Research On DOA Estimation Using Hybrid Acoustic Vector Array Based On Split Beam Process

The traditional sound pressure linear array is easy to be expanded in its array aperture,thereby obtaining a higher array gain and a azimuth estimation accuracy.Even though it is robust and in the mature development,there is a left-right ambiguous problem.The vector hydrophone can obtain the information of the sound pressure and the three-dimensional particle velocity synchronously and simultaneously,and has a dipole directivity.But the volume of the vector array is large,limiting its application in real scenarios.Its actual performance depends on the strict control or monitoring of the attitude of each vector hydrophone.This paper focuses on the hybrid vector array,which solves the above contradiction by complementing both advantages of two types of arrays.In this paper,the theoretical framework of the hybrid vector array signal processing for the plane wave is established firstly.The performances of the traditional direction-finding algorithms on the hybrid vector array are also investigated.The directivity of the hybrid vector array is studied,which provides theoretical guidance for the optimization and designing of the hybrid vector array.In order to make full use of the finite number of vector hydrophones,the split beam processing of the pressure array is extended to the hybrid vector sensor array.The main results and innovations of the thesis are as follows:(1)The broadband split beam correlation processing technology for the pressure array is investigated.It is found that with the whitening treatment,it has the characteristics that the output is independent of the incident signal and the noise power and the detection background is negative.Furthermore,it has certain anti-interference performance and the resistance to grating lobes aliasing,and thus the detection performance for weak broadband targets is outstanding.The results of sea trial data fully demonstrate the above characteristics and the advantages in complex scenarios.(2)For applying broadband correlation detection technology to the hybrid vector array,two methods are proposed.The first one is based on vector hydrophone directional sharpening technology,and the second one combines the directional electronic rotation and the whitening technologies.The results of a sea trial data fully prove the effectiveness of two methods,and also the effectiveness of the broadband correlation detection technology with the hybrid vector array.