Abstract

In the theory of atmospheric turbulence, the strength of the spatial variations of the index of refraction n is proportional to a parameter known as the atmospheric-structure constant. The atmospheric-structure constant is denoted $C_n^2(z)$ and is a function of position along the optical path z. The characteristics of the temporal variations of the index of refraction are related to both $C_n^2(z)$ and to the transverse wind velocity V(z). Current optical techniques for remotely sensing $C_n^2(z)$ and V(z) rely primarily on the spatial or temporal cross-correlation properties of the intensity of the optical field. In the remote-sensing technique proposed here, we exploit the correlation properties of the wave-front slope measured from two point sources to obtain profiles of $C_n^2(z)$ and V(z). The two sources are arranged to give crossed optical paths. The geometry of the crossed paths and the characteristics of the wave-front slope sensor determine the achievable resolution. The signal-to-noise ratio calculations indicate the need for multiple measurements to obtain useful estimates of the desired quantities.

© 1994 Optical Society of America

Sensing refractive-turbulence profiles (Cn²) using wave front phase measurements from multiple reference sources

Byron M. Welsh
Appl. Opt. 31(34) 7283-7291 (1992)

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Remote sensing of wind velocity and strength of refractive turbulence using a two-spatial-filter receiver

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Characterization of atmospheric turbulence phase statistics using wave-front slope measurements

Eric E. Silbaugh, Byron M. Welsh, and Michael C. Roggemann
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Signal-to-noise ratio for astronomical imaging by deconvolution from wave-front sensing

Michael C. Roggemann and Byron M. Welsh
Appl. Opt. 33(23) 5400-5414 (1994)