Anti-Disturbance Initial Alignment Method Based on Quadratic Integral for Airborne Distributed POS

Airborne distributed position and orientation system (POS) is playing an important role in the high-resolution aerial survey and a remote sensing system. It is composed of a master inertial navigation system (INS), the global navigation satellite system, and several slave INSs. However, the high-frequency vibration disturbance of aircraft engine and the flexure deformation disturbance of lever arm could lead to serious initial alignment errors of slave INSs. In order to solve the problem, an anti-disturbance initial alignment method based on quadratic integral for airborne distributed POS is proposed. A coarse alignment based on quadratic integral in inertial frame is proposed to reduce the disturbances of high-frequency vibration and flexure deformation. Furthermore, the disturbance of flexure deformation is considered as the first-order Markov process, and is added into the fine transfer alignment model. The experimental results verified that the proposed method can effectively improve the initial alignment of the distributed POS, especially the azimuth precision of two slave INSs which are improved by 0.0260° and 0.0167°, respectively.