Subject: [IGSMAIL-2442] IGS site GRAZ, rearrangements-proposal
From: Peter Pesec
Date: Mon, 23 Aug 1999 0:07:10 PDT

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IGS Electronic Mail      Mon Aug 23  0:07:10 PDT 1999      Message Number 2442
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Author: Peter Pesec
Subject: IGS site GRAZ, rearrangements-proposal

At present the observatory Graz-Lustbuehel in Austria operates 3
receivers with different
dome-numbers and 4-char IDs:

11001M002: <GRAZ>, Turborogue SNR-8000 --> 30-sec sample, main IGS site
11001M003: <GRAA>, Trimble 4000SSI --> DGPS site, 1-sec sample, hourly
files
11001M004: <GRAB>, Ashtech Z-18 --> IGEX site, 1-sec sample rate, hourly
files optional.

All three receivers are working continuously, during the last month no
data gaps could be
detected for all receivers - in particular the Z-18 was working well, in
contrary to 
data gaps reported elsewhere.

First of all I would like to raise the general question wheather a
station
cluster which is centered to the mm-level can also be regarded as
equivalent by IGS and/or
EUREF - that means it makes no difference to use particular data from
<GRA?>, which makes
sense if one of the receivers is malfunctioning. In that case no action
is required for Graz,
we simply disseminate the appropriate data-files.

We see however problems if IGS and/or EUREF only acknowledge the
receiver situated above
the main point (presently a Turborogue). We are not in the position to
guarantee hourly
data from the Turborogue, the percentage of COM-errors is about 2, which
means that every
50th downloading leads to a blocking of the communication line, which is
not reliable for
24 downloadings per day. Moreover the well-known ionospheric problems
affect the Turborogue
efficiency.

One way out of this dilemma is to change receiver positions - i.e. to
place the Z-18 or
the 4000SSI on the main point and to operate the others on the auxilary
points. In that case
the installation of the Z-18 at the main pint would be the logical
promising continuation of the IGEX-project. Here we can deliver pure
GPS-Rinex-files, pure GLONASS-Rinex-files or
combined ones of any sample rate and of arbitrary length (hourly,
half-hourly, ..) as 1-sec
data are stored in the PC for about half a year. This statement is also
valid for the
Trimble 4000SSI.

I kindly ask the IGS- and EUREF-analysis centers to discuss this
question.

Best regards
Peter    

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Dr. Peter Pesec                     Tel : +43-316-467350
Space Research Institute,           Fax : +43-316-467356
Department Satellite Geodesy        Mail: [email-masked]
Austrian Academy of Sciences
Lustbuehelstrasse 46, A-8042 Graz
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[Mailed From: Peter Pesec <[email-masked]>]