摘要
二维频谱解析表达式是SAR系统频域成像算法的关键所在。针对难以直接求解星机双基地SAR系统驻定相位时间点的解析解的问题,该文提出对系统响应二维频谱的相位项在一个易于求得解析解的时间点做二阶泰勒展开并取近似;利用该系统两平台间运动速度、斜距差异显著的特点,来选取泰勒展开时间点,使其位于系统驻定相位时间点满足一定条件的邻域内,从而保证了近似相位的误差可忽略,由此获得较精确的近似二维频谱及其解析表达式。文中分别利用TerraSAR-X和PAMIR作为星载、机载平台,仿真成像场景内不同点目标近似二维频谱的相位误差,并利用近似二维频谱对点目标回波进行成像处理仿真,仿真结果验证了本文方法的有效性。
Two-dimensional spectrum＇s analytical expression is the basis of the frequency domain imaging algorithm for SAR system. A solution for the approximated two-dimensional spectrum＇s analytical expression of spaceborne/airborne hybrid BSAR is presented. To overcome the difficulty of resolving analytical solution for the system＇s stationary phase point, the two-dimensional spectrum＇s phase is two-order expanded around the point, which is not only in the neighborhood of the system＇s corresponding stationary phase point but also can be obtained analytically. Thus the spaceborne/alrborne hybrid BSAR system response＇s approximated spectrum is pretty close to the real one and can be expressed analytically. Taking TerraSAR-X as transmitter and PAMIR as receiver, the phase error caused by the approximation is simulated for different point targets in the image scene, and the simulated echo of point target is focused by the approximated two-dimensional spectrum. The simulation results demonstrate the validity of the proposed solution .
出处
《电子与信息学报》
EI
CSCD
北大核心
2008年第9期2073-2076,共4页
Journal of Electronics & Information Technology
关键词
星机双基地SAR
二维频谱
解析表达式
Spaceborne/airborne hybrid BSAR
Two-dimensional spectrum
Analytical expression
