Passive direction-of-arrival estimation under high noise and strong interference condition for volumetric array

To enhance the passive direction-of-arrival (DOA) estimation performance of a volumetric array in high noise and strong interference background, a new DOA estimation method based on Fourier integral method (FIM) and inverse beamforming (IBF) is proposed. This method combines the two methods and thus obtains the interference cancelling capability of IBF and the noise suppression ability of FIM simultaneously. Furthermore, the proposed method is generalized to be feasible for arbitrary volumetric array and also achieves the same robustness as the conventional beamforming (CBF). With theoretical analysis and computer simulations, it is shown that with the proposed method, the volumetric array can obtain better DOA estimation results in low signal-to-ratio (SNR) condition as well as in the presence of interferences, when compared to the conventional CBF method.