Initial alignment of strap down inertial navigation system using Kalman filter

Initial alignment technology is one of the most important technologies for strapdown inertial navigation system (SINS). The accuracy of initial alignment influences the SINS´s navigation accuracy directly. In this work, the analysis of strap down inertial navigation system´s initial alignment is approach from a statistic point of view. Liner error models are presented and discussed, the observability of these models is discussed, and a Kalman filter is designed to estimate the states of error models. It is shown that not all those states are observable, and those states which are observable are different in rate of convergence.