A Practical Ballistic Yaw Sensor

Abstract

It is widely recognized that angled or yawed projectile impacts on armour can affect the perceived performance due to changes in projectile’s interactions with the armour-. Furthermore, spurious results and greater uncertainty in armour performance can result from variations in yaw angles if not accounted for. While many ballistic test standards limit the allowable incident angle, its measurement has long been accomplished with yaw cards despite having poor precision and possible effect on trajectory. This paper describes the development of a non-contact ballistic yaw sensor for small calibre ammunition and fragment simulating projectiles that meets the requirements of ballistic standards while providing much greater precision and ease of use over that of yaw cards. The use of computer vision methods combined with LED lighting has resulted in a system that is quick and simple to use. The setup, operation, data analysis and accuracy are described with examples of its use.