Progress in the development of a method for constructing a Digital Elevation Model (DEM) of an inter-tidal zone using remote sensing and hydrodynamic modelling is described. The method allows the construction of an inter-tidal DEM over large areas relatively quickly as well as frequent subsequent monitoring of the DEM to detect changes, and is particularly suited to SAR satellite data because of the all-weather day-night capability of SAR. The resulting DEM may be used for the development of improved hydrodynamic models, and for studying sediment mass transport in the intertidal zone. ¿ American Geophysical Union 1995