For atmospheric turbulence-induced wave-front distortion, the mean-square change in the measured wave-front distortion for two measurements made at times separated by an interval Δt is shown to be equal to (Δt/τG)5/3, where τG is called the Greenwood time constant. It is shown that τG is related to the Greenwood frequency fG by the equation τGfG = 0.134.
© 1990 Optical Society of America
Original Manuscript: August 14, 1989
Manuscript Accepted: February 12, 1990
Published: July 1, 1990
David L. Fried, "Time-delay-induced mean-square error in adaptive optics," J. Opt. Soc. Am. A 7, 1224-1225 (1990)