A numerical implementation of analytical transformation using map projection

This paper systemically elaborates map projection and map projective transformation. Based on these theories, it develops a GIS map projection software using Visual C++ as a platform. The software consists of two parts: analytical ordinal transformation and analytical athwart transformation. Analytical athwart transformation implements map projective transformation with coefficients obtained through numerical method, which is also the main idea of this paper. Map projective transformation process is illustrated with the examples of Mercator projection and conic projection. The system can be used alone or be integrated into other GIS systems to enhance their map projection function.