| Trajectory correction technology is the important development direction of intelligent ammunitions, as the key technology to improve the attack precision of conventional ammunitions. Real-time and accurate attitude calculation is a key technology for two dimensional correction of high speed spinning trajectory. An attitude measurement system is designed to realize the roll angle measurement for high spinning projectile under the environment of its huge shock & high speed characteristics. A series of work has been done including roll angle calculation, EMC design, hardware & software design, error calibration and flight test, et al.The model of coordinate transformation and roll angle calculation has been researched according to geomagnetic field’s and magnetoresistive sensor’s characteristics. A simplified real-time attitude calculation model is proposed from the request of engineering application. In order to reduce or eliminate the influence to the attitude measurement system produced by projectile body remanence and the servo system, we carried out electromagnetic shielding & filter design on it and verified its reliability through the experiment. We used least square fitting to obtain linear phase compensation model by dividing phase-frequency curve which was provided by theoretical model and ap-FFT algorithm. We used three-axis table to calibrate the magnetoresistor’s error and the mean deviation was 10°.A roll angle measurement system based on phototransistor and solar azimuth is designed to evaluate the measurement accuracy of projectile roll angle using geomagnetic field. We verified the system’s anti-interference ability with the data from the flight test. The maximum difference of roll speed and roll angle are 0.6Hz and 6° respectively between geomagnetic-field based method and solar azimuth based method at the same time base. And our designed system can satisfied the requirements for high rotational projectiles.
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