From: Boudewijn Ambrosius Message-Id: <200012012240.eB1MeMm50628@dutlru3.lr.tudelft.nl> Subject: [IGSMAIL-3120]: NTUS temporarily unavailable To: igsmail@igscb.jpl.nasa.gov Date: Fri, 1 Dec 2000 23:40:21 +0100 (MET) Sender: owner-igsmail Precedence: bulk ****************************************************************************** IGS Electronic Mail 01 Dec 14:40:24 PST 2000 Message Number 3120 ****************************************************************************** Author: Boudewijn Ambrosius & Danny van Loon (DEOS/DUT) Following up on IGS-mail #2931, we have to report that during the past 5 months, the data flow from NTUS (Singapore) has gradually become increasingly erratic, and finally came to a full stop on day 294. Due to the long distance, it was difficult to assess the problem. In October, Danny van Loon visited the station and tested alternative cables, antennas and locations. The problem could not be localized. Eventually we had the receiver returned to Delft and tested it in Kootwijk. Initially it seemed OK, but after a short while the same problems (frequent loss of lock) appeared. By chance, Danny found that the receiver (AOA SNR-12 ACT #229) worked well when he connected it to an external frequency source. So, the problem seems to be with the internal clock. Around the same time, two other AOA receivers broke down in Kootwijk (KOSG). Therefore, we will keep #229 at KOSG for the time being. Another unit has been shipped to AOA for repair and will be installed at NTUS asap. We are very embarrassed with the situation. Local support by Singapore staff has been excellent. However, the frequent mysterious break-downs of AOA equipment are difficult to diagnose at remote locations. We sincerely hope NTUS will be back on-line soon. We regret the inconvenience these problems may (have) cause(d). Boudewijn and Danny