1. Contribution of l’Estartit tide gauge to the altimeter calibrations: Technology upgrades and new instruments Marina Martinez Garcia 1,2, Juan Jose Martinez Benjamin 1, Miquel Angel Ortiz Castellon 3, Elena Tel 4, Maria-Jesús Garcia 4, Roman Leckzinsky 5 1 Technical University of Catalonia (UPC), Department of Geotechnical Engineering and Geosciences, Spain, marina@fa.upc.esmarina@fa.upc.es 2 Starlab Barcelona s.l., Spain, marina.martinez@starlab.esmarina.martinez@starlab.es 3 Cartographic Institute of Catalonia (ICC), Barcelona, Spain 4 Instituto Nacional Oceanográfico (IEO), Spain 5 Geónica Earth Sciences, Spain

2. 2007 Ocean Surface Topography Science Team Meeting Presentation L’Estartit gauge is a classical floating tide gauge set up in l’Estartit harbour (NE Spain) in 1990.

3. 2007 Ocean Surface Topography Science Team Meeting Foundation of measurement at l’Estartit  Measurement: Relative Sea Level (geodeic mark at the harbor) by means of a float in a stilling well.  From the physics to the data: 1.- The float is about 45cm diameter  large diameter to reduce errors in buoyancy due to friction of the gearing and small changes in the length of float wire. 2.- The wire is coiled round a drum on the end of the gauge and another drum contains the counter balance wire. 3.- The drum is geared to a slotted tape attached to a pen carriage which travels the chart during the rise and fall of the tide.

4. 2007 Ocean Surface Topography Science Team Meeting New devices and sensors at l’Estartit  Radar tide gauge Datamar 3000C (Water level microwave sensor WLPULS-62)  possible connection of additional hydrological, meteorological or environmental sensors.  Thales Navigation Internet-Enabled GPS Continuous Geodetic Reference Station (iCGRS) System  with a choke ring antenna are working in simultaneously to the old installation.