基于信号的环视SAR成像参数估计方法

Data-based Parameter Estimation Method for Circular-scanning SAR Imaging

环视合成孔径雷达(SAR)是一种新的雷达成像模式,其成像结果的图像质量与成像参数的精度密切相关,特别是雷达平台实际运动速度的不精确测量会严重影响图像质量。该文针对环视SAR成像模式的特点,提出了一种基于雷达回波信号的平台运动速度和天线扫描角度估计方法。该方法借鉴了多波束多普勒导航技术的基本思想,建立了新的数学模型和方程组表达式,并在实际处理中以最小二乘为准则实现了参数搜索和最佳逼近。仿真数据处理的结果表明,该方法能准确地实现上述参数估计,从而显著提高了环视SAR系统输出图像的质量。

The circular-scanning Synthetic Aperture Radar （SAR） is a novel working mode, and its image quality is closely related to the accuracy of the imaging parameters, particularly considering the inaccuracy of the real speed of motion. According to the characteristics of the circular-scanning mode, a novel data-based method for estimating the velocities of the radar platform and the scanning-angle of the radar antenna is proposed in this paper. By referring to the basic concept of the Doppler navigation technique, we first improve the mathematic model and formulations for the parameter estimation. The optimal parameter approximation based on the least square criterion is then realized for solving the equations derived from the data processing. The simulation results verify the validity of the proposed scheme.