A Methodology for Reflected Laser Beam Hazard Analyses

Previous reflected laser beam hazard evaluations have been based primarily on simplifying and overly conservative assumptions. In the case of high-energy laser (HEL) field tests, such assumptions typically produce Reflected Nominal Ocular Hazard Distance (RNOHD) results that cannot be contained within the boundaries of existing test ranges. This severely limits the ability to test HEL systems under operational conditions. A methodology was developed to address the need of the laser safety community for a more rigorous and accurate procedure to determine RNOHDs to support HEL field tests. The methodology consists of several physically based models and is applicable to scenarios in which a single laser illuminates a target and both the laser and target can be moving along independent trajectories. The salient features of the methodology are consideration of reflections only in the specular direction, the use of reflecting properties of actual materials, and the calculation of exposure times for specific engagement scenarios. The equations and procedures of the methodology are demonstrated using an example engagement scenario.
Published in Journal of Directed Energy, v3 p320-342, Summer 2010.