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 atmosphericstructure constant is denoted C(2)(n)(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(2)(n)(z) and to the transverse wind velocity V(z). Current optical techniques for remotely sensing C(2)(n)(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(2)(n)(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 calculationsindicate the need for multiple measurements to obtain useful estimates of the desired quantities.

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 C, 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 V of the turbulence along z. Current optical techniques for remotely sensing C and V 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 C(z) and V(z). Resolution on the order of 100 meters is possible with reference sources separated by 0.2 degrees.

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) Φ n ( K → ) where K → is the wavenumber vector. The magnitude of Φ n ( 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.