A Monte Carlo approach to evaluate Stray Laser Energy from the F-35 Lightning II

The F-35 Lightning II has a powerful combat laser designator operating at a wavelength and energy levels that are damaging to the human eye at a pulse level. Due to the faceted design of the Electro Optical Targeting System housing, unwanted Stray Laser Energy beams are emitted in uncontrolled directions. These beams are powerful enough to damage the human eye. Care must therefore be taken to ensure that observers on the ground are not unintentionally blinded. Using a general procedure where the hazard distance is determined by the length of the strongest Stray Laser Energy beam in any direction impedes the ability of the Royal Norwegian Air Force to train in Norway due to the size of the firing ranges and the limits to the maneuvering envelope. We have developed a Monte Carlo based model to determine the hazard "footprint" on the ground for typical flight patterns. The model incorporates several stochastic variables to catch the variations of an execution. The model also incorporates terrain data to evaluate if a beam will hit the actual terrain around a specified target. By running enough instances of the model, it is possible to generate an estimate for the probability of being hit by a beam for ground observers. Analysis has been performed for the unaided eye, binoculars of size 7x50mm and binoculars of size 20x120mm. By evaluating the risk level in accordance with guidelines provided by the The Norwegian Radiation and Nuclear Safety Authority, we have expanded the possibility for training using the combat laser in Norway.