Environmentally Adaptive Free-Space Optical Communication

Free-space optical communication (FSOC) provides a much higher modulation bandwidth than RF communication. Narrow optical beams provide enhanced security, although they are much more sensitive than RF to platform disturbances and the atmosphere. Turbulence causes beam wander, broadening, and breakup (scintillation) on the transmit laser and dynamic aberrations at the receiver, especially when the path's refractive structure parameter is large. Our approach in Phase I is based on our experience in developing the PROPS and DELTA turbulence sensors, modeling/forecasting turbulence and extinction from environmental measurements and terrain, laser flight testing, and adaptive FSOC research. We propose to integrate an FSOC performance model into our existing SHaRE toolbox, use it and wave-optics simulations to determine an optimally adaptive FSOC keying scheme, and explore its performance in the presence of platform-based and external disturbances for a variety of relevant link geometries and practical measurements.