Formal specification of geographic data processing requirements

This paper establishes a formal foundation for the specification of Geographic Data Processing (GDP) requirements. The emphasis is placed on modelling data and knowledge requirements rather than processing needs. A subset of first order logic is proposed as the principal means for constructing formalizations of the GDP requirements in a manner that is independent of the data representation. Requirements executability is achieved by selecting a subset of logic compatible with the inference mechanisms available in Prolog. GDP significant concepts such as time, space and accuracy have been added to the formalization without losing Prolog implementability or separation of concerns. Rules of reasoning about time, space and accuracy (based on positional, temporal and fuzzy logic) may be compactly stated in a subset of second order predicate calculus and may be easily modified to meet the particular needs of a specific application. Multiple views of the data and knowledge may coexist in the same formalization. The feasibility of the approach has been established with the aid of a tentative Prolog implementation of the formalism. The implementation also provides the means for graphical rendering of logical information on a high resolution color display.