Abstract

The twinkling of stars produced by atmospheric turbulence is familiar to even the casual observer. The fact that the sun also twinkles, however, is not so widely known. This paper describes a series of experiments aimed at determining the statistical characteristics of solar scintillation. Measurements were made of the fractional scintillation, the spatial correlation of the irradiance fluctuations, the amplitude distribution of the irradiance, and the frequency spectrum of the fluctuations. The fractional scintillation of the sun was found to be of the order of 5×10⁻⁴. The spatial-correlation function of the solar irradiance fluctuations was found to be a very rapidly decreasing function of the separation between detectors. The correlation decreased to 50% for a spatial separation of only 7 mm. The probability distribution of the irradiance is very accurately described by a gaussian distribution, and the major portion of the frequency spectrum of the fluctuations lies below about 100 Hz.

© 1971 Optical Society of America

Holographic Method of Measuring Scintillation Effects

P. H. Deitz and J. M. Evans
Appl. Opt. 10(5) 1080-1082 (1971)

Airborne laser-beam scintillation measurements at high altitudes*

Glen J. Morris
J. Opt. Soc. Am. 63(3) 263-270 (1973)

Measurements of Laser-Beam Scintillation in the Atmosphere

D. L. Fried, G. E. Mevers, and M. P. Keister
J. Opt. Soc. Am. 57(6) 787-797 (1967)

Simultaneous measurements of angular scattering and intensity scintillation in the atmosphere

W. A. Coles and R. G. Frehlich
J. Opt. Soc. Am. 72(8) 1042-1048 (1982)

Spectral and Angular Covariance of Scintillation for Propagation in a Randomly Inhomogeneous Medium

D. L. Fried
Appl. Opt. 10(4) 721-731 (1971)