Relation between irradiance and log-amplitude variance for optical scintillation described by the K distribution

Abstract

We derive the relationship between log-amplitude (or log-irradiance) variance and irradiance variance for optical scintillation described by a K probability distribution. The results indicate that all observations of maximum variance values, whether log-irradiance or irradiance data are used, are consistent. The K distribution appears to be a reasonable assumption for scintillation in the region of maximum variance. The K distribution is also consistent with data and theory in the very strong refractive turbulence region where exponential irradiance statistics are observed.