机载UWB SAR实时图像帧几何形变分析与校正

Analysis and Correction of Geometric Distortion of Airborne UWB SAR real-time image frame

SAR实时侦察要求处理器实时输出预定成像区域的连续图像,但是机载UWB SAR数据分帧处理和实时运动补偿使得输出的实时图像帧之间产生错位和间断,影响图像帧的实时拼接。本文从机载UWB SAR实时处理结构和运动补偿入手,定量分析了参考航迹选择与图像帧几何形变量的关系,提出了一种实时校正机载UWB SAR图像帧几何形变的方法,然后分析了其校正误差。通过点目标仿真验证了分析结果的正确性,并给出了某机载UWB SAR实测数据几何形变校正前后相邻图像帧的拼接结果。

It is needed for the SAR processor to produce continuous image of the pre-scheduled mapping region in a real-time reconnaissance system,but the discontinuous and seams exist between adjacent image frames of airborne UWB SAR,which comes of datadivision processing method and real-time motion compensation,will greatly influence the precision of image frame mosaicing.Based on the discussion of real-time processing structures and motion compensation,a quantitative relationship between the conference track selection and geometric distortion is analyzed,and then a real-time geometric distortion correction procedure is put forward with the analysis and of the correction error.In the end,the simulation result of point targets is used to testify the correctness of the former analysis and correction procedure,and a mosaicing example of two adjacent airborne UWB SAR image frames before and after geometric distortion correction procedure is present in the final.