In order to iteratively improve an atmospheric optical communications system, a benchtop method of testing its behavior must be developed. We have developed a simple table top source of turbulence and instrumented it to accurately measure the current turbulent state. With this tool, the development of optical communication subsystems such as the Boeing Optical Communications Receiver Array (OCRA) can be optimized in the laboratory before they are tested in the atmosphere.The Tabletop Turbulence Generator is uses a small, low speed wind tunnel with a grid of heated rods at the head of the test section. This creates a turbulent flow with a characteristic scale of～ 6-30 mm and maximum angular disturbances of ～ .1 milliradians. This is a reasonable scale for 1 and 2 inch optical systems. A crucial element in this Turbulence Generator is instrumentation to allow us to measure the turbulent state. We have implemented a Shack-Hartmann sensor operating at 30 Hz and a Malley probe providing time resolved data along two lines of sight with a time resolution of. 1 milliseconds. We have used this system to characterize the performance of communications receivers and will present this as a pilot study of the Turbulence Generator's performance.
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