Multibeam echo sounders (MBES) continue to evolve as sonar hardware manufacturers improve their engineering designs and capabilities. MBES systems can now collect very high-resolution data sets over a range of frequencies during a single vessel pass (via multispectral systems). The development of these sensors has outpaced their scientific testing. Linking acoustic backscatter measurements to seafloor environmental parameters (e.g. substrate and habitat characteristics) is complex. Detailed investigation of these acoustic/seafloor relationships through field tests are lacking or dated - based on results from acoustic modelling conducted several decades ago. As a result, data processing approaches often lack standardization, which can impede use of these data for seafloor characterization and mapping.
 

The aims of WP4.3 are to:

1. Collect backscatter data sets from the latest generation of MBES systems under controlled experimental conditions at suitable field sites in Canada, Germany, and Brazil [tasks 4.3.1, 4.3.2]

2. Conduct extensive, spatially georeferenced ground truthing to comprehensively characterize seafloor geological properties (e.g. grain size, intermediate scale roughness, geotechnical measurements, etc.) [tasks 4.3.2]

3. Compare seafloor measurements to MBES acoustic backscatter at the full range of ensonification angles across the MBES swath [task 4.3.4]

4. Compare how these measurements vary over different substrate types and in different environmental settings/locations [tasks 4.3.3, 4.3.4]

5. Evaluate to what extent Angular Range Analysis of the backscatter signal over different operating frequencies can be used to predict seafloor sediment characteristics [task 4.3.4].