A Study on Close-Range Underwater Detectors

Ultrasonic detection principle, proximity sensing, and system composition for proximity acoustic fuzes are analyzed. The needle shape disperse beam pattern of acoustic detector, having fine directionality, high sensitivity and high detection probability, has been adopted in the design, where high frequency, low power dissipation CW transmission that is used in shallow sea, with close range Doppler shift threshold have been selected for use. The searching area and acceptance range for small targets are discussed, and simulation has been done based on the acoustic detection device, using the Montecarlo method. The results have shown that the detection probability is almost linearly with improvement for motion relocity of intersection between sheel and target, with the detection probability exceeding 80% when the Doppler shift threshold is chosen at 3. It meets the requirement of the proximity acting radius.