合成孔径声呐时延估计误差校正改进算法

由相位解缠错误造成的时延估计误差会严重降低合成孔径声呐时延估计的精度。现有的时延估计误差校正算法采用二次函数作为时延的拟合模型,该模型在距离向近端和远端处不符合时延空变规律,拟合误差较大且无法估计载体的横荡和升沉运动。针对该问题,文章提出一种改进的时延估计误差校正算法,利用时延的距离空变函数代替二次函数作为拟合模型。数值仿真和实验结果表明,相较于参考算法,改进算法校正时延估计误差的效果更好、速度更快,同时还能准确地估计载体的横荡和升沉运动。运动补偿结果显示了改进算法能较好地提升成像质量。

Improved algorithm for correcting time delay estimation errors of synthetic aperture sonar

Time delay estimation errors caused by phase wrap errors in time delay estimation seriously reduce the accuracy of time delay estimation of synthetic aperture sonar. The existing algorithm of correcting time delay estimation errors uses the quadratic function as the time delay fitting model, which does not conform to the rangevarying nature of time delays and has a large fitting error at the near range and far range, and cannot estimate the sway and heave of the vehicle. In this paper, an improved algorithm of correcting time delay estimation errors is proposed,and the range-varying function of time delay is used as the fitting model instead of the quadratic function. The numerical simulation and experimental results show that the proposed algorithm has better performance and lower computational burden in correcting the time delay estimation errors, and can also accurately estimate the sway and heave of the vehicle, compared with the existing reference algorithm. The results of motion compensation show that the improved algorithm can improve the imaging quality.