The basic ASTER Level 1B data sets are provided in the hierarchical data format (HDF). ENVI can directly open these data, but there are a few special processing steps you should perform on these files. ASTER products are handled a bit differently, as described briefly next.
Radiometric correction is a process that improves the quality and accuracy of remote sensing images by removing or reducing the effects of atmospheric, sensor, and illumination factors.
Atmospheric correction of the radiative transfer method involves simulating the relationship between the atmospheric parameters of the satellite synchronization and the true reflectivity of the surface by simulating the radiation transmission process between the atmospheric–surface remote sensor.