Laser Opacity Retroreflector System (LORS)

Army training and other activities that generate plumes of smoke or dust must not exceed EPA opacity limits. However, current methods of measuring opacity rely on subjective "trained observers" which leads to disagreements about the accuracy of observer'sestimates. To provide an accurate and objective means of measuring opacity, POC is proposing to continue Phase II development of their innovative Laser Opacity Retroreflector System (LORS). LORS employs a low-cost, solid-state 35mW laser diode to directa beam through the plume which is then returned by inexpensive retroreflectors positioned up to 2 km away, beyond the plume. Building on the success of recent proof-of-concept demonstrations, POC will further develop a portable LORS prototype that can betripod-mounted, attached to a vehicle, placed on a tower or carried aloft by a balloon or aircraft. The cylindrical retroreflectors eliminate the need for alignment. Also, the eye-safe laser's wide beam eliminates the effects of air turbulence orinterference along the beam's path. A LORS prototype will be completed and field-tested using fog oil and sand-based plumes with protocol based on EPA regulations.