Underwater Source Localization Using the Interference Pattern Matching in Range Dependent Environments

This paper proposes a method of underwater source localization using the wideband interference patterns matching in shallow water environments that vary in range. By matching two interference patterns in the spectrogram, it is estimated a ratio of the range from source to sensors, and then this ratio is applied to the Apollonius circle. The Apollonius circle is defined as the locus of all points whose distances from two fixed points are in a constant value so that it is possible to represent the locus of potential source location. The Apollonius circle alone, however, still keeps the ambiguity against the correct source location. Therefore another equation is necessary to estimate the unique locus of the source location. By estimating time differences of signal arrivals between source and sensors, the hyperbola equation is used to get the cross point of the two equations, where the point being assumed to be the source position. Simulations are performed to get performances of the proposed algorithm. The results show that the proposed algorithm successfully estimates the source position within an error bound of 10%.