[IGSREPORT-0650] Subject

[ESOC]

IGS Electronic Report    Fri Dec 10  6:34:16 PST 1993      Message Number 0650
******************************************************************************

Author: ESOC IGS-team
Subject: Subject: ESA07257.SUM

Subject: ESA07257.SUM

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

 Description of analysis for period 1993 Nov 28 - Dec 04
                                                        (week 0725)
 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. 224,277
 3. REMARKS:

  1. From this week we have started to estimate the clock bias of receivers
   and satellites. The values for the satellite clock bias every 15 minutes
   are now in our sp3 file. The reference is intended to be the average
   clock bias of the healthy GPS satellites, so in average our clock biases
   and the navigation message clock biases have to be the same. Clock biases
   are being estimated every 1 minute and we will archive the clock bias
   for the GPS satellites at this rate, so we can make them available to
   the IGS community if somebody is interested in having them. (We still
   have to agree on an IGS format for high rate clock biases.) We have made
   tests of point positioning using the orbits and clock biases every 15
   minutes and when point positioning is done independently for every epoch
   the repeatability is in the order of 1 metre for each coordinate, so
   we can say that the accuracy of our clock biases is better that 10
   nanoseconds. A last remark, our clock biases are not corrected for GPS
   satellite L1/L2 delay, so when they are used this correction does not
   need to be applied.

  2. Lack of observations for:
       PRN13 the whole week
       PRN03 on days 332 and 333
       PRN25 on day 336

  3.High residuals and modelling problems for satellite
       PRN09 on days 336 and 337.

 4. GROUND STATIONS: Boucher and Altamimi, IGS workshop Berne 24-27 March'93
                     IGS/IERS station coordinates in the ITRF91 at 1992.6
 _________________________________________________________________
 GPSweek|ALGO  GOLD  KOKB  MADR  MCMU  RCM5  TIDB  WETT  |f |e |t
 0725___| FAIR  HART  KOSG  MASP  PAMA  SANT  TROM  YAR1 |i |s |o
    |DAY|  FORT  KIRU  KOUR  MATE  PERT  TAIW  USUD  YELL|x.|t.|t.
 ---|---|------------------------------------------------|--|--|--
    |332| FFe   FFe   Fee   Fe-   -ee   eFe   FFe   FFF  |12|10|22
    |333| FFe   FFe   Fee   Fee   -ee   eFe   FFe   FFF  |12|11|23
    |334| FFe   FFe   Fee   Fee   -ee   eFe   FFe   FFF  |12|11|23
    |335| FFe   FFe   Fee   Fee   -ee   eFe   FFe   FFF  |12|11|23
    |336| FFe   FFe   Fee   Fee   eee   eFe   FFe   FFF  |12|12|24
    |337| FFe   FFe   Fee   Fee   eee   eFe   FFe   FFF  |12|12|24
    |338| FFe   FFe   Fee   Fee   eee   eFe   FFe   -FF  |11|12|23

    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 <CENTIMETER>

  \DAY|  332   333   334   335   336   337   338
   \  |
    \ |
  SAT\|
  ----|-------------------------------------------
   02 |   66    49    66    98    54    76    48
   03 |   99   195    38    46    49    26    61
   12 |   64    67    50    49    86    58    53
   13 |   75    42   115    79   124   130    41
   14 |   24    40    20    29    42    50    27
   15 |   38    97    63    63    86    84    40
   16 |   25    30    42    74    38    77    27
   17 |   41    86    43    33    42    29    41
   18 |   80    45    52    30    55    47    68
   19 |   75    77    66    65    81   138    81
   20 |   88    39    57    47    57    42    45
   21 |   30    25    36    39    58    35    47
   22 |   88   136   142   148    95   105   158
   23 |   19    98    74    19    44    35    72
   24 |   69    46    41    69    78    32    51
   25 |   56    56    73    52   208   179   122
   26 |   76    44    22    18    45    53   114
   27 |  127    73    75    72    71    72    79
   28 |   72    61    73    46    62    49    49
   01 |   29    56    41    52    68    52    54
   29 |  115    58    58    31    82    56    36
   31 |   48    54    53    56    53    68    46
   07 |   69    43    85   119    61    69   126
   09 |   73   101    98    48   196  1121   623
   05 |   56    50    48    72    88    54    70
   04 |   92    75   119   116   138    70   141

 6. PRODUCTS GENERATED:

  The following products are generated and stored in CDDIS at NASA/GSFC:

  ESA0725*.EPH - Precise GPS orbits and clocks, *= day of the week (0-6)
  ESA07257.ERP - Earth rotation results for week 0725 (including DUT1R)
  ESA07257.SUM - This summary file

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