Subject: [IGSMAIL-254] Re-Evaluation of Weeks 0681 and 0682
From: J. Feltens
Date: 12 MAY 1993 08:29:00

IGS Electronic Mail       12-MAY-1993 08:29:00       Message Number 254
***********************************************************************

From: J. Feltens 
Subj: Re-Evaluation of Weeks 0681 and 0682
------------------------------------------

 -------------------------
 ANALYSIS CENTRE: ESA/ESOC
 -------------------------

 OUTLINE OF THE ESTIMATION OF GPS-ORBITS AND EARTH ROTATION PARAMETERS
 AT THE ESOC PROCESSING CENTRE FOR IGS

 J.M.Dow, J.Feltens, T.Martin-Mur, C.Garcia-Martinez

 Description of analysis for period 1993 January 23 - February 06
                            (last day of week 0680, weeks 0681 and 0682)
 1. SOFTWARE USED:   GPSOBS/BAHN-Version 5

 2. MODELS USED AND PARAMETERS ESTIMATED/FIXED:

  For a description of models and parameters used ==> see IGS - Mail  51
  For updates of the models and parameters used   ==> see IGS - Mail 114 and
                                                      see IGS - Rep. 224

 3. REMARKS: We have re-computed the weeks 0681 and 0682 plus day 023, which is
             the last day of week  0680. This re-evaluation of the last week of
             January and the first week of  February has been done according to
             decisions at the IGS workshop in Berne in March this year.  As re-
             commended in Berne,coordinate set SSC(IERS) 93 C 02 has been used.
             These coordinates are referred to epoch 1993.06, which corresponds
             to 22 January. It was also agreed in Berne, that the station velo-
             cities should be set to zero for the evaluation of this two weeks.
                  The evaluation  has been  performed  with our new  evaluation
             scheme as described in IGS report 224.
                  On 28 January (day 028),  SV-32's PRN number has been changed
             from PRN#32 to PRN#01 sometimes between UTC 20:55  and  UTC 21:20.
             In our computations this has  been handled  by treating PRN#32 and
             PRN#01 as two  independent satellites.  So our orbit files of days
             028 and  (because of the 12 hour overlap)  also 029  contain  both
             32 and 01. We recommend to use the orbit of  32  until day 028  at
             UTC 21:00 and from there on  01  when using our orbit files.  This
             can also be seen in table 5, in which PRN#32 has  an orbital error
             of  22.4 meters  on day 029.  The  reason is,  that because of the
             overlap, observations have been taken  from day  028  UTC 12:00 to
             UTC 21:00. So  PRN#32  is bad  determined in  day 029 orbit  file.
                  Comparisons show,  that with  our new  evaluation scheme, the
             orbital offsets with respect  to the  other analysis  centers have
             reduced to 50% compared with our  old original orbits from routine
             IGS processing in January and February.
                  For this  two weeks we  provide our precise orbits in form of
             earth-fixed as well as in form of J2000 ephemeris.

 4. GROUND STATIONS: Boucher and Altamimi, SSC(IERS) 93 C 02 (epoch 1993.06),
                     31-MAR-1993
 ___________________________________________________________
 GPSweek|ALGO  HART  MADR  MCMU  SANT  USUD  YELL  |f |e |t
 0681-82| FAIR  KOKB  MASP  PAMA  TIDB  WETT       |i |s |o
    |DAY|  GOLD  FOUR  MATE  RCM2  TROM  YAR1      |x.|t.|t.
 ---|---|------------------------------------------|--|--|--
    |023| FFF   FFe   Fee   -e-   FFF   eFF   F    |12| 5|17
    |024| FFF   FFe   Fee   -ee   FFF   eFF   F    |12| 6|18
    |025| FFF   FFe   Fe-   -e-   FFF   eFF   F    |12| 4|16
    |026| FFF   FFe   Fee   ee-   FFF   eFF   F    |12| 6|18
    |027| FFF   FFe   Fee   -e-   FFF   eFF   F    |12| 5|17
    |028| FFF   FFe   Fee   ---   FFF   eFF   F    |12| 4|16
    |029| FFF   FFe   Fee   -ee   FFF   eFF   F    |12| 6|18
    |030| FFF   FFe   Fee   eee   FFF   eFF   F    |12| 7|19
    |031| FFF   FFe   Fee   eee   FFF   eFF   -    |11| 7|18
    |032| FFF   FFe   Fee   eee   FFF   eFF   F    |12| 7|19
    |033| F-F   FFe   Fee   eee   FFF   eFF   F    |11| 7|18
    |034| FFF   F-e   Fee   -ee   F-F   eFF   F    |10| 6|16
    |035| FFF   F-e   -ee   eee   --F   eFF   F    | 8| 7|15
    |036| FFF   F-e   Fee   -ee   FF-   eFF   F    |10| 6|16
    |037| FFF   F-e   Fee   -ee   FFF   eFF   F    |11| 6|17

    with: "F" ... coordinates of ground station kept fixed,
          "e" ... coordinates of ground station estimated,
          "-" ... ground station not included on that day.

