Target strength calculation of bubble cloud generated by diver based on dimension distribution

Abstract

Underwater diver is a critical object to research in underwater target detection. The key scattering factors of a diver include human organs, dry diving suit, scuba bottle, open-circuit bubble cloud, etc. Of all these factors, open-circuit bubble cloud is the most important. It is well known that the target strength (TS) of bubble cloud can be calculated by the TS of a single bubble with preset dimension. Such algorithms are based on the hypothesis that bubbles are of the same dimension, which is not true in real underwater environment. The distribution of bubble dimensions always follows some certain law. In this paper, a multi-dimension acoustic scattering model of bubble cloud was established through introducing the probability distribution function of bubble dimensions. And based on the proposed multi-dimension model, the TS of bubble cloud were calculated more precisely to meet the requirements of detection. Numerical simulation demonstrates that the validity of the proposed model which can truly describe the acoustic scattering characteristics of bubble cloud is over the single-dimension model.