A PHOTO-OPTICAL SYSTEM FOR THE MEASUREMENT OF PROJECTILE VELOCITY
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 velocity measuring transducers by particles broken from the target. The system employs a parallel-light shadow graphic 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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1963
- Accession Number
- AD0426175
Entities
People
- Stanley D. Tanenholtz
Organizations
- United States Army Soldier Systems Center