On lever-arm effect compensation for polar Transfer Alignment

In practical application, master and slave strapdown inertial navigation system (SINS) are not set in same location. This cause that the two specific forces measured respectively by the master and slave SINS are different. Existing polar Transfer Alignment (TA) algorithms neglect the lever-arm effect caused by the different measured specific forces. Therefore, the lever-arm effect will decrease the accuracy of these algorithms. In this paper, a TA algorithm considering lever-arm effect compensation is proposed. Based on “velocity plus attitude” matching method and grid frames, a Kalman Filter (KF) is used to estimate the misalignment angles in polar region. The lever-arm effect is also compensated to improve the TA accuracy. Simulation results have demonstrated that the TA algorithm proposed in this paper is effective in achieving the precise TA with lever-arm effect in the polar region.