星载合成孔径雷达成像处理

IMAGING PROCESSING FOR SPACEBORNE SYNTHETIC APERTURE RADAR

合成孔经雷达(Synthetic Aperture Radar,SAR)是当今微波遥感领域的研究热点,其全天候、全天时、高分辨率以及穿透地表等特点使其具备其他传感器不可比拟的优势,因此得到了极其广泛的应用。成像处理是SAR技术的核心部分。分析了星载SAR点目标回波信号模型和几种常用的星载SAR数字成像处理算法。以距离-多普勒算法为例,阐述了距离压缩和方位压缩的实质,详细讨论了多普勒参数估计、距离徙动校正和斑点噪声的去除等几个关键的问题。采用ERS-1卫星数据做了成像实验,并对SAR成像技术加以总结。

Synthetic Aperture Radar （SAR）is currently a hot research topic in the field of technique of Microwave Remote Sensing. Compared with the other sensors, SAR possesses many incomparable advantages such as the capability to work at all-time and under all weather, high spatial resolution and strong penetrability through the ground surface. Thus, it has acquired widespread applications. Imaging processing is the core part of SAR technique. This paper first analyzes the echoes signal model of point target and several commonly used SAR imaging algorithms. And then, using Range-Doppler algorithm as an example, this paper illustrates the essential of range compressing and azimuth compressing, discusses in detail the key problems such as Doppler parameters estimation, range migration correction and speckle noise elimination etc. Finally, this paper gives an imaging example using ERS-1/SAR raw data, followed by a simple summary of the SAR imaging technique.