摘要
由于传统TOPSAR具有均匀的天线扫描速度,在扫描范围较大的情况下,靠近图像边缘的目标被天线波束照射的时间较短,图像中心部分的目标照射时间较长,从而导致了TOPSAR图像分辨率不一致,针对上述问题提出一种非匀速扫描的TOPSAR成像方法,根据TOPSAR扫描几何模型得到图像分辨率与扫描速度的数学关系,通过控制天线的旋转角速度,使场景中方位向不同位置的点目标积累时间相同,从而保证了所得SAR图像具有相同的方位分辨率。仿真结果和分析表明,该方法有效地保证了TOPSAR图像分辨率的一致性。
In the case of wide target area, traditional TOPSAR scans target area with uniform angular velocity. However, the resolution of point target on the edge of scene would degrade due to the short dwelling time of antenna beam. While the point target in the center of scene owns higher resolution than the target on the edge of scene because of the long dwelling time. A novel method that antenna beam scans all the scene with non-uniform angular velocity is proposed in this paper. According to the geometry model of TOPSAR, accurate relation of target resolution with angular velocity is deduced in the paper. We can control the antenna beam scanning angular velocity real time to assure that all point targets in the scene keep uniform dwelling time. Then, the resolution of scene edge and center become uniform. The experimental results and analysis demonstrate the validity of the proposed method.
出处
《电视技术》
北大核心
2015年第21期23-27,共5页
Video Engineering
基金
航空基金项目(201101811004)
