Sediment classification by acoustic methods - ACOUSEC final report

Abstract

Keywords: Sediment classification ; Remote sensing ; Seabed sediments ; Software ; Geophysics ; Seafloor topography ; Backscatter ; Multibeam bathymetry ; Acoustic classification\rSummary:\rAcoustic classification of sediments using single beam and multibeam echo sounders had been under intense development over the past two decades. In the ACOUSEC project, led by Kongsberg-SIMRAD and co-financed by NFR, the goal had been to improve methods and algorithms for acousitc classification, and try to establish acoustic libraries that could minimise the need for ground truthing. NGU had aquired single beem data, evaluated software for multibeam echo sounder classification, and provided sediment samples and sediment maps for calibration of results. Field data have been aquired from the Sula Reef, the Røst Reef Complex, from the TESI area at Møre, from Harstad, Trondheimsfjorden and around Jøa. The evaluation of classification software reveals that backscatter data quality is a critical factor for acoustic classification. This applies both to calibration during data aquisition, and the software used for processing and intepretation. The report concludes that there are important improvements to be done before semi-automatic classification can be performed on the backscatter data, providing a reasonably reliable sediment map.