A Comparison of PCA and LBF Based Multireceiver SAS Imaging Algorithms

Multireceiver synthetic aperture sonar (SAS) is a useful tool to provide high-resolution images. The most important step lies in developments of multireceiver synthetic aperture image formation processors, which uses the sonar echoed signal as the input. The system transfer function is crucial in the development of signal processors. In order to use traditional imaging algorithms, the monostatic conversion transferring multireceiver SAS signal to monostatic SAS data is often conducted. A review and evaluation of imaging methods based on monostatic conversion is conducted in this article. The relationship of Phase center approximation (PCA) method and Loffeld’s bistatic formula (LBF) is firstly reformulated in theory. Considering facts that PCA and LBF methods are the approximation of exact system transfer function, the approximation error of both methods are firstly compared and evaluated by using the numerical system transfer function, which is considered to be the precise system transfer function. Since more approximations of PCA and LBF should be carried out to develop fast imaging algorithms, the actual phase error of both methods is compared and evaluated based on numerical system transfer function. Then, the imaging performance of both methods based on range migration algorithm (RMA) is further evaluated. At last, the relationships of both patent methods are comprehensively described.