The update of the coastal topo-bathymetric DEM of the Gironde estuary - downstream with a resolution of 0.0002° (~ 20 m) was carried out in the third phase of the HOMONIM project. This DEM covers the downstream part of the Gironde estuary, from Pauillac to its mouth. It is complementary to the DEM covering the upstream estuary. The DEM is intended to be implemented in hydrodynamic models in order to produce forecasts as accurate as possible of water heights and sea states at the coast to improve the relevance of the Wave-Submergence Vigilance. This product is available with either the Lowest Astronomic Tide (LAT) or the Mean Sea Level (MSL) as a vertical reference.

The update of the coastal topo-bathymetric DEM of the Pertuis charentais at a resolution of 0.0002° (~ 20 m) was carried out in the third phase of the HOMONIM project. The DEM extends from the terrestrial domain to about 60 meters depth over all the pertuis (pertuis Breton, pertuis d’Antioche and pertuis of Maumusson). The DEM is intended to be implemented in hydrodynamic models in order to produce forecasts as accurate as possible of water heights and sea states at the coast to improve the relevance of the Wave-Submergence Vigilance. This product is available with either the Lowest Astronomic Tide (LAT) or the Mean Sea Level (MSL) as a vertical reference.

Litto3D provides 3D, continuous sea-land description of French coastal areas. Data is acquired by airborne topo-bathymetric LiDARs. Litto3D products come in 3D point clouds and digital terrain models formats. The product "Litto3D - Nouvelle-Aquitaine 2020-2022" covers the geographical area from the Sèvre Niortaise to the Spanish border.

The coastal topo- bathymetric DEM for the coasts of Morbihan with a resolution of 0.0002° (~ 20 m) was prepared as part of the TANDEM project (Programme Investissements d'Avenir, ANR-11-RSNR-00023-01). It covers the French administrative department of Morbihan and part of Loire-Atlantique. This DEM runs from the Gâvres peninsula in the north west to La Baule in the south east and covers the Gulf of Morbihan, the Quiberon bay and peninsula, Houat, Hoëdic and Belle-Ile islands and the Vilaine estuary. The DEM is designed to be implemented in the hydrodynamic models of the TANDEM project in order to estimate the coastal effects of tsunamis for the Atlantic and English Channel, where French nuclear power plants have been installed for about 30 years. This product is available with the Lowest Astronomic Tide (LAT) or the Mean Sea Level (MSL) as a vertical datum.

Litto3D is a unique and continuous land-sea database which can provide 3D models of the shape and location of French coastal terrain. A line separates sea and land data acquisition zones, and the associated survey readings obtained using bathymetric lidar technologies or multibeam echosounders for sea readings and airborne lidar topographical surveys for land readings, with 300 m overlap. Litto3D digital models are available in two formats: a set of 3D points and a qualified terrain mesh.

Litto3D Marine Part is an intermediate product of the Litto3D product containing only marine data.Litto3D is a unique and continuous land-sea database which can provide 3D models of the shape and location of French coastal terrain. A line separates sea and land data acquisition zones, and the associated survey readings obtained using bathymetric lidar technologies or multibeam echosounders for sea readings and airborne lidar topographical surveys for land readings, with 300 m overlap. Litto3D digital models are available in two formats: a set of 3D points and a qualified terrain mesh.

Bathymetric datasets are an extraction of surveys belonging to the Shom public database. For depth up to 50m, the vertical precision of soundings varies from 30cm to 1m and the horizontal precision varies from 1 to 20m. In deep ocean, the vertical precision is mainly around 1 or 2% of the bottom depth. It is sometimes more, it depends on the technology used. The data are referenced to ZH which is assimilated to LAT. Data are corrected for sound velocity variations.

The bathymetric DEM for the coasts of Guadeloupe and Martinique with a resolution of 0.001° (~ 100 m) was prepared as part of the HOMONIM project. The DEM covers some of the Lesser Antilles islands, from Montserrat in the north to Sainte-Lucie in the south. The model ranges off-shore to a depth of 5800 m. The DEM is designed to be used in hydrodynamic models in order to produce high-precision forecasts for coastal water levels and sea conditions and therefore improve the pertinence of the Waves-Submersion monitoring programme.

The coastal topobathymetric DEM of Ré Island's surroundings, with a resolution of 0.00005° (~5 meters), was created by Shom as part of the HOMONIM-3 project. It covers the coast of the municipalities of Ars-en-Ré and Saint-Clément-des-Baleines, extending offshore to a depth of about 20 meters, to the west of the Phare des Baleines lighthouse. This DEM is designed for use in hydrodynamic models to enhance the modeling of coastal processes, particularly forecasting submersion risk. The product complements the coastal topobathymetric DEM of the Pertuis-Charentais, with a resolution of 0.0002° (~20 meters), and the bathymetric DEM of the Atlantic coast, with a resolution of 0.001° (~100 meters). It is available in the vertical reference of the Lowest Astronomical Tide (LAT) or the Mean Sea Level (MSL).

The bathymetric DEM for the coasts of Guadeloupe and Martinique with a resolution of 0.001° (~ 100 m) was prepared as part of the HOMONIM project. The DEM covers some of the Lesser Antilles islands, from Anguilla in the north to Saba in the south. The model ranges off-shore to a depth of 3275 m. The DEM is designed to be used in hydrodynamic models in order to produce high-precision forecasts for coastal water levels and sea conditions and therefore improve the pertinence of the Waves-Submersion monitoring programme.