Self-calibration of laser gyro g-dependent bias for dual-axis rotational inertial navigation system

Improved position precision for a dual-axis rotational inertial navigation system is gotten after calibrating the gyro's g-dependent bias. By experiencing four more positions with tilt attitudes than conventional six-position method, not only constant biases, scale factor errors and misalignment errors, but also g-dependent biases can be calibrated. Static experiments show that latitude error and longitude error are remained within a small range over time. Compared with the traditional six-position method, the accuracy of longitude is improved about one time, and the divergence speed of longitude error becomes slow obviously. Using this self-calibration method, the accuracy of system is improved by more than 50% in static state.