The Optical Reference Error Analysis and Control Method in Ground Validation System of Stellar-Inertial Integration

The authenticity of the Stellar-Inertial integration ground validation system will eventually determine the navigation performance in flight. The optical reference error characteristics remain a crucial but unsolved issue due to the arc-second level accuracy in the ground validation system. The characteristic of the star simulator celestial angle error and the north reference error are discussed and analyzed in detail. A new error control method of the star simulators intersection angle is proposed with the help of the high precision three-axis turntable. The north reference error can be isolated as a certain azimuth bias error in ground validation. The synthesis of all the error sources is performed to give the criterion value of the evaluation accuracy for the ground validation system. Experimental tests confirm that the error analysis and control method are effective. The evaluation accuracy is improved from 10.99 to 4.88 arc-seconds under the condition of remaining the unchanged ground validation system. Meanwhile, such an in ground test system is close to the flight conditions and it can satisfy the stringent requirement for high-accuracy star sensors.