Ground vehicles can navigate using signals from external navigation systems such as the Global Positioning System (GPS) (Figure ), or by using signals from internal devices such as a compass, an odometer, a gyroscope, an accelerometer, or a full-blown inertial navigation system (INS). In practice, the most reliable and accurate navigation is obtained by combining data from all available sources, including static databases such as a digitized map. This chapter will discuss many of these sources of navigation data, and methods for combining them
