SINS/CNS integration algorithm and simulations for extended time flights using linearized Kalman filtering

A robust integration algorithm for Strapdown Inertial Navigation System/Celestial Navigation System (SINS/CNS) is designed and investigated in this paper. The main objective of the developed integration scheme is the estimation and correction of unacceptable SINS' errors in long time navigation missions. A Narrow Field of View (NFOV) star tracker is used as a CNS aid in this study. A mathematical model is designed to estimate the platform misalignment angles and transformations of different frames are exercised. Linearized Kalman Filter (LKF), with a modified measurement model, encompassing the position errors, is proposed for fusing the data of SINS and CNS. Finally, simulation results are produced to show the integrity and validity of the integration algorithm for estimation and correction of the SINS errors in extended time flights.