HR: 0800h
AN: G51A-0146    [Abstracts]
TI: Monitoring Sea Level At L'Estartit, Spain
AU: * Martinez-Benjamin, J
EM: jj.benjamin@upc.edu
AF: Technical University of Catalonia, Dpt. Geotechnical Engineering and Geosciences Avda. Doctor Maranon, 44, Barcelona, 08028, Spain
AU: Ortiz Castellon, M
EM: miquel_angel.ortiz@icc.cat
AF: Cartographic Institute of Catalonia, Parc de Montjuic, Barcelona, 08038, Spain
AU: Martinez-Garcia, M
EM: marina@fa.upc.edu
AF: Technical University of Catalonia, Dpt. Geotechnical Engineering and Geosciences Avda. Doctor Maranon, 44, Barcelona, 08028, Spain
AU: Talaya, J
EM: julia.talaya@icc.cat
AF: Cartographic Institute of Catalonia, Parc de Montjuic, Barcelona, 08038, Spain
AU: Rodriguez Velasco, G
EM: geos@mat.ucm.es
AF: Universidad Complutense de Madrid, Plaza Ciencias, 3, Madrid, 28040, Spain
AU: Perez, B
EM: bego@puertos.es
AF: Puertos del Estado, Avda. del Partenon, 10, Madrid, 28042, Spain
AB: Sea level is an environmental variable which is widely recognised as being important in many scientific disciplines as a control parameter for coastal dynamical processes or climate processes in the coupled atmosphere-ocean systems, as well as engineering applications. A major source of sea-level data are the national networks of coastal tide gauges, in Spain belonging to different institutions as the Instituto Geográfico Nacional (IGN), Puertos del Estado (PE), Instituto Hidrográfico de la Marina (IHM), Ports de la Generalitat, etc. Three Begur Cape experiences on radar altimeter calibration and marine geoid mapping made on 1999, 2000 and 2002 are overviewed. The marine geoid has been used to relate the coastal tide gauge data from l'Estartit harbour to off-shore altimetric data. The necessity to validate and calibrate the satellite's altimeter due to increasing needs in accuracy and long term integrity implies establishing calibration sites with enhanced ground based methods for sea level monitoring. A technical Spanish contribution to the calibration experience has been the design of GPS buoys and GPS catamaran taking in account the University of Colorado at Boulder and Senetosa/Capraia designs. Altimeter calibration is essential to obtain an absolute measure of sea level, as are knowing the instrument's drifts and bias. Specially designed tidegauges are necessary to improve the quality of altimetric data, preferably near the satellite track. Further, due to systematic differences a month instruments onboard different satellites, several in-situ calibrations are essentials to tie their systematic differences. L'Estartit tide gauge is a classical floating tide gauge set up in l'Estartit harbour (NE Spain) in 1990. It provides good quality information about the changes in the sea heights at centimetre level, that is the magnitude of the common tides in theMediterranean. In the framework of a Spanish Space Project, ref:ESP2001- 4534-PE, the instrumentation of sea level measurements as been improved by providing this site with a radar tide gauge and with a continuous GPS station nearby. This will have a significant incidence in the satellite altimeter calibration activities. The radar tide gauge with data recorder and transmitter is a Datamar 3000C with 26 GHz frequency, 1mm resolution, 8º beam width incorporating a GPS receiver for automatic clock synchronization and a Thales Navigation Internet-Enabled GPS Continuous Geodetic Reference Station (iCGRS) with a choke ring antenna. It is intended that the overall system will constitute a CGPS Station of the ESEAS (European Sea Level) and TIGA (GPS Tide Gauge Benchmark Monitoring) networks. A Partenavia P-68 airborne LIDAR campaign carrying an Optech Lidar ALT-3025 has been made in June 2007 to test the potential of Lidar to connect sea level measurements from tide gauges at the coast with satellite (as Jason-1 or Envisat) altimetry measurements offshore. The calibrated airborne Lidar can then be used over ocean to detect the sea surface height. In consequence, the objective is to check that the coastal sea level can be observed with GPS buoys and may be Lidar campaigns for get detailed regional geoid and sea surface topography models for referencing satellite altimeter measurements.
DE: 1200 GEODESY AND GRAVITY
SC: Geodesy [G]
MN: 2007 Fall Meeting