A Fibre Optic Sensor for High-velocity Measurements of Projectiles Driven by Hot Gases

Abstract

A fibre optic sensor system for the measurement of the velocity of projectiles propelled by hot gases has been developed. It was found that fibre optic techniques have significant advantages over conventional breakwire methods in this electromagnetically noisy environment. A simple passive fibre system produced both accurate and reliable measurements of projectile velocities which, in this study, were in the range 1-3 km s-l. In addition, by using a number of fibres at different positions along the projectile path, the average velocity of the projectile can be determined at several points, and a velocity profile for the projectile motion obtained.