Research On The Detection Technology Of Underwater Small Target

Underwater frogmen constitute a significant threat to the ports, terminals and militaryinstallations. Currently the effective warning and detection means is still lack. An active andpassive acoustic characteristic of the underwater frogman at home and abroad is relatively fewand relative lack of basic test data.This paper is based on pilots, in the experience there are two ways of frogman detection.One of the methods takes the use of the sound radiation characteristics of frogman to passivedetection; the other method takes the use of sound scattering characteristics of frogman todetect by active sonar. In the passive detection mode, the measurement experiments on theradiated noise of underwater frogman is taking, measuring the source level and power spectralcharacteristics of the its breathing noise, the trash noise and bubble noise, using the vectorhydrophone on the target tracking and positioning and taking simulation and experimentalvalidation. In the active detection mode, active sonar transmits sound waves to the frogmanmeasuring the target strength on different frequencies, different attitude of frogman and thepower density of echo.This paper focuses on the acoustic properties of underwater frogman, to provide atheoretical basis for the identification and detection of frogman. Meanwhile, the realizablemeans of detecting frogman is also studied in this paper, which has a certain value on thedesign of frogman detection sonar.