GAVDOS Project
Chrisoskalitisa site (CRS1) contains a continuously operating GPS/GLONASS station located at the small fishing port of Stavros, Agios Nikolaos, Chrisoskalitisa, West Crete. The receiver was installed on 7 March 2008. It will also be collocated with a tide gauge (bottom pressure). Data will be downloaded via Hellasat communication link.
A connection to send and receive data from the Theophilos site in Gavdos has been established via the Hellasat communication satellite on 10 October 2007.
A new GPS/GLONASS station, collocated with the radar OTT tide gauge at the Karave harbor, Gavdos was installed on 30 August, 2007. The receiver is a LEICA GRX1200PRO (serial No. 352843) with an antenna LEIAX1202GG. The name of this station is GVD6.
At KARAVE site the Kalesto radar tide gauge was installed on 27 July 2007. This station, named KRV2, has been operational as of that date.
On 22 June 2007, the GPRS Vodafon link with static IP address at the GVD0 site (DOMES # 12618M001) has been established with the Operations Control Center at TUC. The GPS data from the Leica RS 500 are downloaded every hour. Also, the Aqutrack sea level data at Krave and the meteorological data at Theophilos are accessed in real time from TUC.
The UHF-link from the Operations Control Station (Chania) and Gavdos has been re-established as of 6 April 2006. The communication link was hit by lightning. Communication cables were burned down at SELLI relay station in Omalos, Crete.
On Tuesday 21 February, 2006, a new DORIS 3.0 beacon (S/N: 281931) along with its VAISALA meteorological station (s/n: 281907) has been set up again at Theophilos site, Gavdos. As of 10 April, 2006 the beacon transmits on satellite prediction mode.
In the beginning of GPS week No.1294 (25 Oct 2004), the new permanent station TUC2 was included in the EUREF Permanent Network. (DOMEs No: 12617M003). The complete site log can be retrieved from the EUREF permanent network Central Bureau: ftp://ftp.epncb.oma.be/ The daily and hourly data of TUC2 are available at the ASI EPN.
Ground observations and altimetry comparisons over cycles 70 to 90, indicate that a preliminary estimate of the absolute measurement bias for the Jason-1 altimeter is 144.7 � 15 mm. Comparison of Jason-1 microwave 15 radiometer data from cycles 37 and 62, with locally collected water vapor radiometer and solar spectrometer observations indicate a 1�2 mm agreement.
The Science Working Team (SWT) meeting for Jason-1 took place at St Peterburg, Florida, USA, 4-6 November 2004. Please visit aviso.oceanobs.com for updates.
The 36-month Co-ordination Meeting of GAVDOS took place at the Geodesy and Geodynamics Lab, Institute of Geodesy and Photogrammetry, ETH Hoenggerberg, Zurich, Monday 29 November 2004.
TUC visited Gavdos from 10-12 Jan 2005 for data downloading and instrument inspection. No construction works have taken place at the KARAVE jetty. The instruments are working properly.
Levelling survey was carried out by TUC to all bench marks from KARAVE to THEOPHILOS on 20 October 2004. The survey took place before the instrument removal and before jetty construction started.
Because of the present construction works, the acoustic and pressure tide gauges and some of the ocean sensors have been removed as of mid October 2004. The GVD5 (Ashtech Receiver) still operational.
The construction of the new jetty at Karave has started in October 2004. The space in front of the existing dock will be filled in with construction material (i.e., concrete blocks) and extended to the sea. The tide gauges should be removed. In that way we have to stop measuring sea level for a couple of months to facilitate construction.
SRISG and TUC visited Gavdos during 8-21 August 2004. Data had been downloaded. GPS measurements were carried out for GVD03 (cross-over point) by the SRISG. Solar panels were installed on DIAS to provide power for the transponder.
Ground observations and altimeter comparisons over cycles 70 to 77 indicate that a preliminary mean estimate of the absolute measurement bias for Jason-1 sea surface heights is 134 mm +/- 20 mm. Comparison of Jason Microwave Radiometer data with locally Water Vapour Radiometer and Solar Spectrometer observations indicate a 1-2mm agreement for cycles 37 and 62.
13 July 2004. The receiver Leica SR520 (AUTH) at GVD0 was replaced with the Leica RS500 (TUC).
11 June 2004. The EUMETSAT Antenna at Karave was removed and brought to TUC for testing because it was not operational. 17 June 2004. It was tested in Chania. It was inundated with salt, but cleaned thoroughly. Now ready to be reconnected in the next field trip. 12-13 July 2004. The antenna was put back and connected to Vitel datalogger.
TUC2: The GPS permanent station on a concrete pillar, next to the laser pad at the TUC campus, is operational as of 18 June 2004.
TUC team (Achilles, Akis, George and Kiryll) carried out a field trip in Gavdos. Second levelling and data downloads were performed.
Peter Pesec and Walter Hausleitner from SRISG have visited Gavdos to inspect the transponder and make measurements at sea level for Jason and Envisat.
New Gavdos site project started.
