C.A. Brewer1, B.P. Buttenfield2, C. Frye3, J. Acosta1

1 - Pennsylvania State University, Dept. of Geography, University Park, PA, USA

2 - University of Colorado, Dept. of Geography, Boulder, CO, USA

3 - ESRI Inc., Redlands, California, USA


We present continued work on ScaleMaster, a tool that guides and describes multi-scale map design and combination of databases at widely ranging resolutions. This work complements multi-representation database (MRDB) research ongoing in Europe. We are using U.S. databases compiled at anchor scales of 1:5,000, 1:24,000, 1:100,000, and 1:250,000 to produce maps at all scales ranging from 1:5,000 to 1:1,000,000. These demonstration maps are produced using only selection, elimination, and symbol design changes. Relying on these changes to the display is a contrast with the geometry changes produced by generalization operations such as simplification and displacement. We have constructed approximately 20 maps designed for each of three map types: a topographic map set, thematic map set (with zoning and income foci), and operational map set (with an emergency response focus). Maps are produced at scales throughout the 1:5K to 1:1M range and we have detailed all changes in display that produce these designs. Designs at some scales combine data from a variety of anchor database resolutions.

Pilot work has shown that different map purposes have differently organized ScaleMaster diagrams. Topics suited to general reference uses, such as the topographic map set, have ScaleMaster diagrams that attenuate at smaller scales because fewer feature classes are selected and labeled, but the maps remain useful through a very wide range of scales. Maps with specific purposes are useful through a narrower range of scales and maintain a more consistent set of feature classes and symbol designs. The goal of the project is to guide workload balancing by combining changes in geometry and display to reduce overall workloads in map production. The project goals include assisting decision making on a minimum set of anchor database resolutions that need to be compiled for mapping agency needs. In addition, the project seeks to assist selection of a minimum set of resolutions for production of pre-computed generalizations. Accurate selection of intermediate Level of Detail (LoD) database resolutions will effectively reduce map making workloads throughout the range of map scales and purposes needed by a mapping agency.