On The Application Of A Two-Dimension Spatio-Temporal Cross-Correlation Method To Inverse Coastal Bathymetry From Waves Using A Satellite-Based Video Sequence

This article shows the capacity a two-dimension spatio-temporal cross-correlation method for estimating wave velocity and inverse bathymetry. It is presented and applied to the image sequence of the submetric Pleiades satellite mission (Airbus/CNES) which allows to acquire a sequence of images at a regional scale (100 km(2)). A good agreement is found with the bathymetry obtained during the COMBI2017 Capbreton experiment (correlation of 0.8, RMSE=1.4 m). A saturation of the depth estimate is found for depths greater than 35 m, mainly in a deep canyon just off the coast. The results show that the accuracy increases with the number of images in the sequence. A new possibility of high-frequency signal reconstruction offered by the spatio-temporal correlation method is investigated, using dense spatial and sparse temporal data. Despite their noisy nature, newly available time-updated satellite bathymetries can be used to understand coastal evolution at several scales and improve risk mitigation strategies through modelling.