Optomechanical Design of a Field-Deployable Thermal Weapon Sight

摘要

The use of uncooled infrared (IR) imaging technology in Thermal Weapon Sight (TWS) systems produces a unique tool that perfectly fulfills the all-weather, day-and-night vision demands in modern battlefields by significantly increasing the effectiveness and survivability of a dismounted soldier. The main advantage of IR imaging is that no illumination is required; therefore, observation can be accomplished in a passive mode. It is particularly well adapted for target detection even through smoke, dust, fog, haze, and other battlefield obscurants. In collaboration with the Defense Research and Development Canada (DRDC Valcartier), INO engineering team developed, produced, and tested a rugged thermal weapon sight. An infrared channel provides for human detection at 800m and recognition at 200m. Technical system requirements included very low overall weight as well as the need to be field-deployable and user-friendly in harsh conditions. This paper describes the optomechanical design and focuses on the catadioptric-based system integration. The system requirements forced the optomechanical engineers to minimize weight while maintaining a sufficient level of rigidity in order to keep the tight optical tolerances. The optical system's main features are: a precision manual focus, a watertight vibration insulated front lens, a bolometer and two gold coated aluminum mirrors. Finite element analyses using ANSYS were performed to validate the subsystems performance. Some of the finite element computations were validated using different laboratory setups.