Satellite-based Bathymetry Supported by Extracted Coastlines

Bathymetry is the measurement of ocean depths using a variety of techniques. Available techniques include sonar systems, light detection and ranging (LIDAR), and remote sensing systems. Acoustic systems, also known as LIDAR, are inefficient in terms of both time and money. This study applied remote sensing techniques to reduce both time and cost. The objective of this study is to use freely accessible Sentinel‑2 multispectral images to extract the depth information. Temporal variation was minimized by comparing the histograms of satellite images obtained over four consecutive months. The sea topography is determined using regression analysis, utilizing samples from reference data. The reference data is adjusted with the changes in shorelines, as the alteration of shorelines serves as a parameter for these modifications. Using the regression coefficients, analyses were conducted in regions with undetermined depths. The bathymetry maps were evaluated against a reference dataset and improved by incorporating shorelines. The analyses were carried out individually over four months, and the derived bathymetric data showed significant monthly average and monthly shoreline changes. The employed methodology offers an alternative approach for bathymetry studies that require temporal resolution when the available reference bathymetric data is insufficient.