Analysis for approach of passive measurement based on waveguide invariant

Abstract

Nowadays, the development of underwater acoustic positioning and measuring direction technology becomes more and more important. A method which belongs to a passive direction based on waveguide invariant, could be used to measure a heading angle of a target source with guide source technology, combined with a single acoustic vector hydrophone at a low frequency in the epicontinental. At first, in the epicontinental ocean, at a low frequency, simulating the channel of ocean according to normal mode theory using the software called KrakenC. Then, the vector acoustic pressure field could be calculated, getting the schematic diagram about a stable interference structure of epicontinental ocean in a low frequency. Waveguide invariant could describe the situation about that. To pick up, waveguide invariant becomes the most important part of this paper. This process get with the movement of the guide source and the target source; also, an image processing method called Hough transform is essential. Finally, waveguide invariant is acquired. At the same time, by that, the heading angle of the target source is easy to be estimated. When detailed information of the ocean have not acquired enough, this method still works well, and simulation data for the experiment prove the feasibility of the model.