<title>Remote sensing of atmospheric turbulence and transverse atmospheric winds using optical reference sources</title>

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, denoted Cn2, which is a function of position along the optical path z. The strength of the temporal variations of the index of refraction is directly related to the transverse velocity YLDV of the turbulence along z. Current optical techniques for remotely sensing Cn2 and YLDV rely primarily upon the spatial or temporal cross-correlation properties of the intensity of the optical field. In the technique proposed here, we exploit the correlation properties of the wave front slope measured from two different point sources in order to obtain vertical profiles of Cn2(z) and YLDV(z). Resolution on the order of 100 meters is possible with reference sources separated by 0.2 degrees. Additionally, signal-to-noise ratio (SNR) calculations for a single measurement of Cn2 and YLDV are presented for a Hufnagel-Valley Cn2 profile and a Bufton wind profile. The SNR results indicate the need for multiple measurements to obtain useful estimates of the desired quantities.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.