hello everyone: I use the ENVI 4.0and IDL 6.0,but 1.when I want to use the IDL6.0-import hdf file to open the ASTER file,it can not open it .why is it?is not the hdf or hdfeos.but I can open it using the hdf explorer.or it's name is not correct?the name is pg-PR1B0000-2002042902_029_001.it is ASTER 1B. 2.if I write the program in c,can I link it to IDL6.0? if someone know this,please help me.thank you! hqh20000@263.net