Estimation of direction of arrival for broadband signals based on single snapshot using horizontal arrays in the deep sea

Addressing the issue of small multipath azimuth differences and strong coherence for broadband targets using deep-sea horizontal arrays, a high-resolution compressive sensing direction of arrival (DOA) estimation method tailored for broadband coherent signals is proposed. This method first applies a Fourier transform to the received signals, then focuses each frequency component of the signals onto a reference frequency through spatial resampling, and finally employs compressive sensing for DOA estimation. Simulation experiments have shown that this method is capable of separating and estimating the arrival azimuths of multipath signals in deep-sea environments. Compared to traditional compressive sensing-based DOA estimation methods, this method demonstrates higher estimation accuracy, with a reduction in root mean square error by approximately 85%. Sea trial results show that the proposed method can separate and accurately estimate the characteristic sound rays in both the sound shadow zone and the direct sound zone. Compared to traditional compressive sensing DOA estimation, this method not only exhibits lower background interference but also achieves higher azimuth estimation accuracy.