I recently discovered the raster library in R. With that library one can define a raster's coordinate reference system (crs) or projection. For example, to set the projection as NAD83 UTM 10N:
crs(raster) <- CRS(+init=EPSG:26910')
I wrote that raster to file and imported into ArcMap, but Arc said that the file was missing a spatial reference system.
In general, is it possible for an ASCII file to contain/define its CRS or projection? If so, can that be done with R's raster library or with ArcMap?