INS error modification method based on pseudo line-of-sights intersection for cruise missile

In absence of other navigation systems, cruise missile inertial navigation system (INS) error cumulates continuously with time. To solve this problem, a novel INS error modification method was proposed based on continuous observation to single known feature target without the need of distance information. According to the relative relation between cruise missile and feature target, the INS error modification problem was transferred into the problem of multiple pseudo feature targets locating cruise missile cooperatively by using the pseudo line-of-sights intersection method. Then the cruise missile biased position was estimated by the least squares algorithm. Treating the biased position and atmosphere system information as the observation, unbiased estimation of cruise missile position and velocity were realized with application of Kalman filter which can simultaneously estimate state and system error with direct feedthrough. Simulation results show that this method can modify INS position error and velocity error effectively.