Paulo Felisbertopfelis@ualg.pt
and Sergio M. Jesus sjesus@ualg.pt
Universidade do Algarve,
Campus de Gambelas, PT-8000,
Faro, Portugal.
Comments: download pdf file or with
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Ref.: IEE Proc. Radar, Sonar and Navigation, vol. 143,
no. 3, p. 210-215, 1996.
Abstract
Towed hydrophone arrays are commonly used for determining the spatial
characteristics of the underwater acoustic field. The assumption that
the hydrophones lie in a straight and horizontal line is often made
when beamforming the hydrophone outputs. However, due to tow
vessel motion, ocean swells and currents the array adopts a nonlinear
shape and the beamformer output is degraded. To estimate the positions
of the hydrophones, an array was instrumented with a set of positioning
sensors: compasses, tiltmeters, accelerometers and pressure gauges.
This paper presents the array deformations recorded at sea when the tow
vessel is turning and along straight line tracks. The influence of the
observed deformations on the performance of the conventional beamformer
output is discussed and ilustrated with simulated and real acoustic
data.
ACKNOWLEDGMENT: this work was partially supported by the EU project MAS2-CT920022.