Study And Analysis Of Three Sensor Array Passive Ranging Of Near Target In Shallow Water

Three-sensor array passive ranging is a well-known traditional technology, which is used to estimate the targets' range and direction through the curvature changes of spherical wave front using time delay estimation (TDE). The precision of ranging is related to TDE precision, target's range and direction, aperture, installing precision. The impact of TDE precision is the most significant in above factors.In the published paper, the researches of three-sensor array passive ranging mainly focus on submarines which work in the deep sea, and the analysis are mainly concerned far field targets while the near field targets are less mentioned.The thesis aims at studying the performance of three-sensor array passive ranging to near targets in shallow water. The array is laid on the seafloor of the shallow water.The accurate formula of three-sensor array passive ranging suitable for the near field are given in the thesis which are used to process data, the factors which mainly affect the results' precision are discussed.Instead of the conventional cross correlator, the sliding cross correlator is used to estimate the time delay, the advantages of the sliding cross correlator and the effects of sliding times are demonstrated by computer simulating and data processing. At the same time, a post processing method consisting of "round filter" and "dynamic filter" is presented in the thesis. On condition that the high quality data ratio is above 50%, the method can eliminate all flaw points and doesn't rely on future input, which can be used in real-time environment, and the method is validated by simulating and experimental data processing. At last the ranging results are compared to the GPS with 20cm precision and the error is just only several meters.