The spatial referencing deals with positioning and reference surface for mapping with include: Map Projection Systems, Coordinate Reference Systems and Coordinate Transformations. Satellite Based Positioning will be added because of its increasing importance in positional, mapping and navigation applications.

Reference Surface for Mapping

Ideally, reference surface for mapping is either curved for large area or plane for small area. Any area beyond length or breath of 1km is considered large, and may suffer from errors due to earth’s curvature. The earth is curved not flat, and transferring it into plane sheen of peper calls for appropriate map projection system, which is discussed below.