Subject: [IGSMAIL-2584] NTUS data issues
From: Boudewijn Ambrosius & Danny van Loon (DEOS/DUT)
Date: Wed, 17 Nov 1999 15:13:55 PST

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IGS Electronic Mail      Wed Nov 17 15:13:55 PST 1999      Message Number 2584
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Author: Boudewijn Ambrosius & Danny van Loon (DEOS/DUT)
Subject: NTUS data issues

The return into service of NTUS (Singapore) as announced in IGS mail # 2568
has not been as smoothly as anticipated. Basically there are two issues:

1. As soon as the data started flowing, Jim Ray pointed out to us that the
   current download and rinexing procedure is inconsistent with the 
   recommendations described in IGS mail # 2320 for ACT technology receivers.
   As a result the C1 observable is not available in the Rinex files
   distributed since day 301. Only the L1, P1, L2 and P2 data are included.
   Apparently this may lead to unwanted biases when these data are mixed with
   data from the older receiver types. To correct this situation we will
   adjust the download and rinexing procedures as soon as possible in order
   to comply with the recommendations of IGS mail # 2320. However, this may
   take some time, since we do not have direct access to the station. We
   aplogize for not having noticed the importance of this issue before we
   re-activated the station. We are grateful to Jim Ray for bringing this
   to our attention. As soon as the new procedure goes into effect we will
   distribute another announcement.

2. Due to operational problems with the PC controlling the receiver download
   and internet upload tasks, the data flow since the resumption of the
   operations has been somewhat erratic. As a result, several days of data
   have been lost and part of the time the data was submitted with 1 or 2 days
   latency. We are in contact with local staff at NTUS to analyze these problems
   and to try to correct them.

We apologize for the inconvenience and we hope that NTUS will soon return as
a useful and reliable station. 

Boudewijn and Danny   

[Mailed From: Boudewijn Ambrosius <[email-masked]>]