The constellation of Pléiades satellites provides images that ideally combine wide coverage, high resolution (50 cm) and high update frequency: any point on the national territory is flown over every three to four days, with a resolution of 70 cm . IGN ensures the ortho-rectification of the images, to constitute "satellite orthos". The vectorization of the coastline from satellite images of the coastline of 2014 was carried out by CEREMA on behalf of DREAL Occitanie. The coastline here corresponds to the middle of the run-up (); smoothing was carried out to obtain the final layout. The work carried out on a test zone made it possible to assess a fine level of precision, of the order of one meter. () The run-up corresponds to the trickle of water rising on the instantaneous foreshore following the last wave. The return jet corresponds to the downward stream of water (back-wash). These two uphill and downhill movements define the swash, also called the ripple.
