Gps-based Air-to-air Missile Inertial Navigation Accuracy Assessment Test Study

Beyond visual range (BVR) is one of the mostly developing trend of air-to-air missile(AAM) in modern times. As the shoot range of AAM is increasing, the accuracy of middle-guidance has more influence on the attack effect, and it lies on the accuracy of inertial navigation system which is on AAM. The error of inertial navigation system will influence attack effect of the guided missiles directly. So to evaluate the accuracy of strap-down inertial navigation system (SINS) on AAM is important to develop SINS, and it is also important to evaluate the attack effect of AAM.This paper introduces the navigation principle of the SINS firstly, the navigation algorithm on geographical coordinates is deduced, and then the simulation program is developed. Based on gyro and accelerometer error characteristic, this paper sets up the error model of SINS, and has simulated and analyzed the error characteristic of SINS on still base.This paper makes an introduction to GPS principle and to the attitude measurement emphatically. It simulates and analyzes the attitude measurement with multi-antenna configured based on GPS. The assistant antenna solves the problem of calculating integer ambiguity, so it can measure attitude in real time.This paper has built up two evaluating projects based on GPS as a reference coordinates, one uses the position and speed information that GPS offers as reference information and the other uses the position and speed and attitude information that GPS offers as reference information and sets up the state equation and observation equation based on error the model of SINS. It also settles the problem of GPS and SINS data synchronization and analyzes the effect of Geometric Dilution of Precision (GDOP). It uses Kalman filter and smooth algorithm to evaluate the error of SINS, and then it simulates and analyzes the evaluating effect of them and gives out the result of simulation. According to the result, when regarding GPS position and speed information as reference information, the effect of evaluating the accuracy of SINS isgood enough already. When the attitude information of GPS is added on and regarded GPS as reference system, the effect of evaluating attitude error of SINS is improved dramatically, so it is a more effective evaluating project.