An Optical Inversion Technique To Remotely Sense Atmospheric Turbulence Spectra, C 2 n Profiles And Cross-Wind Velocity

Abstract

A remote sensing technique is theoretically developed whereby the temporal frequency spectrum of the scintillations of a stellar source or a point source within the atmosphere, observed through a variable radius aperture, is related to the space-time spectrum of atmospheric scintillation. The key to this spectral remote sensing method is the spatial filtering performed by a finite aperture. The entire method is developed without resorting to a priori information such as results from stochastic wave propagation theory. Having obtained the space-time spectrum of scintillations, an application of known results of atmospheric wave propagation theory and simple geometric considerations are shown to yield information such as the spectrum of atmospheric turbulence, the path averaged cross-wind velocity, and the path profile of the atmospheric refractive index structure parameter. The success of this proposed remote sensing method relies on the solution to a Fredholm integral equation of the first kind. A solution is obtained and a proof is given demonstrating the well-posedness (in the sense of Hadamard) of this inverse problem.