High accuracy ESPRIT without left-right ambiguity using an acoustic vector sensor array

Abstract

Through in-pressure sensor array signal processing, the signal arrival angle can be estimated by the estimation of signal parameters via rotational invariance techniques (ESPRIT) if we regard the whole array as two sub-arrays with the same structure. The estimation angles arrived at by ESPRIT have a left-right ambiguity because of the inverse trigonometric function operation. An acoustic vector sensor array (AVSA), which measures particle velocity and pressure at the same time and point of the acoustic field, offers significant potential. The traditional ESPRIT algorithm can also be used for an AVSA with left-right ambiguity. A new algorithm with omnibearing and an high accuracy based on ESPRIT using an AVSA was proposed in this paper. An analytic particle velocity, which composes by acoustic vector sensor x-axis and y-axis velocities, embeds the signal angle in its phase. The signal broadside can be known by the ESPRIT based on analytic particle velocity and pressure sub-arrays. The estimation angle containing broadside information can be used as the driving angle for combined particle velocity. According to the signal broadside, an average cross-variance matrix of pressure and combined velocity was constructed. The signal angle can be estimated by ESPRIT based on this new combined cross-variance matrix. Theoretical analysis and computer simulations show that the proposed algorithm has no left-right ambiguity and also has higher accuracy than the analytic particle velocity algorithm in the case of low signal-to-noise ratio (SNR). The algorithm is based on pressure and particle velocity combined processing, which can suppress interference better than existing algorithms in isotropic noise. The algorithm is also based on the analytic particle velocity ESPRIT, which has no left-right ambiguity. So the new algorithm has better performance than the existing algorithms.