Tracing of Light Rays Along a Projectile Wake
Abstract
The propagation of optical radiation longitudinally through the turbulent wake of a supersonic projectile is studied by means of geometrical optics. The differential equations for propagation of light rays in a non- homogeneous medium are integrated numerically for light traveling upstream from a pulsed point source located behind a moving projectile, and the shadow formed on a film located ahead of the projectile is calculated. The index of refraction is obtained from a semi-empirical model for the gas density in the wake. The calculated magnification of the projectile shadow diameter agrees with measured values to within 5%; such consistency between the calculations and experimental data is taken as justification of the model. This result suggests that geometrical optics is adequate for tracing rays along a wake and, therefore, for performing design calculations in the development of an optical miss distance sensor and design systems for beam rider projectiles and missiles.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1978
- Accession Number
- ADA064099
Entities
People
- J. M. Bartos
- N. Gerber
- R. Sedney
Organizations
- Ballistic Research Laboratory