A Technique to Measure the Breathing Wave Speed in a Towed Array

Abstract

A method is developed for measuring the breathing wave speed in a towed array. The front of the array is longitudinally vibrated, producing aft-traveling wave energy that is detected by measuring the transfer function of a hydrophone channel and a forward bulkhead-mounted accelerometer. The transfer function is composed of two distinct wave types: an extensional wave and a breathing wave. The breathing wavelengths are much shorter than the extensional wavelengths; therefore, the local minimum associated with the first breathing wave null across the hydrophone channel can be identified. Because the frequency at which this null occurs and the length of the hydrophone channel are known, the breathing wave speed can be calculated.