机载交轨稀疏阵列天线雷达的下视三维成像处理

摘要

该文研究了机载交轨稀疏阵列天线雷达的下视3维成像处理问题.将稀疏阵列天线布设在载机交轨向,采用频分正交信号实现多发多收以提高发射功率,利用多相位中心孔径综合原理将稀疏阵换成满阵,采用与空间位置相关的匹配滤波器使不同子带信号孔径综合后相位中心的空间位置相同,进一步将子带信号合成宽带信号以提高距离分辨率实现下视3维成像.为了扩大观测幅宽,提出将ScanSAR模式与SweepSAR模式相结合的扫描方式,以降低雷达系统的脉冲重复频率.分析了机载交轨稀疏阵列天线雷达的系统参数,通过仿真验证了该文方法的有效性.%Airborne cross-track sparse array radar system for downward-looking three-dimensional (3D) imaging is investigated. The sparse array is distributed along the cross-track direction. To improve the transmitting power, orthogonal frequency division signals are used for Multiple-Input and Multiple-Output (MIMO). The multiple phase center aperture synthesis principle is used to make the sparse array coincident with a full array. The phase centers of different sub-band signals will be in the same position by using the matched filter related with spatial location. The broadband signal is obtained by combining the sub-band signals to improve the range resolution. And the downward-looking 3D image is achieved. To expand the observation swaths, a kind of scanning mode which combines ScanSAR mode and SweepSAR mode is proposed, which can reduce the Pulse Repetition Frequency (PRF). System parameters of the airborne cross-track sparse array radar are analyzed. The simulation results indicate the feasibility of the proposed method.