A COM-based expert system for selecting the suitable map projection in ArcGIS

A map projection is a systematic rendering of locations from the curved earth surface onto a flat map surface. It is impossible to make spherical maps into perfectly flat papers without some distortion. There are many projections, each with its own advantages and disadvantages. No single projection can maintain all of the important spatial variables such as shape, area, direction, and distance. A successful Geographic Information System (GIS) depends in large part on using map projections correctly, and a person's skills in managing and converting projections can dictate the value of a database. GIS software packages such as ArcGIS provides GIS analyst with many projections from which the analyst must choose the one suitable for his project. Map projection selection is a complex process involving an evaluation of map projection alternatives based on a set of characteristics that describe these projections and the types of analysis to be performed. This paper presents a prototype expert system for selecting the suitable map projection. The component object model (COM) technology is used in designing and integrating the prototype expert system with ArcGIS to achieve software interoperability.