The National Map


	All data that are spatially referenced make up the universe of geographic information. The universe includes socioeconomic data produced by the U.S. Bureau of the Census, crime statistics prepared by local law enforcement authorities, and zip code-based market penetration statistics compiled by advertising agencies. Within this universe, base geographic information provides the spatial foundation of commonly-needed information to which all other geographic data can be referenced.

	The Federal Geographic Data Committee (and many other organizations, such as the Mapping Science Committee of the National Academy of Sciences, the National States Geographic Information Council and the National Association of Counties) advocates the development of the National Spatial Data Infrastructure, or NSDI, to develop policies, standards, and procedures for organizations to cooperatively produce and share base geographic data. The NSDI framework data concept establishes a collaborative effort in which commonly needed data themes are developed, maintained, and integrated by public and private organizations. The framework categories include orthoimagery, elevation and bathymetry, hydrography, transportation, government units, geodetic control, and cadastral data. Sharing framework data helps to reduce operating costs and to improve service and decision making.