Shallow-Water Bathymetry Estimation at Pantai Tok Jembal, Terengganu, Malaysia Using Landsat 8 (OLI)

Abstract

Satellite-derived bathymetry (SDB) emerging as a cost-effective that provides high-resolution mapping over a wide area. This method can map shallow water environment, especially that are difficult to access by boat or airplane. SDB is not for replacing the conventional bathymetry method but to assist. The accuracy of SDB does not meet current International Hydrographic Organization (IHO) S-44 standards but still can use when planning hydrographic surveying, i.e., unsurvey areas or areas with old data. In this paper, the SDB method applies to produces bathymetric mapping at Pantai Tok Jembal, Terengganu, Malaysia. Derived from Landsat 8 images and for the bathymetry method use is an empirical-based method, Log-ratio Transform. To diversify the result, utilizing three atmospheric correction approaches: No. atmospheric correction, Dark Object Subtraction (DOS), and Fast Line-of-sight Atmospheric Analysis of Hypercubes (FLAASH). The SDB result then evaluates using Single Beam Echo Sounding (SBES) ground truth data. The result indicates that Log-ratio Transform with DOS atmospheric correction produces the best result based on the error analysis. The error mostly occurs when there is no data available in the particular area due to cloud cover and shallow water area, i.e., inaccessible boat or vessel area. The error also occurs as it goes deeper area where the light is limited. In conclusion, this study successfully produces bathymetric mapping at Pantai Tok Jembal, Terengganu, Malaysia, through the SDB technique. This method strengthens the SBES data by effectively filling the data gaps; however, further research needs to fulfill this support in giving high accuracy and reliability.