Using FIM-Capon to Improve Joint Detection Performance of UUV-Based Flank and Towed Arrays

For the flank and towed arrays mounted on an unmanned underwater vehicle (UUV), the detection performance of each of them is often insufficient. To solve the problem, the joint processing of the flank and towed arrays provided a potential way. However, the gap between the flank and towed arrays and the low input signal-to-noise ratios (SNR) of the two arrays will lead to degraded performance. In this paper, we combine the UUV-based flank and towed arrays together to form a single integrated array, and try to improve the detection performance of the integrated array. Toward this end, we apply the Capon beamformer with Fourier integral method (FIM-Capon) to the integrated array. Firstly, FIM is applied to the integrated array (i.e., the flank and towed arrays). Then, the Capon beamformer, based on the output of FIM, is used to improve the detection performance. In the propose method, FIM can fill the gap between the flank and towed arrays, improve the input SNR and extend the array aperture, which is much helpful for improving the performance of the Capon beamformer. As a result, FIM-Capon will show a better performance than other beamformer methods, and improve the joint detection performance of the UUV-based flank and towed arrays. Numerical simulations demonstrate the effectiveness of the proposed method.