CoAuthors

Frédéric Frappart (Laboratory for Studies in Geophysics and Spatial Oceanography - (LEGOS) , France); Vincent Marieu (Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), France); Alexandra Spodar (Laboratoire d’Océanologie et de Géosciences, France); Jean-Paul Parisot (Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), France); Benoit Laignel (Morphodynamique continentale et côtière (M2C), France); Imen Turki (Morphodynamique continentale et côtière (M2C), France)

Satellite radar altimetry was developed to measure ocean surface topography along the nadir track of the satellite. Near the coasts, data acquisition and processing suffers from several flaws. Major efforts are currently undertaken to extend the capabilities of satellite altimetry as close as possible to the coast. We present an investigation on the potential of radar altimetry to monitor sea level and along-track topography (at low-tide) of coastal lagoons. The case study site is the Bay of Arcachon located on the southwest coast of France which was flown over by the RA-2 radar altimetry mission onboard ENVISAT over the 2003-2012 period, and has been under the Altika radar altimetry mission onboard SARAL track since February 2013. The results obtained using ENVISAT and SARAL are validated against ancillary data (i.e. tide gauges records, LIDAR Topography) to estimate the accuracy of the measurements and to show its evolution between the Ku (frequency of 13.5 GHz used by ENVISAT RA-2) and the Ka (frequency of 35.5 GHz used by SARAL Altika) bands. An evaluation was undertaken as well for observations made by the Ku-band satellite mission CryoSat-2 (launched in April 2010) dedicated mainly to polar observations.