Sector-Scanning Sonar Imagery of Laboratory Bedforms
Thursday, 18 December 2014
High-frequency (2.25 MHz) Sector-Scanning Sonar (SSS) provides low-cost imagery for observing bedform morphology. SSS data can be used to improve upon bedform morphology models and correct for acoustic scattering and absorption of the seafloor. We collected SSS data at a 3.0 m range over six days in the large wave flume at the O.H. Hinsdale Wave Research Laboratory at Oregon State University. SSS data were averaged over the number of scan passes for each experiment. Experiments were conducted using solitons, as well as cnoidal and random waves with varying wave heights and periods from 0.25 m to 1.0 m and 2.0 to 5.0 seconds, respectively. Waves propagated over an 8 m long sediment test section containing Oregon beach sand with D50 = 0.23 mm. Ripple wavelengths were estimated using Fourier analysis and ranged from 0.41 m to 1.2 m.