Spatial variability of sediment roughness and its effect on reverberation

Abstract

As part of the environmental characterization supporting the Target and Reverberation Experiment in 2013 (TREX13), the Seafloor Laser-line Scanner (SLS) was deployed to measure sediment roughness at locations throughout the experiment site. The SLS uses structured light to create a two-dimensional digital elevation map of the seafloor over a 0.3 × 3.5 m area. This map is processed to determine the seafloor roughness power spectrum which is used to model backscatter from the seafloor. While a relatively shallow site for TREX13 was chosen to limit the area within which environmental characterization was required, there was significant variability in the sediment roughness which could not be sufficiently measured in the time available. To overcome this difficulty, data from a 400 kHz multibeam backscatter survey collected by de Moustier and Kraft have been combined with the SLS measurements to infer the roughness throughout the site. Although the reverberation modeling focuses on scattering wavenumbers that ...