Estimating Deep Seafloor Interface and Volume Roughness Parameters Using the Multibeam-Hydrosweep System |
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Authors: | Bishwajit Chakraborty Hans Werner Schenke Vijay Kodagali Rick Hagen |
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Institution: | Division of Marine Biology and Fisheries, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA |
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Abstract: | Utilizing a hull-mounted, multinarrow beam echosounder onboard RV Polarstern, we measured variation of acoustic backscatter with incidence angles at two different sites in the Southern Oceans (Agulhas Plateau and the Riiser Larsen Sea). We modeled the data, using a composite roughness model, including water-sediment interface roughness and sediment volume roughness parameters. The model effectively uses the near normal incidence angle backscatter to determine the seafloor interface roughness parameters employing Helmholtz-Kirchhoff theory. Beyond 20° incidence angles, an application of Rayleigh-Rice theory is made by using a necessary splicing technique (combining both of the theories at 20° incidence angle). The estimated interface and volume roughness parameters are found to be in accordance with the known area geology. |
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Keywords: | Multibeam Echosounder Angular Backscatter Seafloor Roughness Composite Roughness Theory Southern Oceans |
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