A Novel Multireceiver SAS RD Processor
Xuebo Zhang, Peixuan Yang, Yanmei Wang, Wenyan Shen, Jiachong Yang, Junfeng Wang, Kun Ye, Mingzhang Zhou, Haixin Sun
Abstract
Classic multireceiver synthetic sonar (SAS) reconstruction algorithms relying upon Loffeld’s bistatic formula (LBF) should firstly utilize the data segmentation approach to remove the multireceiver deformation (MD) term. Usually, the small sub-block is required by traditional LBF based imaging algorithms to produce the high performance result. To address this issue, we describe a receiver-by-receiver based imaging algorithm. The presented method firstly reformulates the original LBF to range dependent and independent terms. Then, the image reconstruction receiver-by-receiver is carried out. The LBF reformulation and the quadratic expansion of range-dependent term needed by subsequent range-Doppler (RD) algorithm would generate approximation error corrected by data segmentation approach in frequency domain. After performing the range cell migration correction (RCMC) receiver-by-receiver, the signal in range-Doppler domain related to each receiver is coherently synthesized, and the azimuth offset is thereafter corrected. The focusing result would be produced when the azimuth inverse Fourier transform (IFT) is completed. On the basis of simulation and real data test experiments, conventional focusing approach with wide sub-block is seriously affected by ghost targets, which are successfully avoided by presented method with the same wide sub-block. It indicates that the presented method relaxes the requirement for the sub-block width.