Abstract

In the theory of atmospheric turbulence, the strength of the spatial variations of the index of refraction n is characterized by the power spectral density (psd) ${\Phi }_n(\overrightarrow{K})$ where $\overrightarrow{K}$ is the wavenumber vector. The magnitude of ${\Phi }_n(\overrightarrow{K})$ is proportional to a parameter known as the atmospheric structure constant of the refractive index fluctuations. The atmospheric structure constant is denoted $C_n^2$ and is a function of position along the optical path. In addition to spatial variations, n is also characterized by temporal variations. The strength of these temporal variations is directly related to the transverse velocity of the turbulence along the optical path, v.

© 1992 Optical Society of America