 5. ORBIT FIT MINUS EXTRAPOLATION FROM PREVIOUS DAY, RMS IN <METER>

  \DAY|  024   025   026   027   028   029   030
   \  |
    \ |
  SAT\|
  ----|-------------------------------------------
   02 |  3.5   2.3   1.1   1.8   1.0   1.8   1.4
   03 |  0.4   1.0   0.8   0.7   0.5   1.0   0.5
   11 |  3.5   1.4   1.5   1.2   0.6   1.2   0.8
   12 |  1.1   1.3   1.5   1.1   0.7   1.4   0.9
   13 |  2.0   1.4   1.7   1.4   1.0   2.0   0.5
   14 |  1.1   0.6   1.1   1.8   0.8   0.9   0.6
   15 |  1.4   2.4   2.5   0.9   2.0   1.4   1.4
   16 |  0.9   2.2   0.6   1.4   0.7   2.7   1.9
   17 |  1.1   0.8   1.0   1.7   0.8   1.4   0.8
   18 |  0.5   0.7   0.7   1.0   0.8   0.6   0.6
   19 |  2.1   1.9   1.1   1.3   2.1   1.6   2.7
   20 |  1.1   1.5   2.0   1.0   1.9   2.4   2.0
   21 |  1.7   2.1   1.1   1.7   2.2   1.5   0.8
   23 |  1.1   0.9   0.5   0.7   1.7   1.0   1.3
   24 |  1.7   1.8   1.1   2.1   0.9   1.9   1.1
   25 |  1.8   2.4   1.5   1.2   0.7   3.4   1.9
   26 |  0.6   0.7   1.3   2.7   1.0   3.8   0.9
   27 |  1.1   1.6   1.4   0.8   0.9   1.3   1.5
   28 |  2.3   1.2   1.1   1.0   0.7   2.6   0.8
   29 |  1.4   0.5   1.0   1.3   1.2   0.9   1.1
   32 |  0.8   1.0   2.5   3.5   1.0  22.4   0.0
   01 |  0.0   0.0   0.0   0.0   0.0   2.1   1.9

    ORBIT FIT MINUS EXTRAPOLATION FROM PREVIOUS DAY, RMS IN <METER>
                                                               CONTINUED
  \DAY|  031   032   033   034   035   036   037
   \  |
    \ |
  SAT\|
  ----|-------------------------------------------
   02 |  2.5   2.7   4.0   4.6   3.5   3.9   1.5
   03 |  0.9   0.9   2.1   1.4   0.6   1.2   0.8
   11 |  0.9   1.2   3.1   1.9   2.8   3.6   5.0
   12 |  0.5   4.6   1.6   1.6   0.7   2.4   1.6
   13 |  1.5   1.3   2.3   1.9   1.2   1.7   0.9
   14 |  1.4   0.9   2.8   2.9   1.4   3.6   1.6
   15 |  1.3   1.4   6.1   0.9   1.3   4.5   1.5
   16 |  0.7   1.3   3.5   2.5   0.5   1.2   2.1
   17 |  0.8   1.2   1.5   1.5   2.7   1.2   3.5
   18 |  1.0   1.0   2.2   2.0   2.7   0.7   1.5
   19 |  1.4   2.1   1.3   1.3   2.0   1.6   0.5
   20 |  1.2   3.8   3.3   2.4   1.2   3.0   2.7
   21 |  2.2   0.8   3.5   2.1   1.7   6.1   9.9
   23 |  0.9   0.6   3.3   2.4   2.9   1.6   7.9
   24 |  1.2   1.5   4.0   1.1   1.9   1.3   3.0
   25 |  2.4   2.0   3.9   2.0   1.7   0.8   2.6
   26 |  1.4   1.4   3.1   2.2   0.6   2.9   2.0
   27 |  1.1   1.1   1.7   1.9   1.8   1.4   2.0
   28 |  2.8   1.0   4.7   1.9   1.7   3.2   0.9
   29 |  0.6   1.3   2.0   1.6   4.0   1.3   1.5
   32 |  0.0   0.0   0.0   0.0   0.0   0.0   0.0
   01 |  2.1   0.9   1.5   3.2   2.4   1.0   2.2

