Accession Number : AD0426175

Title :   A PHOTO-OPTICAL SYSTEM FOR THE MEASUREMENT OF PROJECTILE VELOCITY,

Corporate Author : ARMY NATICK LABS MASS CLOTHING AND ORGANIC MATERIALS LAB

Personal Author(s) : Tanenholtz,Stanley D.

Report Date : OCT 1963

Pagination or Media Count : 52

Abstract : A photo-optical system has been developed for determining the velocity of a projectile after target penetration. This system provides a wide field of view and overcomes the difficulties introduced by light from the projectile-target impact and by the pretriggering of velocitymeasuring transducers by particles broken from the target. The system employs a parallel-light shadowgraphic method that consists of a doublespark source at the focal point of a converging Fresnel lens, and another similar lens to focus the light into a camera. The system is activated by the projectile which, after penetrating the target, triggers a transducer whose pulse is fed to a delay unit. The delay unit in turn triggers the spark unit when the projectile is within the parallel-light field. The result is a shadowgraph of the projectile and the accompanying punchout material in two positions. The distance between the two images on the photograph (corrected by a suitable magnification factor) divided by the spark time interval gives the average velocity of the projectile. This system enables the measurement of residual velocity with an error of only 1 to 2 percent and, at the same time, permits the observation of size, shape, distribution of other particles, and distortion of the projectile. (Author)

Descriptors :   (*HIGH SPEED PHOTOGRAPHY, TERMINAL BALLISTICS), (*TERMINAL BALLISTICS, HIGH SPEED PHOTOGRAPHY), VELOCITY, PROJECTILES, PENETRATION, BALLISTICS, PHOTOGRAPHIC ANALYSIS, IMPACT SHOCK, PROJECTILE TRAJECTORIES, BALLISTIC CAMERAS, SHOCK WAVES, MATHEMATICAL ANALYSIS, TEST EQUIPMENT, TEST METHODS, OPTICAL EQUIPMENT

Distribution Statement : APPROVED FOR PUBLIC RELEASE