(Data West Research Agency definition: see GIS glossary.) A least-squares computer software program run against a raw digitized data source map to produce a geographically true "X" and "Y" coordinate database referenced to any standard map system. Based on the locations of control monuments, a "best fit" is made to the source map's origin, rotation, scale, skew, and stretch. If the source map's systematic errors were small, an accurate "fit" will be made resulting in small residual errors. Also called rubber sheeting and coordinate rotation/translation.