Repository hosted by TU Delft Library

Home · Contact · About · Disclaimer ·
 

Shape and Doppler corrected beamforming for low frequency active sonars

Publication files not online:

Author: Groen, J. · Beerens, S.P. · Doisy, Y.
Type:article
Date:2004
Publisher: Nexus Media Ltd
Place: Swanley, Kent, UK
Institution: TNO Fysisch en Elektronisch Laboratorium
Source:UDT Europe 2004 - Conference Proceedings Undersea Defence Technology, 22-25 June 2004, Nice, France, 1-7
Identifier: 242087
Keywords: Warfare · Antisubmarine warfare · Shallow water · Beam forming · Low-frequency active sonar · Towed array sonar

Abstract

ASW operations have shifted toward shallow water environments, where water space is limited and manoeuvring an essential part of operations. The problem that is tackled in this article is the performance loss due to the shape and motion of a manoeuvring sonar. Standard beamforming in towed sonar arrays is based on the assumption that all hydrophones move on a straight line with constant velocity. However, when the tow ship turns the array follows and gets bent. The two damaging effects are deviation from the straight line and variation in Doppler. In 2002 and 2003 dedicated operational high-speed experiments with tow ship manoeuvres were conducted to illustrate and tackle the problem. The solution starts with estimation of the dynamic sonar element positions. Subsequently these estimates are incorporated in the beamformer and/or matched filter. A new method for shape and Doppler corrected processing are developed and validated on simulated and experimental data.