LBF-Based CS Algorithm for Multireceiver SAS

The traditional imaging algorithm of multireceiver synthetic aperture sonar (SAS) based on Loffeld's bistatic formula (LBF) suffers from a tradeoff between focusing performance and efficiency due to the spatial variance of LBF. To improve the performance and efficiency, we develop a chirp scaling (CS) algorithm based on the reformulated LBF, which includes the range-variant and range-invariant terms. The phase error caused by LBF reformulation and range-invariant term is first compensated. Since the range-variant term used for the design of the CS algorithm is weighted by a factor, all filter functions of CS algorithm are newly deduced. Based on these improvements, the subblock width is allowed to be enlarged. Consequently, both the efficiency and performance are improved. Numerical results show that the ghost suppression performance of our method is improved nearly 10 dB compared to the traditional method. Besides, our method is more time-saving than the traditional method.