21  13  13   3   13 |
   4  |  26  29  18   3   13 |
   6  |  18  24  17   3   13 |
   9  |  25  21  12   9   13 |
  10  |  17  19  --  --   13 |
  11  |  11   8  23  --    6 |
  12  |   9  10  --  --    6 |
  13  |   6   7  10  --    6 |
  15  |  11   8  13  --    6 |
  16  |  17  23  --   1   13 |
  17  |  33  29  25   2   26 |
  18  |  10  12  22  --   13 |
  20  |  21  21  63   9   26 |
  22  |  18  18  18  21   26 |
------------------------------
Median|  18  19  18   3      |
------------------------------

Table 3.0981.5   GPS week: 0981   Day: 5   MJD: 51116.0

          Weighted Average
 SAT  | bkg cod esa mcc  IGX |
------|----------------------|
   3  |  16   7  11  --   13 |
   4  |   8   3   7  --    6 |
   6  |  28  24  26  --   26 |
   9  |   9   7  18  --   13 |
  10  |  26  30  --  --   26 |
  11  |   8   7  18  --    6 |
  12  |  10  11  --  --   13 |
  13  |   6   7   8  --    6 |
  15  |  10   9  12  --   13 |
  16  |   4   4  --  --    6 |
  17  |  12  17  13  --    6 |
  18  |   7   6  13  --    6 |
  20  |   6   6  28  --    6 |
  22  |   8   6  25  --    6 |
------------------------------
Median|   9   7  13  --      |
------------------------------

Table 3.0981.6   GPS week: 0981   Day: 6   MJD: 51117.0

          Weighted Average
 SAT  | bkg cod esa mcc  IGX |
------|----------------------|
   3  |  17  17  19   9   13 |
   4  |  17  16  18   2   13 |
   6  |  28  42  20   5   26 |
   9  |  27  27  25  13   26 |
  10  |   9  11  --  --   13 |
  11  |   9  15  16  --   13 |
  12  |  10  11  --  --   13 |
  13  |   9  11  17  --   13 |
  15  |   9   9  12  --    6 |
  16  |  20  33  --   2   13 |
  17  |  19  32  21   2   13 |
  18  |   5   7  12  --    6 |
  20  |  11  17  20   7   13 |
  22  |   9  12   9  12    6 |
------------------------------
Median|  11  16  18   6      |
------------------------------

 End of report: Week 0981

--
___________________________________________________________________________
Robert Weber                           Tel:    ++43-1-58801-12865               
Department for Theoretical Geodesy     Fax:    ++43-1-58801-12896              
University of Technology, Vienna       E-Mail: [email-masked]
Gusshausstrasse 27-29                          [email-masked]
A-1040 Vienna, Austria                         
___________________________________________________________________________