DEVELOPMENT OF ERROR COMPENSATION METHOD AND ALGORITHM IN DEAD RECKONING FOR IMPROVING PRECISION OF GPS NAVIGATION

Abstract

Global Positioning System (GPS) is a network of 24 satellites which orbits around the earth. For decades, GPS receivers are used in navigation systems. GPS receivers requires minimum of 4 satellite visibility to derive location information and time information. Since the visibility of four satellitescould be affected by tall buildings, trees and bridges, its accuracy gets degraded when vehicles move in areas where tunnels or underground passages are present or in urban canyons. To improve the position accuracy of GPS, different systems like Assisted GPS and Differential GPS were introduced but they require network connectivity and more field equipment and infrastructures respectively. Under these circumstances, dead reckoning solution is preferred where present position is calculated from previously determined position and also with the knowledge of position dependent time varying parameters like acceleration, velocity etc. One way of accomplishing dead reckoning is by using inertial navigation system which uses Inertial Measurement Unit (IMU) consisting of accelerometers, gyroscopes and magnetometers. Based on the last known position from GPS,