Hi my dear friends, I tried many times to use FLAASH atmospheric correction on ASTER L1B radiance at sensor imagery data, I followed ENVI 4.8 tutorial step by tep: 1- Opening hdf file, rotate the scene to North, layerstacking VNIR and SWIR bands, change the layers interleave from BSQ to BIL; all data are in floatpoint format. 2- launching FLAASH and input the layer stack, output, output directrory and root name. 3- Other parameters are as follow: Scene Center (26.576913, 33.522527), Sensor type (ASTER), Sensor Altitude (705), Ground elevation (0.5 km),Pixel size (30m), Flight date (Oct,07,2007), Flight time (08:36:11), Atmospheric model (Tropical), Aerosol model (no aerosol), Aerosol retreival (none), Initial visibility (40 km), Water column multiplier (1) I got the following strange result: Basic Stats Min Max Mean Stdev Band 1 10022 31733 21659.327332 3112.752079 Band 2 -32768 32767 18565.863712 17028.841048 Band 3 -32768 32767 9294.338018 25513.794746 Band 4 -32768 32767 -3449.131618 27240.437507 Band 5 -32538 32657 6901.990400 27670.827593 Band 6 -32575 32637 8210.694485 26659.883219 Band 7 -32504 32684 5053.513011 27116.821587 Band 8 -32533 32640 3907.706868 26745.511909 Band 9 -32492 32456 -19378.138755 11149.961307 I hope you can help me in my target: converting ASTER L1B radiance at sensor to surface reflectance data (with values ranging between 0 to All my kind regards to all