Author(s): P. D. Thorne; D. Hurther; U. Lemmin
Linked Author(s): Ulrich Lemmin
Keywords: No Keywords
Abstract: The measurement of bottom boundary layer dynamics in the marine environment is fundamental for understanding the transport of sediments. To study the boundary layer requires contemporaneous observations of the bedforms, flow and sediment movement. The use of sound for such measurements has been pursued, because it offers the potential to measure simultaneously, collocated and non-intrusively, with high temporal-spatial resolution, profiles of the sediment movement, the flow and the bedforms. Combining the acoustic profiling capability with collocated hydrodynamic and sediment measurements, allows detailed visualisation of the complex processes of boundary layer dynamics to be constructed and these are providing new insights into fundamental near-bed processes. Here we look at recent developments in the use of acoustics for simultaneous measurements of; (i) bedforms at a millimetric scale using ultra-high resolution scanning, (ii) suspended sediment particle size and concentration using multi-frequency backscatter and (iii) the horizontal and vertical components of flow using pulse-to-pulse coherent Doppler phase techniques.
Year: 2009