Abstract: The nutation angle of projectile is one of the important factors which influence the firing dispersion, and has been a hot issue in the gun research field. In order to get the measurement result of nutation angle near the exit position of projectile, the trajectory tracking method with high speed photography is used to research the nutation angle of projectile. A trajectory tracking system is presented with the high speed photography and the trajectory tracking mount. The image of the projectile flight trajectory is recorded, and the nutation angle of the up-and-down nutation of projectile is got by means of the image analysis software. An example of a gun projectile is demonstrated with the trajectory tracking system, and the rule of up-and-down nutation of projectile near exit position is obtained. The data dispersity of nutation angles for different projectiles is large, and the maximum nutation angle of the first projectile is -5.2°. It is shown that the trajectory tracking method is a perfect method for getting the measurement result of the nutation angle.

Key words: ordnance science and technology, gun, projectile, nutation angle, measurement, high speed photography, trajectory tracking