Long-term Stability Analysis of Vertical Channel Damping and Kalman Filtering for Inertial Navigation System/Vertical Gauge

This paper deals with inertial navigation system (INS) aided by a vertical gauge (VG) for unmanned vehicles in two different schemes, vertical channel damping (VCD) and Kalman filter (KF). As the altitude error of standalone INS goes to diverge quickly, a VG can play a key role in an integrated navigation. A conventional technique to integrate INS with a VG is the VCD scheme which only corrects the vertical channel states by separating them from those of the horizontal channels. On the other hand, in this paper, it is shown that a KF scheme without separation of them can also reduce the horizontal position estimation errors as well by only using a VG. The navigation results of the two different schemes through numerical simulations are compared. Providing the simulation results on the both of correct and incorrect KF measurement error model, it shows the performance of KF scheme considerably depends on the model accuracy.