Assessment approach for calculating transfer alignment accuracy of SINS on moving base

• IAD method for evaluating transfer alignment accuracy is put forward.
• 4 filtering and smoothing algorithms are analyzed and contrasted.
• Estimation mathematic model was built.
• Evaluation scheme of transfer alignment on moving base was designed.

This study aims to evaluate the accuracy of transfer alignment of SINS on moving base. To this end, index of alignment degree (IAD) was put forward to try out in the engineering application of transfer alignment accuracy evaluation and identification. The direct statistical formulas were inference as the estimation foundation and the evaluation scheme of transfer alignment on moving base was designed while the attitude error cannot be directly measured. The mathematical estimation model was built and the algorithms of fixed point smoothing (FPS), fixed interval smoothing (FIS), inverted sequence recursive estimation (ISRE) and Kalman filtering (KF) were discussed which adaptable in alignment accuracy evaluation. Depending on theoretical calculation and simulated analysis, it shows: IAD reflects not only the alignment time and alignment accuracy, but also the differences of maneuver scheme, which is suitable as an integrated evaluation index; Four algorithms can all be used to transfer alignment accuracy evaluation and identification, FIS is recommended in engineering practice; Generalized IAD should be calculated according to the tactical requirement.