Analysis of dredger noise based on experimental and simulated source level calculations

TitleAnalysis of dredger noise based on experimental and simulated source level calculations
Publication TypeConference Proceedings
Year of Publication2015
AuthorsSantos Domínguez, D
EditorTorres Guijarro, S, Pena Giménez, A
Conference NameUACE
Date Published06/2015
AbstractThis contribution is part of a dredger innovation project (ECODRAGA) aimed at reducing the pollution produced by suction dredging operations where one of the objectives was to evaluate the effect of the dredger modifications over the underwater noise generated. Measurements of the dredger working in ECO and conventional mode were made, also a methodology to obtain Source Levels was proposed with both experimental and software methods. Hydrophone measurements of the dredger were made in Moaña port in Pontevedra (North West Spain), a shallow water zone in Ría de Vigo (a drowned river valley). Noise measurements where accompanied with oceanographic sonde (CTD) measures, obtaining salinity, temperature and speed of sound depth profiles of the measurements zone. To obtain Source Levels of the Eco-dredger two propagation losses calculation methods were used: the first experimental one consists in the use of a calibrated source emitting single tones, in the same position as the dredger during the measurements, to calculate propagation losses of each 1/3 octave band from 125Hz to 4kHz. The second one is a simulation and analysis of the first setup using the software “dBSea”. ”dBSea” is the first commercial software of 3D underwater noise estimation with 3D bathymetry and 3 different calculation algorithms: parabolic equation, normal modes and ray tracing. All algorithms were tested and analysed to determine which one fits better with the measurements made. Conclusions compare the use of both propagation losses calculation methods and their application to the computation of the dredger source level.
Citation Key622