A comprehensive model for calculating the degrading effects of atmospheric turbulence on the performance of long-range, airborne imaging systems is described. The model output is the Modulation Transfer Function (MTF) of the turbulent air in the conical ray bundle from the target to the sensor. Published data from the field of astronomy and other theoretical developments are incorported into the formulation. Two difficulties with previous formulations are avoided: the requirement to set a parameter to one of two values for near or far field geometry; and the requirement to choose between two different formulations for short and long exposures. These are handled in an automatic and continuous manner in this new model. Also, it was found that the index of refraction turbulence structure coefficient (Cn2) altitude profile has about the same value and appearance over most of the world; therefore, the Cn2 altitude profile is integrated and a plot of the results (parameter Ch) is included.
T. J. Schulze,
"Calculating The Modulation Transfer Function Of Atmospheric Turbulence", Proc. SPIE 1156, Airborne Reconnaissance XIII, (1 February 1990); doi: 10.1117/12.962479; https://doi.org/10.1117/12.962479