An Experimental Measurement of the Susceptibility of Spatial Filter Profiling Techniques to Saturation

The current interest in the use of spatial filtering techniques to profile wind and refractive-index turbulence raises the question of how saturation of scintillation may affect these systems. Some experimental observations of saturation effects have now been made with a wind profiling system that is under development at the Wave Propagation Laboratory. The wind profiling technique, which is a modification of a method originally proposed by Lee,1 employes zero-mean spatial filters at both the transmitter and receiver to restrict the observation of refractive-index irregularities moving across a light path to those of a particular spatial wavelength and at a particular location along the path. The wind profiling system employs a number of sets of spatial filters of different spatial wavelengths to measure winds simultaneously at various path positions.