Satellite-derived bathymetry for shallow coastal waters in Cyprus

Abstract

During the last years, many studies related to Satellite-Derived Bathymetry (SDB) emphasize the potential use of optical satellite remote sensing sensors for bathymetric estimation. For this study, ten multispectral SPOT 6/7 satellite images with a medium resolution covering the coastal waters of the study areas were analyzed. These images were geometric, radiometric, and atmospheric corrected and acquired in three different sensing dates having coverage with at least 30% of lidar data. A number of 5284 random depth measurements with 0 to 50 meters depth were acquired for the ratio conversion algorithm with absolute depths and error assessment. A series of steps were performed to obtain reliable results using satellite optical data such as, sun glint process, land/sea extraction, kernel filters. The study area was divided into three sub-regions, based on the sensing date of the satellite imageries. The light attenuation in the water column increases at a depth of about thirty meters as seen in other related studies. This study identified the depth of light attenuation to determine the maximum depth that can be estimated through optical sensors. The results show that better correlation was identified up to 15 meters depth. Results of the regression analysis show the following correlation coefficients R² :0.90, 0.87, 0.80, and 0.89 with the Root Mean Square Error (RMSE) for the respective study areas to be 1.34, 1.53 1.70 and, 1.15.