TY - JOUR
TI - Investigation of Sonar Transponders for Offshore Wind Farms: Modeling Approach, Experimental Setup, and Results
AU - Fricke, M
AU - Rolfes, R
T2 - Journal of the Acoustical Society of America
AB - The installation of offshore wind farms in the German Exclusive Economic Zone requires the deployment of sonar transponders to prevent collisions with submarines. The general requirements for these systems have been previously worked out by the Research Department for Underwater Acoustics and Marine Geophysics of the Bundeswehr. In this article, the major results of the research project "Investigation of Sonar Transponders for Offshore Wind Farms" are presented. For theoretical investigations a hybrid approach was implemented using the boundary element method to calculate the source directivity and a three-dimensional ray-tracing algorithm to estimate the transmission loss. The angle-dependence of the sound field as well as the weather-dependence of the transmission loss are compared to experimental results gathered at the offshore wind farm alpha ventus, located 45 km north of the island Borkum. While theoretical and experimental results are in general agreement, the implemented model slightly underestimates scattering at the rough sea surface. It is found that the source level of 200 dB re 1 mu Pa at 1 m is adequate to satisfy the detectability of the warning sequence at distances up to 2 NM (approximate to 3.7 km) within a horizontal sector of +/- 60 degrees if realistic assumptions about signal-processing and noise are made. An arrangement to enlarge the angular coverage is discussed.
DA - 2013/11//
PY - 2013
VL - 134
SP - 3536
EP - 3545
UR - http://scitation.aip.org/content/asa/journal/jasa/134/5/10.1121/1.4823841
DO - 10.1121/1.4823841
LA - English
KW - Wind Energy
KW - Fixed Offshore Wind
KW - Navigation
KW - Human Dimensions
ER -