What does DRG stand for in geographic information systems?

The acronym DRG stands for Digital Raster Graphic in the context of geographic information systems. A Digital Raster Graphic is a scanned image of a topographic map or other kind of map that is georeferenced, meaning it is aligned with spatial coordinate systems. This allows for the image to be overlaid and analyzed with other geographic data layers within a GIS environment. DRGs are essential for preserving historical cartographic data and for integrating it with contemporary GIS applications, enabling users to perform various spatial analyses and map visualizations.

This answer highlights the importance of DRGs in GIS, emphasizing their role in maintaining the integrity of existing maps while allowing for advanced geospatial analysis. Other interpretations of the acronym would not accurately reflect its established usage in the field of geographic information systems.