An in situ inter-calibration for azimuth rotating gimbaled INS in mooring mode

In mooring mode, the technology of in situ calibration for azimuth rotating gimbaled inertial navigation system (ARGINS) is far from satisfying, due to its time-consuming and low navigation precision. In order to realize an accurate calibration in mooring mode, we utilize the redundancy of two ARGINS data, and take the difference between two navigation outputs as the relative reference benchmark. Then, an inter-calibration algorithm for accelerometer bias residual error and the relative platform-fixed errors between two ARGINS is proposed. With the proposed algorithm, the calibration can be fulfilled with all the apparatus of GINS in situ. The proposed algorithm can improve two ARGINS attitude accuracy in mooring mode without a turn table or other external measurement information. The proposed algorithm is verified and evaluated by real experiments. Mooring experimental results show that the attitude output consistency between two ARGINS can be reduced to 0.5 arc min.