A file that contains the coordinates of specific points, termed control points, in two different reference systems. Normally the first set of coordinates corresponds to the locations in an arbitrary plane reference system (non-georeferenced), while the second set of coordinates corresponds to the same locations in the desired georeferencing system. The coordinates in the correspondence file are used by the GIS software IDRISI for Windows module RESAMPLE to create a function with which to map the entire image to the desired georeferencing system
