Measurement and analysis of infrared atmospheric aerosol blur

Infrared image quality can be degraded by atmospheric aerosol scattering. Aerosol interactions are dependent upon the atmospheric conditions and wavelength. Measurements of an edge target at range in the LWIR under hot humid weather provided a blur on the image plane, which is characterized by an MTF. In this experiment, the edge spread function, measured at range, was differentiated to obtain the line spread function and transformed into a MTF. By dividing the total measured MTF by the imager and turbulence MTFs, the aerosol MTF was obtained. Numerical analysis performed using MODTRAN and existing known scattering theory was compared with the experimental results. The measured and numerical results demonstrated a significant aerosol MTF suggesting that the aerosol MTF should be included in sensor performance analysis.

[1]  A Ishimaru,et al.  Modulation transfer function of layered inhomogeneous random media using the small-angle approximation. , 1986, Applied optics.

[2]  Piero Bruscaglioni,et al.  A Numerical Procedure for Calculating the Effect of a Turbid Medium on the MTF of an Optical System , 1991 .

[3]  Limits of the small-angle approximation to the radiative transport equation. , 2001, Journal of the Optical Society of America. A, Optics, image science, and vision.

[4]  Piero Bruscaglioni,et al.  Atmospheric scattering effect on spatial resolution of imaging systems , 1997 .

[5]  Akira Ishimaru,et al.  Wave propagation and scattering in random media , 1997 .

[6]  Norman S. Kopeika,et al.  Atmospheric turbulence modulation transfer function for infrared target acquisition modeling , 2001 .

[7]  Richard H Vollmerhausen,et al.  Atmospheric modulation transfer function in the infrared. , 2004, Applied optics.

[8]  Norman S. Kopeika,et al.  A System Engineering Approach to Imaging , 1998 .

[9]  Y. Kaufman.  Atmospheric effect on spatial resolution of surface imagery. , 1984, Applied Optics.

[10]  Norman S. Kopeika,et al.  Imaging through the atmosphere: practical instrumentation-based theory and verification of aerosol modulation transfer function , 1993 .

[11]  Yitzhak Yitzhaky,et al.  Aerosol MTF revisited , 2014, Defense + Security Symposium.

[12]  D Sadot,et al.  Effects of absorption on image quality through a particulate medium. , 1994, Applied optics.

[13]  Gerald C. Holst,et al.  Electro-Optical Imaging System Performance , 1995 .

[14]  Michael C Roggemann,et al.  Detailed effects of scattering and absorption by haze and aerosols in the atmosphere on the average point spread function of an imaging system. , 2014, Journal of the Optical Society of America. A, Optics, image science, and vision.

[15]  C. Bohren,et al.  An introduction to atmospheric radiation , 1981 .

[16]  Michael T. Eismann,et al.  Aerosol modulation transfer function model for passive long-range imaging over a nonuniform atmospheric path , 2013 .

[17]  I. Dror,et al.  Experimental comparison of turbulence modulation transfer function and aerosol modulation transfer function through the open atmosphere , 1995 .

[18]  J. Mooney,et al.  Measurement of the modulation transfer function of infrared cameras , 1995 .

[19]  H. V. Hulst.  Light Scattering by Small Particles , 1957 .