基于三阶多项式傅里叶变换的SAR地面加速运动目标参数估计与成像

摘要

该文主要针对加速运动目标的参数估计及成像问题，推导了加速度目标的SAR回波频谱，分析了回波相位三次项估计和补偿对运动参数估计和SAR成像的必要性。提出一种利用Hough变换估计距离走动率和径向速度、相位补偿法校正距离徙动效应，并基于三阶多项式傅里叶变换(LPFT)对三次相位估计的新方法。利用Hough变换，在不明显增加计算量的前提下，达到加速运动目标的运动参数精确估计和精确聚焦成像的目的。最后通过仿真数据验证了该算法的有效性。%This paper aims at the issue of accelerating moving target parameter estimation and imaging. The SAR echo spectrum of target with acceleration is calculated, and the necessity of estimation and compensation of the three-order moving target echo phase to imaging and movement parameter estimation is analyzed. Then, a Novel algorithm is proposed to estimate range cell migration rate and range velocity by Hough transform, compensate the range cell migration by phase compensation, and estimate the three-order phase using three-order Local Polynomial Fourier Transform (LPFT). Using the parameter estimated by Hough transform, the movement parameters can be precisely estimated and image well focused without increasing the calculation significantly. Simulated data processing results are provided to demonstrate the effectiveness of the proposed algorithm.