Target DOA estimation combined processing method in shallow sea multipath environment

Abstract

The invention provides a target DOA estimation combined processing method in a shallow sea multipath environment, and the method comprises the steps: firstly carrying out the extension of a fourth-order cumulaarget DOA estimation combined processing method in shallow sea multipath environmentnt on array receiving data, and obtaining an extended fourth-order cumulant matrix; then carrying out decorrelation processing on the expanded fourth-order cumulant matrix to obtain a received data covariance matrix; finally, carrying out characteristic decomposition on the covariance matrix of the received data, and calculating a corresponding signal subspace and a noise subspace; and performing DOA estimation to obtain a final target direction value. According to the method, the incident angles of the multiple coherent signals of the underwater target can be effectively estimated in the shallow sea environment with serious multipath effect interference by using the non-uniform linear array with a small number of array elements in actual engineering application, and the method still has relatively good estimation precision and relatively low calculation complexity under a low signal-to-noise ratio and has good estimation performance.

Description

technical field [0001] The invention relates to the technical field of underwater target passive orientation, in particular to a joint processing method for target DOA estimation. Background technique [0002] As one of the key technologies in the marine defense system, the precise orientation technology of underwater targets plays a very important role in many national defense and civilian fields such as radar, sonar, underwater weapons, submarine geological survey and marine resource development. However, with the development of various target simulation technologies, stealth technology, and the influence of the complex and changeable ocean environment, it is becoming more and more difficult to accurately orient underwater targets. Accurate orientation of the target is an urgent problem to be solved. [0003] In the complex shallow sea environment, the multipath effect is the main factor affecting the passive orientation accuracy of the target. When the underwater detect...

AI Technical Summary

Problems solved by technology

However, the shallow sea environment is extremely complex and changeable, and the acoustic signal is easily disturbed in it, which cannot guarantee effective and stable transmission, which has an impact on the application of conventional DOA estimation algorithms underwater

[0005] In addition, most of the current DOA estimation methods for underwater target detection systems are aimed at uniformly spaced linear arrays, but in practical engineering applications, due to the constraints of underwater equipment and other conditions, underwater target detection systems are often not ideal. uniform line array

In engineering practice, it is often necessary to use a non-uniform line array, and the conventional line array orientation method cannot be applied

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