INS Aiding by Combining Radar Altimeter and Seeker Measurements

Abstract

INS is aided by GPS for most of the missile applications. However, GPS blockage can occur, especially in combat areas. Without aid, INS errors will diverge. This paper proposes a novel methodology to improve the INS solution by using two extra measurements from a seeker and radar altimeter. Seekers are usually used at the final stage of the flight to measure the line-of-sight (LOS) angle and/or LOS rates. The radar altimeter provides the distance between the missile and the ground. In this study, seeker’s measurements, during the midcourse, and radar altimeter measurements are fused with the INS by using Extended Kalman Filter. The main advantage of the proposed methodology is that the position of the landmark is not required if the ground over which the missile flying is in the same level. Simulation results demonstrate the effectiveness of the proposed methodology.