Quantitative Side-Scan Research for Sediment Characterization and the Development of a Multibeam Subbottom Profiler

Abstract

The long-term goals of this work are to contribute to the understanding of bottom backscatter at high frequencies, provide techniques for determining sediment characteristics based on backscatter, and to support experiments within the context of the high-frequency, underwater communications and bottom scattering experiments such as KauaiEx and SAX04. An additional goal, recently established for this project, is to contribute to an improved understand of shallow-subbottom backscatter at mid-range frequencies. OBJECTIVES Our main objective is to contribute to the understanding of seafloor backscatter at high and mid-range frequencies. Additionally, in support of bottom scattering projects, another principal objective is to provide wide-area, high-resolution data to describe the nature of the bottom/subbottom and to develop a means of classifying bottom characteristics based on backscatter signals. These objectives require an understanding of the statistical nature of the backscatter signal and how to delineate changes in the bottom based on changes in the statistics of backscatter through the collection of several data sets including KauaiEx and SAX04 data. This work contributes particularly an understanding of the broadarea, spatial variation of the statistics of backscatter. Often bottom-scattering is determined for a series of isolated bottom points with little or no spatial connectivity. APPROACH The main focuses of our work in FY06 were to further the high-frequency backscatter analyses of the KauaiEx and SAX04 data and to plan and construct the Multibeam SubBottom Profiler (MSBP) that was initiated later in FY05 by ONR with Defense University Research Instrumentation Program (DURIP) funding. Several presentations were made as a result of these analyses and several are pending. A paper was completed on the Kauai work and submitted. No new data collection efforts were initiated in FY06. Other resources to support new data collection have been sought and secured for new surveys in early FY07.