A high-resolution electronic sector-scanning sonar

The success of sea-trials of an experimental pulsed sonar system using `within-pulse¿ electronic scanning has led to the development of a new version using a considerably larger number of channels and a shorter wavelength in the water. The new system, which has 30 channels and works at a carrier frequency of 500 kc/s in the water, is designed for a maximum range of 100 yards and a scanned sector of ± 15 deg. Pulse lengths down to 100 ¿s can be used, corresponding to a range resolution of about 6 in. Facilities are provided to permit a rapid change-over from normal additive signal processing to a multiplicative process which is capable of approximately doubling the angular resolution of the system, at the expense of some reduction in effective maximum range. Initial trials have confirmed that the performance of the equipment meets the design specification.