工程可实现的多接收阵SAS精确逐点成像算法

Accurate back projection imaging algorithm for multi-receiver SAS in engineering application

为了解决传统基于截断插值方式的多接收阵合成孔径声纳逐点成像算法所导致的插值误差和图像相位信息畸变的问题,根据时延和频移的对应关系,提出了一种基于频移的逐点成像算法。该方法针对图像中的每一个像素,通过频移对其考虑"停-走-停"影响的精确时延史进行校正,从而将理论上精确的逐点成像算法拓展到实际工程应用中。通过仿真实验和实测数据对所提方法的有效性进行了验证,结果表明:相对传统基于截断方式的逐点成像方法,该方法可以避免插值误差,有利于后期干涉信号的处理。

In order to deal with the interpolation error and the distortion of phase information that are caused by the back projection （BP） algorithm for multi-receiver synthetic aperture sonar （SAS） based on the conventional truncated interpolation, this paper proposes a BP algorithm based on frequency shift according to the corresponding relationship between frequency shift and time delay. The algo- rithm is used to calibrate the accurate time-delay process under the ＂stop-and-hop＂ influence through frequency shift as far as each pixel in the image is concerned thus applying the theoretically accurate BP imaging algorithm to practical engineering. The simulations and measured data verify that compared with the conventional truncated-interpolation-based BP algorithm, the proposed method is able to avoid the interpolation error and improve the interferometric SAS signal processing results.