Polar moving base alignment for strapdown inertial navigation system

The traditional alignment method with Kalman filter is available in the low and middle latitude region, but not available in the polar region. For this issue, we propose the Kalman filter alignment under inertial frame as a solution. Firstly, the inertial frame is chosen to play the role of the alignment frame. The error model of a strapdown inertial navigation system which is applicable to the polar region alignment is derived under the inertial frame. And the misalignment angle equation and the velocity error equation are included in the error model of the navigation system. In this paper, the velocity error is used as the measurement information and the discrete Kalman filter is obtained on the basis of the alignment error model. Secondly, simulations are implemented to evaluate the feasibility of the proposed alignment algorithm in polar regions, compared with the traditional alignment method with Kalman filter. Moreover, the performances of the proposed algorithm under different speeds and accelerations are specially analyzed in order to provide theoretical basis for practical applications.