The coastal topo-bathymetric DTM of the Arcachon basin and its surroundings at a resolution of 0.0002° (~ 20 m) was produced as part of the HOMONIM project. The DTM covers the coastline of a part of the Gironde department, from the Carcans and Hourtin ponds in the North, to the Cazaux and Sanguinet lakes in the South. It covers the entire Arcachon basin and extends offshore to about 40 m depth. The DTM is intended to be implemented in hydrodynamic models in order to produce accurate forecasts of water heights and sea states at the coast and to improve the French storm surge warning system.

Bathymetric datasets, collected after 2005, are controlled and qualified. They are mainly acquired with multi-beam echosounders.

Bathymetric datasets, collected between 1970 and 1990, are mainly acquired with single-beam echosounders. Quality controls and qualification, conducted by the Shom, on these datasets are not exhaustive. Datasets may present significant uncertainties and errors may remain.

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. The vertical reference for this product is the Lowest Astronomical Tide (LAT).

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.

The update of the coastal topo-bathymetric DEM of the Gironde estuary - upstream with a resolution of 0.0002° (~ 20 m) was carried out in the third phase of the HOMONIM project. This DEM covers the upstream part of the Gironde estuary, from Pauillac to Bordeaux on the Garonne and to Libourne on the Dordogne. It is complementary to the DEM covering the downstream estuary (between Pauillac and the mouth of the Gironde). 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.

Lidar marine part 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.

For more than 200 years, Shom has maintained a bathymetric knowledge base enriched by surveys and campaigns over time. They are composed of point clouds which have a density higher than those shown on nautical charts. Datasets are stored in the Shom Bathymetric Database (BDBS) which is a source to describe seabed reliefs. These data are useful for many applications as oceanographic modeling or seabed exploitations. The bathymetric datasets have been granted a distribution agreement. Data are not modeled. This modeling is left to the initiative of the customers. In other terms, they are point clouds data on the field, treated to the hydrographic standards in force at the time of their acquisition and validated. The product is composed of bathymetric datasets which cover the entire French Exclusive Economic Zone (EEZ) as well as international waters. The cover and its cutting are available on the Shom portals (data.shom.fr). Data positions are provided in geographic coordinates reported to the World Reference Geodetic System WGS84. They are vertically referenced to the zero of the soundings reduction which is usually associated to the hydrographic Chart Datum of the corresponding area. For depths up to 50m, the data vertical accuracy varies from 30cm to 1m and the planimetric accuracy varies from 1 to 20m. Beyond, in deep seas, the vertical accuracy is mainly of the order of 1 to 2% of the bottom depth. Sometimes, it is higher depending on the technology used.

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.

The bathymetric DEM of Tahiti and Moorea with a resolution of 0.001° (~ 100 m) was produced by the Shom for Météo-France (Inter-regional Direction in French Polynesia). This DEM covers a 10 km radius around the islands of Tahiti and Moorea in order to meet the need for marine submersions modelling in French Polynesia. This product is available at different vertical references, either the lowest astronomical tide (LAT) or the mean sea level (MSL).