Bathymetry Modelling from Altimeter-Based Gravity and Satellite Multispectral Images in the North Adriatic

Topography of the seafloor is an important parameter in almost all maritime related research. Traditional shipboard bathymetry methods are time and money consuming. Bathymetry LiDAR is optimal method for deriving depth of shallow sea areas but also quite expensive. Alternative methods for bathymetric mapping are low cost satellite remote sensing methods. Satellite altimetry opened the possibility to map topography of the seafloor on the global scale. However, these data have a coarse resolution and their quality decay in coastal areas. Satellite Derived Bathymetry SDB refers to methods to estimate the depth from multispectral satellite images and are widely used in shallow coastal sea areas. SDB is limited by the extinction depth up to which it is possible to retrieve bathymetric data. In this paper, digital bathymetry model of the study area in the North Adriatic is estimated combining data from altimeter-based gravity anomalies and satellite multispectral images. Depth is predicted using the Gravity Geologic Method and density contrast between seafloor and seawater is determined by control points composed of soundings from nautical chart. Bathymetry of shallow, coastal areas is enhanced by depth data derived from multispectral images using Satellite Derived Bathymetry methods. Model is validated against data from nautical charts. As compared to traditional survey methods, the model is time and cost-effective and has a high correlation with charted soundings.