Coastal And Shallow Water Sea Bed Mapping Using Imagery-Derived Bathymetric Approach

摘要

Bathymetric mapping over coastal and shallow water region using vessel-based acoustic system is sometime hostile and inaccessible. It requires extensive amount of effort, time and money when it comes to the near shore and coastal region. Today, imagery-derived bathymetry has becoming popular and provides an alternative data gathering technique in particular the coastal and shallow water environment. The high refresh rate of imaging satellite data recorded every place on earth in high frequency rate has make it possible to distinguish the sea bed topography changes with periodic calculation of coastal bathymetries. Many initial attempts of using remotely sensed data and radiometric technique to estimate water depth over clear and shallow water had been developed since the past two decades. Throughout their remarkable efforts, a wide variety of algorithms for bathymetry retrieval have been developed and empirical models have been established to form the statistical relationship between image pixel values and water depth values. This paper highlights the ratio transform attempt proposed by Stumpf et al. to extract bathymetric information along the coastal region of Penang Island. Malaysia via Landsat-8 medium resolution (~30m) images. In the course of experiment, results have indicated that imagery-derived bathymetry technique can be valuable as a reconnaissance tool to vessel-based echo sounding survey. Conversely, multispectral imageries offer safe, time- and cost-effective solution to map the sea bed topography over broad areas.