Research On The Direction Finding Based On The Combined Processing Using Acoustic Vector Sensor Array

The acoustic vector sensor (AVS) is combined by traditional and omnidirectional pressure sensor and particle velocity sensor, which has natural dipole. It can measure both pressure and particle velocity of acoustic field at a point in space, whereas a traditional pressure sensor can only extract the pressure information. By taking advantage of the extra information, an acoustic vector sensor array (AVSA) is able to improve source localization performance without increasing array aperture size. In recent years, AVSA signal processing has been drawn much attention. And much work has been done for applying AVSA to the direction finding problem. However, these existing AVSA direction finding algorithms are all based on the same processing methodology that utilizes the particle velocity information of AVS as an independent array element (i.e. the particle velocity is regarded as an analog of the pressure information). Hence they don't make use of the pressure-velocity combined processing. In fact, there exists a coherence difference of pressure-velocity between radiated source signals based on the plane-wave model and the isotropic background noise. Therefore, the pressure-velocity combined processing has an outstanding ability to eliminate background noise in isotropic noise field.At the same time, subspace-based DOA estimation algorithms such as MUSIC, ESPRIT, and so on, have attracted a lot of attention in recent years due to its high resolution and low computational complexity. Recently, researchers has introduced them to the signal processing for AVSA successfully. As stated above, however, existing methods do not utilize the pressure-velocity combined processing, so its threshold SNR (signal-to-noise ratio) is still relatively higher.In this thesis we first review the fundamental principle of AVS, the physical basic of the pressure-velocity combined processing, as well as existing subspace methods based AVSA signal processing technologies. Its object is to investigate...