ENVI's 3D SurfaceView tool can overlay an image from an ENVI display onto a surface defined by a DEM of the same area. So, to overlay both your ASTER image and your geological map onto the surface, you would need to put those in the same display somehow. Which is possible, depending on what form your map is in. If it is a vector layer (or layers), then you could overlay it onto a display of your ASTER image. Then when you generate your 3D SurfaceView from that display, you can choose Options > Import Vectors to get the vectors to show up as well as the image. - Peg

Hi Peg Thanks for your reply. My geological layer is as ArcMap shapefile. That means, I need to open first my ASTER image by File I am not sure how do I overlay my vector layer on it. Could you please guide me on that? I tried to follow steps below 1)first I went into the image window (the window where my ASTER image is open) 2) overlay 3)Then after it asks me to convert my ArcMap shapefile into .evf file 4) I am not sure what to do after this. How do I overlay my vector layer on the imagery? Please help Regards Yask

It sounds like you are halfway there. When ENVI opens a shapefile, it creates a new vector file that is in ENVI's own vector format (EVF). It's just faster for ENVI to work with data in that format, rather than in the shapefile format. So, go ahead and let it create the EVF file that it wants to make when you are opening a shapefile. Your original shapefile will not be affected. When ENVI is finished creating the EVF file from your shapefile, it will then overlay it onto the image in the display. - Peg