Side-scan sonar techniques for the characterization of physical properties of artificial benthic habitats

Abstract

A B S T R A C TSide-scan sonar observations conducted at Mito artificial habitat site in the southwest coast off Taiwan, documented the locations of both concrete cubic blocks (more than 10,000 units) and scrapped steel boats (39 units) deployed previously. Based on their geographic locations, the concrete cubic artificial reefs could be grouped into 14 reef sets. About 30% of the reefs were deployed out of the promulgated site area. For the purpose of artificial habitat site identification and fishery resources management, a database structure was designed to accommodate types and positions of reefs, information of reef sets, bathymetric contours, textures of bottom sediments and geomorphological characteristics. The effectiveness of Mito artificial habitat site was evaluated to be positive after the deployment of both concrete block reefs and steel boat reefs. R E S U M OObservações com sonar de varredura lateral ao largo de Mito na costa sudoeste de Taiwan, revelou a localização de mais de 10.000 blocos de concreto e 39 embarcações de ferro assentados previamente como recifes artificiais. Com base nas imagens obtidas, os cubos de concreto formam 14 grupos separados. Cerca de 30% das unidades de concreto foram assentadas fora das áreas previstas. Para a identificacão correta dos recifes artificiais e manejo adequado dos recursos pesqueiros, foi organizada uma base de dados com informações sobre forma, materiais e posição, e arranjo espacial das unidades recifais, bem como dados de batimetria, natureza do sedimento do fundo e geomorfologia. A eficiência dos recifes artificiais de Mito foi avaliada positivamente após o assentamento tanto das unidades de concreto quanto das embarcações de ferro.

Automatic Detection of Trawl-Marks in Sidescan Sonar Images through Spatial Domain Filtering, Employing Haar-Like Features and Morphological Operations

“…The acoustic backscatter images are getting acquired and transmitted under the presence of ambient noise [79]. Acoustic artifacts such as stripe noise by roll towfish motion or other electrical noise deteriorate the quality of the sonar image [80]. According to Wilken et al [81] in most cases SSS mosaics are affected by visible stripe noise.…”

Discovery and Excavation of Artifacts from the Bidong Shipwreck, Malaysia

“…In marine archaeology, side-scan sonar has been ubiquitously used to locate potential archaeological sites and map seabed areas (Ballard 2007; Bowens 2009; Green 2004; Plets et al 2011). Sonar principles, underwater side-scan sonar operations, and sonar designs have been discussed comprehensively by Kinsler and colleagues (1982), Urick (1975), and Tian (2010). The basic techniques used in the Bidong Shipwreck excavation program followed the guidelines of side-scan sonar, which referred to the “Manual for activities directed at underwater cultural heritage” (Maarleveld et al 2013) as recommended by guidelines to the Annex to the UNESCO (2001) Convention.…”

Contour Extraction Based on Adaptive Thresholding in Sonar Images

“…Side-scan sonar is also used for fisheries research, dredging operations, and environmental studies. Multi-frequency, multi-sonar echosounders are used for benthic habitat mapping [7,8].…”