Ian Heywood, Graham Smith, Bruce Carlisle and Gavin Jordan
For centuries, geographers have found fascination in where things are in relation to each other. This obsession has manifested itself in the geographer’s desire to map everything and more recently (within the last century) to seek out and understand spatial relationships both in and between human and physical systems. Knowing where something is located in both space and time is therefore a prerequisite for almost all geographical research. Traditionally, geographers have used numerous techniques to determine both the relative and actual location of spatial phenomena. These have ranged from the very accurate and precise techniques of the surveyor to the more general methods of the social scientist. Recently, however, a new technique for locating spatial phenomena has found particular favour with geographers. This is the use of a satellite navigation system or global positioning system (GPS). These portable locational devices can be mounted on a vehicle, carried in a backpack or held in the hand and used to record location at almost any point on the Earth’s surface (Plate 43.1). Location information is obtained literally at the push of a button, with accuracy ranging from 150 m to within a few millimetres, depending upon the quality and number of receivers used and whether a military or civilian version of the system is accessed. Originally designed for real-time navigation purposes, all GPS receivers will store collected coordinates and associated information in their internal memory
Plate 43.1 GPS in the field.