Cylindrical sonar design for fish echo surveying

Abstract

Most applications of echo integration involve use of a fixed single-beam transducer that is rather narrow and downwards-oriented. It is often desired to sense fish in other directions, for example, to assess components of the fish stock which may be avoiding the surveying vessel. To assist in discussions of a general solution, a cylindrical sonar design is proposed. Such a sonar would be carried in a towed body, allowing detection and localization throughout the plane transverse to the vessel track. Beam patterns, equivalent beam angles and other measures of performance are computed for a range of frequencies and aperture sizes.