The Study Of Wake Bubble Distributing Characteristics Based On Optical Characteristics

Wake is motive bubble film. Wake optical characteristics and application is a new domain of international and national of science research, it has an important significance in military and civilian industry. The technique for detecting and tracing the underwater object such as fish stocks or ships, based on optical properties of wakes, breaks the conventional way of using sound field, but uses light wave as the information carrier, which makes the conventional acoustics disturbance and the countermove useless. Besides it has farther detection distance, higher hit probability and non-interference of electromagnetic noise or ambient noise. The research of motive bubble is the basis of wake research, making use of digital image processing technique to study distributing characteristics of motive bubble film is a fire-new detection and analytic method. Compare with traditional detection method of motive bubble, it has a lot of advantages. Such as visibility, high-efficient and real-time. In this dissertation, achievements in the theoretic and experiments are as follow:In the theoretical study, using Mie theory, single-scattering properties of a clean and dirt bubble and phase functions of bubble populations for wakes in the absorbing sea water are calculated. The method that wake bubbles may be effectively detected is theoretically estimated.In the experiment, based on the optical characteristics of motive bubble film, designing a collection system of motive bubble. First, based on the characteristics of bubble, analyze the demand of image collection system and choose suitable illuminating method, then construct the experimental system and collect many images of motive bubble for following processing. Making use of traditional digital image processing method and wavelet transform to process the image of motive bubble, then acquire the geometry and movement characteristics, confirm the feasibility of these two methods.