Detection Of Source Number And DOA Estimation Of Wideband Signal Based On Uniform Circular Acoustic Vector Sensor Array

Circular array is widely used in sonar system.It can provide 360 degrees,unambiguous azimuth information.Because of this,sonar buoy and airborne dipping sonar system usually use circular array.In recent years,the acoustic vector sensor is developing rapidly,and it is gradually popularized in the linear array.And at present,acoustic vector array processing is almost all based on vector linear array.Compared with the fruitful results of vector linear array,the research of acoustic vector circular array is relatively scarce.Broadband signal is the frequently used signal form of the underwater acoustic system.Underwater target radiation noise can be divided into linear and continuous broadband spectrum.And the latter has the advantages of carrying a lot of information and weak background noise,which are beneficial to the targets detection and parameter estimation.Therefore,it has important engineering application value to carry out the research on the DOA(direction of arrival)algorithm of underwater remote broadband source.And it is very essential to study the wideband signal of acoustic vector circular array in this paper.This paper studies the source number estimation and azimuth estimation of acoustic vector circular array wideband signalsthrough theoretical analysis and computer simulation.Most of the high resolution direction estimation algorithms need to know the number of sources or assume that the number of sources is known.If the estimated number of the source is not in conformity with the true number of sources,the performance of the DOA estimation method will be seriously affected.Source number estimation can provide signals number for azimuth estimation.Therefore,accurate estimation of the number of sources is needed before the azimuth estimation is carried out.In the aspect of source number estimation,this paper realizes the wideband source number estimation of acoustic vector circular array by simulation.And the estimation of signals number is realized by using the information criteria or Gerschgorin radii.In the aspect of DOA estimation,firstly,the theory and simulation research on the DOA estimation of non-coherent wideband signals are studied.This paper realizes and analyzed both the advantages and disadvantages of MVDR,MUSIC and other high resolution algorithms,and has mainly analyzed the performance of DOA estimation of wideband signals with different sound pressure and particle velocity combined treatment.Theoretical analyses and simulation results show that the combined processing method ofP*(?)has better DOA estimation performance compared to the same manifold of circular pressure sensor array and other combined processing methods of pressure and particle velocity(such as(P+V_c)andP*V_c.Secondly,due to the multipath effect,the source of different directions may be related to or even coherent,and with the increase of measurement distance,the signal to noise ratio decreases,and the performance of the azimuth estimation is decreased.When sources are correlated or coherence,the performance of DOA estimation will also degrade.In order to distinguish between coherent wideband targets,the spatial smoothing,matrix decomposition and the vector singular value are realized by simulation.Based on the existing solutions of coherent algorithms(such as spatial smoothing,vector singular value decomposition),a modified vector singular value decomposition algorithm is introduced.It is also discovered that the proposed method combinedP*(?)with the modified singular value decomposition algorithm can effectively resolve the coherent sources and reduce the threshold of SNR.Meanwhile,the validity of theintroduced methodsis proved by the pool experimental.In addition,the proposed method has a widely application in radar system and air acoustics.