S. Spahlinger

U.S. Census Bureau, Geography Division, Washington DC, USA


The U. S. Census Bureau requires paper maps and electronic map files to support the 2010 Decennial Census. Depending on the census operation, maps perform a variety of functions such as navigation (orientation), display of assignment areas for census takers; recording feature, boundary, and address updates to a spatial database; and relating census geography to statistical data.

The Census Bureau designs and produces millions of unique paper maps to support approximately thirty different census operations. Many operations are short term and a few involve over 100,000 temporary enumerators. A compressed operational schedule, coupled with high volume map production, requires a non-interactive mapping process. In this environment, a computer performs all cartographic functions. To meet these requirements, the mapping system employs cartographic decisions such as maximizing scale, minimizing numbers of sheets and their size, provides operation-specific content, and makes these decisions based on geographic entities such as a place.

In order to create a mapping system with such features, the Census Bureau conducted research and tested several commercial software packages. The Census Bureau discovered that spatial database design and Geographic Information Systems (GIS) software had advanced to support more complex spatial functions. Many GIS companies now use third-party commercial databases, and focus on improving their analysis and presentation tools. During their research, cartographers tested commercial software packages using census requirements and concluded that no single commercial software solution met all of the agencys needs. As a result, the Census Bureau plans to integrate different tools into one unified mapping system. The approach utilizes commercial software for geospatial database and analysis functions, text placement, and file conversion. Census cartographer-developed software complements commercial software and binds components together into a single mapping system.

In its customized mapping system, the Census Bureau employs automated computer algorithms that perform traditional cartographic functions such as scale determination, feature density assessment, inset area identification, map sheet layout configuration, text placement, integrated quality control, parameter driven symbolization, and specifically formatted output. This paper describes Census Bureau mapping goals, the rationale for the current approach, a description of the map production methodology, and anticipated issues associated with a comprehensive large mapping process.