Extracting Water Depth from Landsat-8 Multispectral Satellite Imagery in Coastal Waters

Bathymetric data generates nautical charts, seafloor profiles, biological oceanography, etc. Water depth is collected using active sensors like sonar, lidar, or using passive multispectral imagery. Determining the bathymetry for a large area using sonar and LiDAR is very expensive. At the same time, a multispectral satellite can effectively determine the water depth and cost savings, especially for shallow water areas. In the coastal region, the nature of the bottom is very dynamic, and water is primarily turbid, which degrades the accuracy of satellite-derived bathymetry assessment. This study focuses on extracting water depth in Hai Phong’s coastal region (Viet Nam) by applying the ratio transform algorithm on Landsat-8 satellite imagery bands. The result shows a good correlation between the algorithm-derived and the sounding values.