Aero Thermo Technology (United States)

An analysis of the effect of inhomeogeneous turbulence on the point-spread function for imaging through a turbulent layer has been performed. The formulation retains the concept of the modulation-transfer function that has been used in the past for homogeneous turbulence layers, but the integration now depends on more than just the separation distance ρ in the plane of the aperture. An example is chosen in which the rms optical path difference increases by a factor of 3.51 from one side of the aperture to the other in the flow direction. It was found that the results were insensitive to the angle between the separation-distance vector ρ and the flow direction. Surprisingly it was found that the detailed resultswere within a few percent of those obtained with constant-turbulence parameters evaluated at the center line of the aperture.