Atmospheric turbulence modulation transfer function for infrared target acquisition modeling

2001 ◽  
Vol 40 (9) ◽  
pp. 1906 ◽  
Author(s):  
Keith Krapels
Keyword(s):  
Transfer Function ◽  
Atmospheric Turbulence ◽  
Modulation Transfer Function ◽  
Target Acquisition ◽  
Modulation Transfer ◽  
Turbulence Modulation

scholarly journals Modulation Transfer Function of a Gaussian Beam Based on the Generalized Modified Atmospheric Spectrum

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Chao Gao ◽  
Xiaofeng Li
Keyword(s):  
Transfer Function ◽  
Gaussian Beam ◽  
Atmospheric Turbulence ◽  
Modulation Transfer Function ◽  
Spectral Power ◽  
Optical Parameters ◽  
Modulation Transfer ◽  
Negative Effects ◽  
Kolmogorov Turbulence ◽  
Inner Scale

This paper investigates the modulation transfer function of a Gaussian beam propagating through a horizontal path in weak-fluctuation non-Kolmogorov turbulence. Mathematical expressions are obtained based on the generalized modified atmospheric spectrum, which includes the spectral power law value of non-Kolmogorov turbulence, the finite inner and outer scales of turbulence, and other optical parameters of the Gaussian beam. The numerical results indicate that the atmospheric turbulence would produce less negative effects on the wireless optical communication system with an increase in the inner scale of turbulence. Additionally, the increased outer scale of turbulence makes a Gaussian beam influenced more seriously by the atmospheric turbulence.

Observer Performance Using a Video Display

1977 ◽  
Vol 21 (5) ◽  
pp. 406-410
Author(s):  
William S. Beamon
Keyword(s):  
Image Quality ◽  
Transfer Function ◽  
White Noise ◽  
Modulation Transfer Function ◽  
Observer Performance ◽  
Target Acquisition ◽  
Modulation Transfer ◽  
Area Metric ◽  
Acquisition Task

An experiment was conducted to assess observer performance in a simulated air-to-ground target acquisition task. Terrain films depicting targets imbedded in rural scenery were presented by a closed-circuit video system which employed two methods of varying the image quality of the display. The effects produced by these methods, spot wobble and random or ‘white’ noise added to the video signal, were independently manipulated, photometrically measured, and included in the Modulation Transfer Function Area metric of image quality. Correlation with observer target acquisition data suggest that the predictive validity of the Modulation Transfer Function Area (MTFA) concept may be improved by the addition of a third function incorporating some portion of the power spectrum of the imaged scene. The facilitory effects produced by spot wobble and the deleterious effects of white noise on observer performance were also demonstrated.

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