Measurement of bottom backscattering strength using single-beam echosounder

A quantified single beam echosounder was applied to detect and quantify the bottom echoes. Bottom backscattering strength (SB) is necessary to be quantified for accurate seabed mapping and classification. The SB can be measured by Lambert's Law that enabled to interpret the bottom echo and to measure the SB values. The research was conducted in Tidung Island, Jakarta which had several seabed types, such as coral reef, seagrass, sand, silt, clay, mud, and mixed sediment. Acoustic data was acquired using SIMRAD EK15 with the frequency of 200 kHz and sediment grain size was analyzed using Wentworth grain size classification. The results show that the backscattering of each seabed type is different. Sediment with greater mean diameter had greater SB value, and seabed with rougher surface had greater SB value as well.