Predicting imaging performance in turbulence

摘要

Estimates of the performance of an imager working in a turbulent atmosphere can often be obtained if an estimate of the index of refraction structure constant (C_n~2) is available. In this paper, results from predictive parametric models for C_n~2 are compared with long-term measurements of C_n~2. A brief overview of imaging in turbulence is given. The impact of turbulence on imager performance and models to account for it are reviewed. This is followed by a presentation of the methods used to collect C_n~2 data. Some published parametric models for predicting C_n~2 based on meteorological data are reviewed. These models are then compared with C_n~2 measurements taken over several years. Performance of the models as a function of time of day and season of year are shown. General conclusions regarding the utility of using these models to predict system performance are presented.