Underwater wideband source localization using the interference pattern matching

Recently many studies have been performed to detect underwater target by sensor network. This paper proposes an underwater source localization method based on wideband interference pattern matching. Matching of two interference patterns which seen in the sensor spectrograms, estimates a ratio of the range from source to two sensors according to the waveguide invariant theory and this ratio applied to circle of Apollonius. The circle of Apollonius is defined as the locus of all points whose distances from two fixed points are in a constant ratio so it is possible to represent the locus of potential source location. However, since ambiguity of absolute source location so it requires that additional equation which estimates another locus of the source. Therefore the hyperbola equation by estimating TDOA (Time Difference Of Arrival) is introduced into localization and finally cross point of two equations can be estimated as the source location. We performed simulation to test performance of the proposed localization method and then practiced error analysis of the results. And we tested performance of capability from a real-data collected during sea experiment. From simulation and experimental results, proposed algorithm represents that estimated position of target showed error of within 10%.