高信噪比、高分辨宽测绘带成像

High Signal to Noise Ratio and High Resolution Wide Swath Imaging

针对传统高分辨和宽测绘带以及高信噪比和宽测绘带之间的矛盾,提出一种基于脉内扫描面阵合成孔径雷达(SAR)系统的二维空域联合处理算法实现高信噪比、高分辨宽测绘带成像。文中首先建立脉内扫描面阵SAR系统模型,该系统采用低脉冲重复频率(PRF)获得宽测绘带信息,同时利用脉内扫描方式获得高信噪比的回波信号。对于低PRF采样宽多普勒谱(对应方位高分辨)引起的多普勒模糊以及脉内扫描引起的距离模糊,提出一种二维空域联合处理算法解距离和多普勒模糊,并且详细地分析了地形高度变化对解模糊算法的影响。最后,通过仿真实验验证了本文算法的有效性。

With respect to the contradictions between high azimuth resolution and wide swath,as well as high azimuth resolution and high signal to noise ratio（SNR）,a two-dimensional（2D）spatial combination algorithm is presented to achieve high SNR,high resolution and wide swath imaging based on plane-array synthetic aperture radar（SAR）system with intrapulse scanning technique.First,the model of plane-array SAR system with intrapulse scanning technique is built.Low pulse repetition frequency（PRF）is used to acquire the information of wide swath,and intrapulse scanning technique is adopted to obtain echoes with high SNR.With respect to the Doppler ambiguities caused by low PRF sampling wide Doppler spectrum（corresponding to high azimuth resolution）and the range ambiguities caused by the intrapulse scanning technique,a 2D spatial combination algorithm is presented to solve the range ambiguities and Doppler ambiguities at the same time.Meanwhile the effect of the scene fluctuation on this algorithm is analyzed in detail.Finally,simulation results verify the effectiveness of the proposed algorithm.