Full-field mapping and analysis of veiling glare sources for helmet-mounted display systems

Abstract

The performance of an optical system can be degraded by the intrusion of stray light form sources both inside and outside of the system field of view. Stray light, or 'veiling glare,' can be particularly distracting in visual systems such as Helmet Mounted Display (HMD) systems. This paper describes techniques used by the authors to map stray light sources positions in the far field for HMD systems and to quantitatively define their impact. The mapping can be performed over 4(pi) steradians both inside and outside the system field of view. Monte-Carlo ray tracing algorithms are utilized for determining that separates the veiling glare component from the desired optical signal components. Once the major veiling glare source positions are identified, methods to reduce veiling glare can be determined. A technique for reducing noise in the calculation due to the statistical nature of the Monte Carlo ray trace is also discussed.