Gamper L.E., Popova O.S.
The paper describes a method for passively determining the distance to an underwater source using the curvature of the wave front of the source field in the Fresnel zone. The synthesis of algorithms for the optimal spatial and temporal processing of information from a system of a hydroacoustic receivers providing signal detection and determination of source parameters, as well as observing their location in a given direction sector and range, is based on the likelihood ratio equation. If there is more than one source in the observation area, the detection of a weak signal of interest to the observer and the determination of its parameters can be difficult due to its side field suppression of a strong source, a shift in the estimate and an increase in the fluctuation error. The article discusses the algorithm of rejection of the interfering signal before carrying
out the basic procedures of passive sonar, which reduces the influence of a strong source on the evaluation of the parameters of a weak signal. Calculations of the accuracy of distance estimation using the rejection algorithm and without it are given.