Measurement of the spatial coherence of light influenced by turbulence

To evaluate the Earth's surface with a sensor on a satellite, it is important for one to use a correction factor such as atmospheric turbulence. The spatial coherence of light influenced by turbulence was measured in the laboratory by use of a simulator equipped with a multiple reflection system. The turbulence was generated by changing the ambient temperatures from 32 to 48 degrees C. It was found that the spatial coherence of light that passed through the turbulent region decreased when the temperature increased. Double-slit interference fringes were analyzed by a photographic method. The visibility of the interference fringes is the degree of coherence.