Subject: [IGSMAIL-114] ESA/ESOC analysis results
From: Joachim Feltens
Date: 7 OCT 1992 17:58:32

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IGS Electronic Mail        7-OCT-1992 17:58:32       Message Number 114
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==============================================================================
                   THIS FILE CONTAINS  MESSAGES
==============================================================================

From:     Joachim Feltens
Subject:  ESA/ESOC analysis results
          -------------------------

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

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

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

Description of analysis for period 1992 September 20 - 26

 *******************************************************************************
 During the weekends  of days 263 to 265 (Sept. 19 - 21) and of  days 270 to 272
 (Sept. 26 - 28) anti-spoofing  has been switched on.  Nevertheless  data of all
 18 satellites has been  processed, and the  orbits of all  GPS-spacecrafts have
 been improved.
 *******************************************************************************

1. SOFTWARE USED:   GPSOBS/BAHN5

2. MODELS USED AND PARAMETERS ESTIMATED/FIXED

   For a description of models and  parameters we are using, see IGS-Mail 51. In
   The meantime the following changes  have been done  with  respect to that de-
   scription:
              - satellite clock drift excluded from the modeling (IGS-Mail 101),
              - evaluation of 30-hour arcs (IGS-Mail 108),
              - changes in the ground stations being used, in their coordinates,
                and in their status, i.e. being kept fixed or estimated (for the
                current configuration see the table under point 3 "GROUND STA-
                TIONS" in this note).

   Until now, in the  estimation process no a-priori  standard deviation values
   were given to the initial values of  the estimated parameters. Starting with
   week 14,the following constraints were given a-priori to the estimated para-
   meters:

      Satellite     position:                   +- 100 <m>
                    velocity:                   +-  10 <cm/sec>
                    ROCK4(2) scaling factor:    +-   5 % deviation from value 1
                    Y-bias:                     +-   0.2E-05 <Newton>

      ERPs          xp:                         +-   5 <masec>
                    yp:                         +-   5 <masec>

      Station       position:                   +-  20 <cm>
                    atm. zenith delay           +-  20 <cm>

3. GROUND STATIONS (if being estimated, one position (X,Y,Z) every day):

      The following table gives an overview over the ground stations,  that have
      been included into the GPS-data processing at ESOC. Except where otherwise
      noted ("remarks"), corrections are taken from IGS Mail No. 90  -  IGS site
      information and coordinates,updated version of IERS/IGS Tables in IGS Mail
      No. 65  -  (Boucher and Altamimi).
      __________________________________________________________________________
                          |             |    |    GPS WEEK 663     |
                          |             |    | 2  2  2  2  2  2  2 |
                          |             |    | 6  6  6  6  6  6  7 |
              SITE        |   COUNTRY   |CODE| 4  5  6  7  8  9  0 |  REMARKS
      --------------------|-------------|----|---------------------|------------
        Algonquin         | Canada      |ALGO| F  F  F  F  F  F  F |
        CANB/Tidbinbilla  | Australia   |TIDB| e  e  e  e  e  e  e |
        Penticton         | Canada      |DRAO| F  F  F  F  F  F  F |
        Fairbanks         | U.S.A/Alaska|FAIR| F  F  F  F  F  F  F |
        Goldstone         | U.S.A.      |GOLD| F  F  F  F  F  F  F |
        Hartebeesthoek    | South Africa|HART| F  F  F  F  F  F  F |
        Herstmonceux      | U.K.        |HERS| ----- F  F  F  F  F |
        Kokee Park        | U.S.A/Hawaii|KOKB| --------------------|
        Kourou      (ESA) | French Guyan|KOUR| ------------------- | own estim.
        Madrid            | Spain       |MADR| F ------ F  F  F  F |
        Maspalomas  (ESA) | Spain/Can.Is|MASP| e  e  e  e  e  e  e |
        Matera            | Italy       |MATE| F --- F  F  F  F  F |
        McMurdo           | Antarctica  |MCMU| e  e  e  e  e  e  e |
        Metsahovi         | Finland     |METS| F  F  F  F  F  F  F |
        Ny Alesund/Spitzb.| Norway      |NYAL| ----- e  e  e  e  e |
        Onsala            | Sweden      |ONSA| F  F  F  F  F  F  F |
        Pamate/Tahiti     | France      |PAMA| -- e  e  e --- e  e |
        Santiago          | Chile       |SANT| F  F  F  F  F ----- |
        St.John's, NF     | Canada      |STJO| e  e  e  e  e  e  e |
        Tai-Shi           | Taiwan      |TAIW| ----- e  e  e  e -- |
        Usuda             | Japan       |USUD| e  e  e  e  e  e  e |
        Wettzell          | Germany     |WETT| -- F  F  F --- F  F |
        Yaragadee         | Australia   |YAR1| -------- F  F  F  F |
        Yellowknife       | Canada      |YELL| F  F  F  F  F  F  F |

