Investigation into laboratory bathymetric measurement techniques

Abstract

There is no universally accepted way to accurately and efficiently measure bathymetry in laboratory hydraulic models. Remote sensing techniques can measure bathymetry without making contact with the model, and some remote sensing techniques can measure the bathymetry in laboratory models without draining the water. The four categories of remote sensing technology investigated in this report are echo sounding technology, laser technology, image processing technology, and radar technology. The technology of each category has strengths and limitations, but can be used in the laboratory to measure bathymetry. Echo sounding technology works well in environments with suspended sediment, but the accuracy is reduced by large beam footprints. Laser technology does not perform as well with suspended sediment but can provide high-accuracy bathymetric measurements. Stereophotography, discussed in the image processing technology section, requires optically clear water and can provide very accurate bathymetric mapping. Radar technology can be very helpful when sub-bottom stratigraphy is important. Technology from each of the categories has been scaled for field application to measure bathymetry and submerged coastal structures.