Application of Kalman Filter algorithm in gravity-aided navigation system

To restrain the error of inertial navigation system (INS), gravity-aided navigation system is introduced. The principle of gravity-aided navigation system is expatiated. By using Kalman Filter, error correcting of inertial navigation system comes true. Extended Kalman Filter (EKF) model is derived, and a method of gravity filed linearization is given. Based on the analysis of the shortage of EKF, Unscented Kalman Filter (UKF) algorithm is established. UKF is a nonlinear filter algorithm. Simulation results proved that the methods of EKF and UKF can effectively depress the error of INS.