为了研究在双站合成孔径雷达中直达波对成像分辨率的影响, 提出基于后向投影的直达波消除高分辨率成像算法.首先, 分析直达波的波达时间, 获取收发端的距离信息及直达波的空间电磁分布;其次, 分析电磁波历经多目标的成像空间后的接收信号 (包含目标的反射回波及直达波);最后, 分析此时空间的成像谱, 并减去先验得到的直达波空间电磁分布, 从而提高成像分辨率.研究表明:所提方法, 不仅得到目标清晰的像, 还适应不同接收器排布的情况, 提高双站SAR系统成像分辨率的同时, 还增加系统的应用灵活性.并在噪声中表现出良好的分辨率特性.%A high-resolution imaging algorithm based on back projection (BP) is proposed in this paper for studying the influence of forward wave in bistatic SAR application. Firstly, the distances between transceivers, and electromagnetic distribution generated by forward wave can be obtained by analyzing the time of arrival (TOA) of the forward wave. Secondly, the electromagnetic waves which are from transmitters will go through the whole imaging area contained multiple targets, and then are recorded by receivers. Here, the recorded signals contain reflected wave generated by multiple targets and forward wave. Finally, the whole imaging results will subtract the electromagnetic distribution produced by forward wave, which leads to an improved imaging resolution. These results show that the clean imaging map of multiple targets can be got by using the proposed method which is also able to be used in different receivers' arrangements. Moreover, the proposed method does not only promote the imaging resolution but also enhances the application flexibility of bistatic SAR. It is worth mention that the performance is also good even in a noisy environment.
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