Inertial navigation system positioning assisted by star sensor

The Star Sensor can be used to assist the inertial navigation system (INS) for navigation and positioning, restraining the accumulated error caused by the inertial components. During the integrated navigation process, the Star Sensor is installed above the INS, generated installation errors between the INS body coordinate system and the Star Sensor body coordinate system. In order to increase the system accuracy, a new gyro error model is established in this paper which taken full account of various error factors. The gyro drifts and the gyro errors coefficients are considered as the state variables. The attitude information of Star Sensor is used as the high-accurate information to construct the observation with the attitude information of INS. Taken the nonlinearity of the actual system into account, the nonlinear filter Cubature Kalman Filter (CKF) is used to estimate the gyro errors commendably. The experiment results showed that the positioning error reduced a lot by utilizing this novel method.