成像雷达干涉测量数据相关性与干旱—半干旱地区地表类型特征的关系

RELATIONSHIP BETWEEN COHERENCE OF SAR INTERFEROMETRY AND SURFACE FEATURE IN ACRID TO SEMI-ACRID AREA

利用欧洲资源卫星 1号和 2号获取的重轨干涉测量雷达数据 ,首先进行干涉测量数据相关性估测 ,并结合干涉测量数据的振幅信息 ,开展新疆喀什试验区地表土地类型的识别与分类 ,区分和识别出裸土、盐碱地、灌丛、裸岩 /戈壁、沼泽和水体 6类土地类型。最后通过对不同土地类型的后向散射特性和相关性的分析 。

At recent years, imaging radar interferometric technique with its all weather, day and night capabilities, can generate the digital elevation model (DEM) and monitor surface change using amplitude and phase information from radar signal. So it has become a potential tool to acquire more resource and environmental information. The repeat pass interferomety acquires two images by using one antenna for repeat passes over the same area at two different times. The two images can be used for further information extraction only while they have somewhat coherence. This paper presented the results of discrimination and classification of surface land types in Kashi test site, Xinjing of northwestern China using the repeat pass interferometric data, acquired by European Resource Satellite 1 and 2, based on the interferometric coherence estimation and amplitude intensity. Six types of land were discriminated and classified, including in bare soil, salina, bush, bare rock/gobi, marsh and water body. Then the backscatter and coherence characteristics of these land types were analyzed, and the relationship between coherence and surface features in acrid and semi acrid area was also discussed. Bare soil and dry salina have high coherence, but their backscatter coefficients are different. Bush has middle coherence, and the backscatter feature is similar to bare soil. Wet salina and bare rock/gobi have low coherence, and have the different backscatter coefficients. Marsh and water body have the lowest coherence, and their backscatter features are different.