Do Basic Tools>Resize Data, select your file and subset the bands you want to resize, then enter 0.5 for the x and y factors (to increase your pixel size by 2x). Choose a resampling scheme, either nearest neighbor or pixel aggregate. Alternatively, do Basic Tools>Layer Stacking. Basically does the same thing, but more flexible in terms of multiple projections, overlapping files, etc. Things you don't have to worry about with a common ASTER dataset. Chris