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

4. PRODUCTS GENERATED

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

   ESA0663*.EPH   - Precise GPS orbits, * = 0 for Sunday ,..., 6 for Saturday
   ESA06637.ERP   - Earth rotation results for week beginning 1992 September 20
   ESA06637.SUM   - The name of this text file

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

From:     Joachim Feltens
Subject:  kokee park
          ----------

SINCE SEPTEMBER 13 (DAY 257), WE'VE GOTTEN NO DATA FROM THE HAWAIIAN GROUND
STATION KOKEE PARK. ON LATE AFTERNOON OF SEPTEMBER 11 HURRICANE INIKI
SLAMMED INTO THE HAWAIIAN ISLAND KAUAI. AS FAR AS I KNOW, KOKEE PARK IS
LOCATED ON KAUAI. SO HAS KOKEE PARK PERHAPS SUFFERED THE SAME DESTINY
AS RICHMOND IN FLORIDA HAD SOME WEEKS AGO WITH HURRICANE ANDREW?

IGSMAIL: Yes, Kokee Park has suffered from hurrican Iniki but it seems they are
         only out of electricity (for the time being). The station and the 
         receiver have NOT been damaged!

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

From:     Tom Clark
Subject:  Concerning IGS Mail Archives
          ----------------------------

Several people have asked about archive copies of the IGS Mail messages.
Here at NASA/Goddard we have been maintaining two sets.

On  CDDIS.gsfc.nasa.gov , Carey Noll has been keeping the mail in individual
files in the directory    
                       GPS3:[IGSMAIL]

where the files are named like
                       IGSMESS.xxx

and where there is a index (one line per contribution) named
                       IGSMESS.INDEX

The second archive is on my  TOMCAT.gsfc.nasa.gov  host (which supports
anonymous ftp access beginning at the root /public directory) in the 
directory
                       /public/gps/igs

In that directory you will find the historical messages collected in
groups of ten and compressed with PKZIP in files named like
                       /public/gps/igs/igs-07x.zip

which contains messages numbered 070 thru 079. The total PKZIP compressed
size for messages 001 thru 110 is about 500 kbytes. In that directory you
will also find a file
                       /public/gps/igs/index

which is an ASCII mirror of the CDDIS IGSMESS.INDEX file. You will also
find files named like   igs.112   which are the current messages being
collected for the next .zip file.

Tom Clark

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

From:    IGSMAIL, Bern
Subject: No more IGSMAIL to FAX e-mail adresses

This will be the last IGSMAIL message which will be distributed to FAX
machines! This decision had to be taken due to budget restrictions. We hope
this is not to much of an inconvenience. But we would like to refer to the
possiblity of obtaining the messages by ANONYMOUS FTP from our account in the
directory
                       AFTP:[IGSMAIL]
 
where the files are named like
                       IGSMESS.xxx

and where there is a index (one line per contribution) named
                       IGSMESS.INDEX

and refer to the information given above in the message from Tom Clark.