A Fast Alignment Method for Aircraft Land-Based Takeoff

Both speed and accuracy are important indexes for initial alignment of inertial navigation system (INS), so rapid and high precision transfer alignment has been widely researched in the past decade. This paper analyzes aircraft's requirements for initial alignment before taking off in modern warfare. A new alignment method is proposed combining optical collimation and transfer alignment to overcome the disadvantages of limited maneuver and poor observable degree in aircraft's initial alignment. A new scheme of transfer alignment is presented, and the optical azimuth transitive relation between SINS (airborne INS) and MINS (master inertial navigation systems) is derived. Both angular rate plus acceleration matching model and relative azimuth obtained by optical collimation are fed into Kalman filter to estimate the installation angle of two INSs. Simulation results show that the new ground alignment method has fast convergence speed and high alignment accuracy to meet the requirements of modern aircraft's initial alignment.