ABSTRACT
This chapter focuses on the key concept of map projection. The sequence of mathematical operations which leads to preparation of maps is explained through a sequence diagram. The important map transformations or map projections and their characteristics are explained. Some of the important applications of map projections are tabulated along with their properties. The classification of map projections from different mathematical perspectives and cartographic aspects is given. This chapter deals with the basic concepts of map projection and answers generic queries such as ‘What is map projection?’, ‘Why is map projection required?’, ‘Why there are so many projections devised?’, ‘Which map projections are suitable for a particular application?’ etc. How map projections are designed and developed for different regions of the Earth’s surface is explained. Classification of different map projections using different development surfaces, perspective positions and positions of tangent surface is explained. The categorization of map projections under different categories such as development surface, usage and characteristics is discussed. The mathematical formulae for forward and reverse map projections are derived ab initio. The chapter ends with a discussion on how to choose a map projection for a specific purpose and for a specific region of the world. All the concepts introduced here are supplemented by illustrations and key notes.
