Shallow water bathymetry from WorldView-2 stereo imagery using two-media photogrammetry

Two-media photogrammetry appears to be a useful technology for mapping shallow water depth. The objective of this paper is to explore the feasibility of shallow water bathymetry using satellite two-media photogrammetry. This paper presents a two-media photogrammetry technique for WorldView-2 stereo multispectral imagery. In this method, near-infrared band is used for sun glint elimination. A combination of Scale Invariant Feature Transform and Semi-Global Matching algorithm is adopted for dense stereo matching. Rational Function Model is applied for raw Digital Elevation Model generation and the water surface elevation is determined by interpolating water edge elevation. Finally, the approximate refraction correction model is adopted in the water region to correct the vertical coordinate offsets. Our experimental results of Ganquan Island and Zhaoshu Island show that a reasonable depth estimate with relative error less than 17% and 14% can be obtained for the water depth range between 5 and 20 m, and the root-mean-square error are 2.09 m and 1.76 m, respectively. However, less accurate estimate is found for the very shallow water depth range between 0 and 5 m. The overall accuracy of satellite two-media photogrammetry is at the same level with the traditional multispectral-based model for bottom depth retrieval.