An Improved Approach for Monitoring Intertidal Topography Using the Waterline Method

There is an increasing need for measuring the topography of intertidal environments in a regular manner. Spaceborne monitoring of intertidal environments is essentially performed using the waterline method. In this study we propose a new automatic approach for using the waterline method to derive intertidal Digital Elevation Models (DEMs). The changes include a faster, more efficient, and quasi-automatic detection and post-processing of waterlines. Using Sentinel-1 and Sentinel-2 images, DEMs were generated by this new waterline method approach for the Arcachon Bay and the Bay of Veys located both on the French Coast. The comparison of the generated DEMs with lidar observations showed an error of about 19–29 cm.