Transponder/Pinger relocation receiver

This paper describes the development of a range-bearing acoustic receiver used to relocate a single underwater transponder, navigation beacon or pinger. Basically a hydrophone array consisting of two crossed dipoles and associated signal processing electronics determine the bearing of a pulse of sinusoidal acoustic energy by phase comparison techniques. This technique provides operation over a full sector without ambiguous results. The physical size of the hydrophone array is relatively small since spacing between elements is less than half a wavelength (at 10 kHz, inches). It will be shown that the physical and signal processing parameters can be arranged so as to display in analog form a bearing sector on a section of a deflection meter movement. Range to the underwater device is determined by measurement of total travel time taking into account equipment decision time.