From: George Preiss
Date: 10 JUL 1992 11:55:59 
Subject: [IGSMAIL-40] Antenna Heights TROM & NYAL

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IGS Electronic Mail       10-JUL-1992 19:13:12       Message Number 40
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                   THIS FILE CONTAINS 3 MESSAGES
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From:    George Preiss
Subject: Antenna Heights TROM & NYAL
         ---------------------------

Dated: 1126 UTC, Fri Jul 10 1992                      My reference:  E107/92

*** Please quote my reference in replies ***

ANTENNA HEIGHTS - TROMSO AND NY ALESUND

We confirm that the antenna height at TROM has not been changed. Something as
yet unidentified happened in the downloading and file transfer processing to
suddenly give a 0.000 metres height for day 175.

For NYAL, we confirm that the antenna height is 5.203 metres, and checked and
confirmed.

Regards
George Preiss


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From:    Chris Reigber
Subject: Analysis results from GFZ
         -------------------------

1. Analysis Center: GFZ/DLR
2. Solution Identifier: EPH(GFZ)92G01-DDD
                        ERP(GFZ)92G01-DDD
                        CLK(GFZ)92G01-DDD (only relative)
3. Software used: GEPARD4.0
4. Defintion of Terrestrial Reference Frame
   Origin: Nominally ITRF-90
   Orientation: Nominally ITRF-90
   Reference Epoch: 1992.352 (MJD 48750)
   Fixed set of stations: Y. Bock Solution (IGS Message No.35)
   ALGO, YELL, FAIR, KOKR, TROM, WEZ1, YAR1, USUD, NALL
5. Data used:
   - undifferenced pseudo ranges and carrier phases
   - 2-day arc solutions with one day overlap
6. Adjusted parameters:
   - State vector of all GPS satellites
   - Daily polar motion
   - Coordinate corrections for non-fixed stations
   - Troposheric zenith path delay 
   - Solar radiation scale and y-bias 
   - Ambiguities
   - ST and SV clock parameters of each observation epoch (the 
     maser-based clock at Fairbanks is taken as reference clock)

--------------------------------------------------------------------------

Identification of IGS product files submitted by GFZ:
(the naming convention is equal to IGS Message No.16)

      cccwwwwd.ttt

      with  ccc:  GFZ
            wwww: Gps week number (e.g. 0650)
            d:    Day of the week
            ttt:  File type
                  ERP: Earth Rotation Parameters
                  EPH: Precise Ephemerides
                  CLK: Satellite clocks (relative)

- GFZ06502.EPH
  ============

  The precise ephemerides contains GPS satellite state vectors
  as a function of time (every 5 minutes) in the ITRF90 
  coordinate system; their reference time is consistent with
  GPS time.  The ephemerides are given in the NGS sp3 format 
  which contains tabulated positions and velocities beginning
  at 0 h 0 m 0.0 sec each day. The ephemerides files are available
  at CDDIS, IGN and IfAG.

  First results for the quality of the calculated orbits are listed
  below. For the day 174 the overlap rms differences [cm] in radial, 
  cross- and along-track component are presented.

      SV   2   3  11  12  13  14  15  16  17  18  19  20  21  23  24  25  28
  --------------------------------------------------------------------------      
  radial  63  26  65  90  17  20  38  30  18  53  35  17  26  23  32  40  92  
  cross   52  67  94  61  43  37  36  36  55  58  51  56  52  57  32  95  48
  along  129  80 194 115  60  64  72  70  51  71  67  34  53  51  96  86 155
  --------------------------------------------------------------------------

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From:     Dennis McCarthy
Subject:  Preliminary look at GPS Earth orientation
          -----------------------------------------

Date:     10 July 1992


An updated look at Earth orientation data submitted to the IERS
follows.  Units are milliseconds of arc for x and y, and
milliseconds of time for UT1-UTC.


Contributor Data Span Points       Mean          Standard Deviation
                                (NEOS-GPS)  
                              x     y   UT1-UTC   x     y   UT1-UTC
U. of Texas  48794.5     7  -0.55  0.34          0.43  1.85  
             -48800.5

Scripps      48781.0    19  -0.09  1.40          1.46  1.03
             -48799.0     

U. of Berne  48792.5     8   0.04  0.37  -1.51   2.03  1.77  0.14 
             -48800.5

JPL          48794.5     7   0.02 -0.04          0.66  1.72 
             -48800.5

Plots are available by FAX to anyone interested.

Regards,

Dennis McCarthy
  dmc@maia.usno.navy.mil