Lithological discrimination using hyperspectral remote sensing

Airborne Imaging Spectrometer data were acquired over zhangjiakou area in May 1997. To identify, different types of rocks of the area by using the images, visible and near infrared reflectance spectra of main types of rocks in the area are analyzed. Based on spectral features of rocks, some spectral indexes and bands be extracted to combine different color-composite images for mapping lothology. Some keys for lithological discrimination are built according to the spectral performances of images. Geological units are identified and mapped at 1:50000 scale. Comparing the results with previous geological map, modifications have been done about the boundaries and attributes of some geological units, and some new geological contents have been added into the geological map. Our results demonstrate that imaging spectrometer images contain richer lithological information than the images acquired by other remote sensors, and can discern subtle spectral differences between different rocks which is difficult to do by using TM images or infrared photograph etc. It is proved that imaging spectrometer data are effective and efficient in mapping geological unit at larger scale.