 6. PRODUCTS GENERATED:

  The following products are generated and stored at AIUB
                                                   <ASTRONOMY.IGSCOMP>:

  ESA06806.EPH      - Precise GPS orbits, earth    fixed, for day 023
  ESA06806.EPHJ2000 - Precise GPS orbits, inertial fixed, for day 023
  ESA0681*.EPH      - Precise GPS orbits, earth    fixed, for week 0681
  ESA0681*.EPHJ2000 - Precise GPS orbits, inertial fixed, for week 0681
  ESA0682*.EPH      - Precise GPS orbits, earth    fixed, for week 0682
  ESA0682*.EPHJ2000 - Precise GPS orbits, inertial fixed, for week 0682
                      *=0 for Sunday,..., 6 for Saturday
  ESAJAN93.ERP - Earth rotation results for day 023 and weeks 0681 and
                                                0682 (includung DTU1R)
  ESAJAN93.SUM - This summary file

 End of Message

 ******************************************************************************

 ==============================================================================
 ESA/ESOC Earth Rotation Parameters for Week of 23 Jan - 06 Feb 1993
 ==============================================================================
 Field Contents (Value of 0 indicates parameter not available)
   1   MJD of the measurement
   2   x of the pole (")
   3   y of the pole (")
   4   d(UT1R-TAI)/dt (msec/day)
   5   uncertainty on x (")
   6   uncertainty on y (")
   7   uncertainty on d(UT1R-TAI)/dt (msec/day)
   8   rms residual of the least squares solution providing the EOP
   9   correlation coefficient : x, y
  10   correlation coefficient : x, DUT1R
  11   correlation coefficient : y, DUT1R
  12   number of contributing stations
  13   number of contributing satellites
  14   number of passes
  15   time span covered by the observations used (h)

 ESOC ERP TABLE                                          (1993 Jan 23 - Feb 06)
   MJD       X        Y     d(UT1R-TAI)XSIG    YSIG  DUT1SIG RMS  XYC  XUC  YUC
  STA SAT PASS TSP
             "        "      msec/day   "       "    msec/day
                h
  49010.5  0.21230  0.29837 -2.27560 0.00015 0.00017 0.02470 0.0 0.00 0.00 0.00
   17  21   0  48
  49011.5  0.21275  0.29631 -2.20150 0.00017 0.00018 0.03000 0.0 0.00 0.00 0.00
   18  21   0  48
  49012.5  0.21346  0.29505 -2.61740 0.00018 0.00019 0.02980 0.0 0.00 0.00 0.00
   16  21   0  48
  49013.5  0.21137  0.29284 -2.49950 0.00016 0.00020 0.02930 0.0 0.00 0.00 0.00
   18  21   0  48
  49014.5  0.21238  0.29052 -2.62820 0.00017 0.00019 0.02910 0.0 0.00 0.00 0.00
   17  21   0  48
  49015.5  0.21205  0.28799 -2.74810 0.00016 0.00020 0.03050 0.0 0.00 0.00 0.00
   16  21   0  48
  49016.5  0.21027  0.28455 -2.43720 0.00020 0.00023 0.03840 0.0 0.00 0.00 0.00
   18  21   0  48
  49017.5  0.20978  0.28252 -2.48990 0.00020 0.00019 0.03520 0.0 0.00 0.00 0.00
   19  21   0  48
  49018.5  0.20746  0.27966 -2.51580 0.00021 0.00021 0.03490 0.0 0.00 0.00 0.00
   18  21   0  48
  49019.5  0.20683  0.27641 -2.36750 0.00026 0.00023 0.03540 0.0 0.00 0.00 0.00
   19  21   0  48
  49020.5  0.20516  0.27361 -2.29600 0.00026 0.00029 0.04170 0.0 0.00 0.00 0.00
   18  21   0  48
  49021.5  0.20583  0.27081 -2.44810 0.00029 0.00027 0.03660 0.0 0.00 0.00 0.00
   16  21   0  48
  49022.5  0.20600  0.26913 -2.39330 0.00032 0.00032 0.04340 0.0 0.00 0.00 0.00
   15  21   0  48
  49023.5  0.20520  0.26804 -2.62930 0.00031 0.00028 0.04500 0.0 0.00 0.00 0.00
   16  21   0  48
  49024.5  0.20564  0.26315 -2.70580 0.00027 0.00028 0.03580 0.0 0.00 0.00 0.00
   17  21   0  48
 END ERP FILE
 ==============================================================================