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.