Improving GPS/INS Signal Accuracy using Kalman Filter during GPS Outages

Abstract

The rapid development in the transportation systems, has made vehicle navigation and positioning an area of research. GPS system is the most widely acceptedsystemfor vehicle navigation and tracking. It is a system which is based on the satellites whichprovides us the altitude, velocity and the position at any location on the earth.GPS is  generally used along with INS (Inertial Navigation System) to achieve better accuracy. The integration of the two navigation systems (SINS/GPS) helps to improve the overall accuracy and the reliability of the navigation system and manages to give a better performance. The integrated system works fine, but when GPS signals are unavailable the performance is degraded.Also,there are certain scenarios when the GPS signal outage is observed, it maybe when the vehicle travels through tunnels, ruralareas, indoor areas and also in forest areas. So, a system is designed to process the information when the GPS signal is unavailable. The application of Kalman filter is in smoothing noisy data and provide estimates of parameters of interest. To obtain accurate , reliable and continuous signals at times when GPS signal is lost, a system is designed which uses an Extended Kalman Filter to find the GPS signals during the GPS/INS outages. Kalman filter ensures that a high accuracy is achieved. After the implementation, it is observed that the model gives a good performance.