1 - Introduction

Summary

Location is becoming an important and integral part of our everyday lives, spurred on by the widespread, almost ubiquitous, availability of GPS (Global Positioning by Satellite) technology in everyday consumer devices such as car navigation systems, mobile phones and cameras, and the increasing adoption of inertial sensors, particularly accelerometers and magnetometers in everyday products. In order to set the context, this book first looks at coordinate systems and what is meant by position or location and how to describe this information [Chapter 2].

Because of the importance of GPS, the next topic covered is global navigation satellite systems (GNSS) [Chapter 3]. The ability to determine the precise location of a device anywhere in the world is in turn leading to the emergence of many different Location-Based Services promoted by leading global companies such as Google with Google Maps and Latitude, Nokia, Microsoft, AOL and community initiatives such as OpenStreetMap.

However, despite the hype surrounding GPS it is not the only positioning technology available and indeed there are many applications for which it doesn’t offer the required capability or performance. This book is intended to give a clear understanding of the different options available for locating and positioning systems with an emphasis on their real-world capabilities and applications. The next chapter [Chapter 4] covers the most important methods for determining position using radio signals, then Chapter 5 covers inertial navigation techniques and Chapter 6 looks at other methods of locating and positioning things. Chapter 7 deals with accuracy and performance and what they mean, as well as some of the fundamental techniques relating to location and position. Of course things never go entirely as planned, so Chapter 8 considers errors and failures and how to deal with them.