ERRORS IN DEPTH DETERMINATION CAUSED BY WAVES IN THROUGH-WATER PHOTOGRAMMETRY

The determination of depths in shallow water from aerial platforms will become increasingly important as exploitation of coastal resources intensifies. Until a theoretical study of the errors in depth which could be reasonably expected from two-media photogrammetry was made by Okamoto in 1982, there was little relevant literature apart from some isolated case studies. This paper examines the magnitude and distribution of errors in depth caused by the presence of waves on the water surface. The effects of random errors of observational measurement, in combination with waves, are assessed. A conclusion is reached that the traditional method of underwater depth calculation should be modified when the scale of the two media photography is greater than 1:4000.