The Effect of Turbulent Outer Scale on Atmospheric Transverse Coherence Length and Isoplanatic Angles

Abstract : Based on the measured altitude distributional data of the turbulence structure constant ((C sub eta)squared), this article analyzes the effects of turbulent outer scale L sub O on atmospheric transverse coherence length r sub O and isoplanatic angle Theta sub O under the two conditions of large apertures and small apertures. Calculation results clearly show that, under conditions where L sub O is a limited value, r sub o and Theta sub O clearly increase. With regard to large aperture telescopes, in infrared wave bands--for example, wave lengths of 2.2 microns--r sub O and Theta sub O are even larger. Theta sub O can even reach 0.5 mrad.