Atmospheric turbulence is a well-known phenomenon that often degrades image quality due to intensity fluctuations, distortion, and blur in electro-optic and thermal imaging systems. To properly assess the performance of an imaging system over the typical turbulence trade space, a time consuming and costly field study is often required. A fast and realistic turbulence simulation will allow the performance assessment of an imaging system under various turbulence conditions to be done as well as provide input data for the evaluation of turbulence mitigation algorithms in a cost efficient manner. The simulation is based on an empirical model with parameters derived from the first and second-order statistics of imaging distortions measured from field collected data. The dataset consists of image sequences recorded with a variable frame rate visible camera from strong to weak turbulence conditions. The simulation uses pristine, single images containing no turbulence effects as an input and produces image sequences degraded by the specified turbulence. Target range, optics diameter, wavelength, detector integration time, and the wind velocity component perpendicular to the propagation path all contribute to the severity of the atmospheric turbulence distortions and are included in the simulation. The addition of the detector integration time expands the functionality of the simulation tool to include imagers with lower frames rates. Examples are presented demonstrating the utility of the turbulence simulation.

Date Published: 12 May 2015
PDF: 13 pages
Proc. SPIE 9452, Infrared Imaging Systems: Design, Analysis, Modeling, and Testing XXVI, 94520B (12 May 2015); doi: 10.1117/12.2176985

Published in SPIE Proceedings Vol. 9452:
Infrared Imaging Systems: Design, Analysis, Modeling, and Testing XXVI
Gerald C. Holst; Keith A. Krapels, Editor(s)