I want to georefrence and process my meteosat-8 Indian ocean data coverage (MSG-1 IODC) in native format (.nat) using Envi5.3 , I tried with envi classic 5.3+IDL and Envi5.3 but I couldn't do that. I found an extension in Internet "ENVI MSG tools" and installed it. after that I could read my native format but when I used "GEOREFRENCE MSG" option in "Map" the coordination of my georefrenced map was incorrect, It seems that this extension has a problem with MSG-1 Indian ocean data coverage. what should I do? I would be very grateful if one anwer my question. Thanks.