Introduction

This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book outlines several themes that describe the common challenges that people face when working with projections. It examines two mathematical threads that are relevant to people who work with projections: ellipsoidal versus sphere Earth models and projection parameters. The book explores map projections and their influence on data. It provides a specific overview of the symbolization method, the main visual analysis tasks associated with reading and interpreting data represented by that method, and how projection characteristics and parameters can be adjusted to create a better map. The book focuses on special types of maps such as heatmaps, spatial bin maps, and special map use tasks such as measuring distances and directions on maps. It discusses map projection resources that are available through the web.