Introduction

Abstract

In recent years positioning technology has become an important adjunct to modern life. In the past such technology was restricted to large professional applications such as the navigation of ships and aircraft or land surveying, However, with the advent of modern electronic devices such as smart phones, the ready availability of positioning information has meant that it becomes an important requirement to ordinary peoples daily activities, be it navigating in a car, finding a nearby restaurant, recording the location of a picture snapped on a smart phone, or tracking your daily run on your smart watch.