机载平行等速双基SAR的极坐标格式成像算法

摘要

The bistatic synthetic aperture radar (SAR) refers to the SAR system whose transmitter and receiver work in a same orientation and equal velocity. It is called the azimuth-invariant bistatic synthetic aperture radar (SAR). The polar format algorithm (PFA) suitable for single base SAR imaging was improved to make it applied to the bistatic SAR imaging. Because the transmitter and receiver of the system are mounted in two different places, the slope-distance geometrical relation of the echo signal on the transmitting and receiving planes is complicated For the subsequent 2-D interpolation operation, a new geometrical model was established to describe the slope-distance relation on the transmitting and receiving planes. The new algorithm is easy as the conventional PFA to operate and implemente. The proposed approach was verified by the imaging processing of the simulation data.%平行等速双基SAR是指收发平台速度大小和方向均相同的双基SAR系统,该构型具有广阔的应用前景.在此将传统适用于单基地SAR成像的极坐标格式算法(PFA)加以改进,使之适用于平行等速双基SAR成像处理.由于收发异置,回波信号在接收平面和发射平面的斜距几何关系比较复杂.为了便于后续的二维插值操作,用一个新的几何模型来描述收发平面上斜距的关系.该算法具有传统PFA算法的操作简单,易于实现的特点.最后通过仿真数据的成像处理对该方法进行了验证.