20世纪以来,资源、环境、灾害和国家安全等问题已成为人类社会发展中的主要问题。空间对地观测是解决这些问题的重要手段之一,越来越受到人们的关注。空间对地观测有多种手段,其中,合成孔径雷达(synthetic aperture radar,SAR)因其特殊的对地观测性能而受到广泛的重视。合成孔径雷达是一种工作在微波波段的主动式遥感器。它在灾害监测、坏境监测、海洋监测、资源勘测、农作物估产、森林调查、测绘,尤其是军事等方面的应用具有独特的优势,是其它遥感手段所不能替代的。 Since the 20th century, the problems of resources, environment, disasters and national security have become the major problems in the development of human society. Space-to-Earth observation is one of the important means to solve these problems, and has drawn more and more people’s attention. There are many methods for space-to-Earth observation, in which synthetic aperture radar (SAR) is widely regarded for its special earth observation performance. Synthetic Aperture Radar is a kind of active remote sensor working in the microwave band. It has unique advantages in disaster monitoring, environmental monitoring, marine monitoring, resource exploration, crop estimation, forest investigation, surveying and mapping, especially military, which can not be replaced by other remote sensing methods.