Rapid transfer alignment method based on inertial reference frame

Novel transfer alignment methods which take inertial frame as reference are investigated. The dynamic error models of transfer alignment in computed inertial frame and computed body frame are derived respectively, and the corresponding velocity plus attitude measurement equations are presented. In the above mentioned models, the direction cosine matrix of slave INS is described as the product of three transformation matrices by using chain rules, in which two matrices can be accurately computed through the alignment time and position information provided by the master INS. The remaining matrix is computed by utilizing the slave INS gyro outputs, and its errors are compensated through transfer alignment. The swaying experiments are made to verify the efficiencies of the proposed methods, and the results show that the alignment precisions of the two methods are both within 4'(1sigma;). Compared with conventional navigation frame based transfer alignment methods, the proposed alignment methods directly locate the attitude errors to the inertial frames, and thus the algorithms are easier.