Bathymetric Extraction using Overlapping Orthoimages

This paper further explores bathymetric extraction techniques using overlapping orthoimages in shallow water areas through two-medium ray refraction and multispectral information inversion. In texture-rich areas, a ray refraction method using overlapping orthoimages is developed to calculate the depth information of the underwater features. In texture-less areas, the commonly-used multispectral inversion techniques are applied. The depth information from the ray refraction method acts as the references for the multispectral inversion techniques, therefore, an integrated approach of extracting the shallow bathymetry based on overlapping orthoimages is formed. The results from an aerial overlapping orthoimages experiment show that 0.5 m accuracy can be achieved in the study area. The proposed approach is the combination of two simple methods, and is easy to be implemented and flexible to use, giving that there are a large amount of existing overlapping multispectral orthoimages in water related areas, the proposed approach has the great potentials for the practical use.