Technique for simulating anisoplanatic image formation over long horizontal paths

Abstract

The presence of turbulence over horizontal imaging paths severely reduces the resolution available to imaging systems and introduces anisoplanatic distortions in the image frame. A variety of image processing techniques are being developed which can mitigate these effects, and sequences of high-fidelity images created via simulation are useful in their development. In this paper, we describe a simplification of the split-step wave propagation method that employs a series of uniformly spaced phase screens to accurately simulate turbulence effects on imaging over horizontal paths. Employing this method, a series of 1000 image frames were generated for each of three turbulence conditions. The mean squared error in intensity per pixel is also evaluated for each frame in comparison to a diffraction-limited reference. Examination of the per-frame intensity error statistics indicate these errors are log-normally distributed about a mean value that increases approximately linearly with turbulence strength.