DOA estimation based on compressive sensing with passive synthetic aperture

When the physical aperture of array is limited, the synthetic aperture is usually used to improve the spatial resolution of the underwater target azimuth estimation. However, due to the horizontal-longnitudinal coherence of the underwater signal, it is impossible to increase the resolving power by aperture extending unrestrictedly. A new DOA estimation method by using compressive sensing with passive synthetic aperture (PSA) is proposed to obtain the higher resolution. Firstly, the PSA technique is used to obtain a virtual aperture, on this basis, and then the compressive sensing is adopted to estimate the target azimuth. In the simulation experiments, the proposed method can distinguish two targets whose angle difference is only 2°, and it also have high probability of success estimation in low SNR. In the water tank experiments, the proposed method can clearly distinguish three adjacent targets which can not be distinguished by the PSA alone. This proposed method has great application value in the high resolution positioning of underwater vehicle with short array.