Probabilistic laser hazard modelling for a fifth-generation low-observable laser designator system

Abstract

The advent of so-called “fifth-generation” low-observable strike aircraft with a laser designation capability raises a potentially unique laser hazard. In order to be “stealthy”, the laser designator is likely to be embedded within the aircraft rather than carried externally as a podded system. The difference between an integrated and a pod-based configuration is that the laser exit window in a stealth design is likely to be fixed to the aircraft fuselage, as opposed to being able to move with the laser beam, and it is also likely to be faceted. Unless carefully engineered, a faceted exit window may generate unintended laser beam reflections resulting in stray laser energy (SLE) emissions, as the laser head rotates within the window assembly.High intensity SLE can engender impractically large laser hazard zones using traditional deterministic analysis techniques. The purpose of this paper is to outline the probabilistic modelling of uncontrolled SLE from a hypothetical integrated laser designator system. The discussion will also show the importance of including the aircraft behaviour in the analysis, due to the effect of the aircraft position relative to the target on the SLE scatter patterns.The advent of so-called “fifth-generation” low-observable strike aircraft with a laser designation capability raises a potentially unique laser hazard. In order to be “stealthy”, the laser designator is likely to be embedded within the aircraft rather than carried externally as a podded system. The difference between an integrated and a pod-based configuration is that the laser exit window in a stealth design is likely to be fixed to the aircraft fuselage, as opposed to being able to move with the laser beam, and it is also likely to be faceted. Unless carefully engineered, a faceted exit window may generate unintended laser beam reflections resulting in stray laser energy (SLE) emissions, as the laser head rotates within the window assembly.High intensity SLE can engender impractically large laser hazard zones using traditional deterministic analysis techniques. The purpose of this paper is to outline the probabilistic modelling of uncontrolled SLE from a hypothetical integrated laser designator system. ...