Title :
A comparison of the point spread functions for polarization-difference and intensity-only imaging in scattering media
Author_Institution :
Moore Sch. of Electr. Eng., Pennsylvania Univ., Philadelphia, PA, USA
Abstract :
A possible reason for the observed improvement in the detectability of polarizing targets in polarization-difference (PD) images obtained in scattering media is examined. The point spread function (PSF) of an imaging system indicates how a particular system degrades the image of a point source. Through a convolution with a particular intensity distribution, the effects of scatterers on the image as a whole can also be determined. When imaging in a dense scattering medium, multiple scattering effects causes a widening of the PSF beyond that of the optical imaging system alone (without scatterers). Since multiple scattering also tends to depolarize radiation, it has been hypothesized that polarization-difference imaging (PDI) has a narrower PSF than polarization-sum (PS) imaging because PDI is insensitive to unpolarized radiation. A narrower PSF would allow for less blurring in images and, therefore, better resolution of targets in a scattering medium. Through the use of a Monte-Carlo simulation, the PSFs for an elemental electric dipole source imaged by PS and PD imaging through a slab of scattering medium are explored.
Keywords :
Monte Carlo methods; digital simulation; electromagnetic wave polarisation; electromagnetic wave scattering; image resolution; optical transfer function; simulation; Monte-Carlo simulation; convolution; elemental electric dipole source; intensity distribution; intensity-only imaging; multiple scattering effects; optical imaging system; point spread functions; polarization-difference imaging; polarization-sum imaging; polarizing targets detection; radiation depolarization; scattering media; slab; target resolution; Image resolution; Mie scattering; Optical imaging; Optical scattering; Particle scattering; Polarization; Rayleigh scattering; Reflectivity; Scattering parameters; Slabs;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1997. IEEE., 1997 Digest
Conference_Location :
Montreal, Quebec, Canada
Print_ISBN :
0-7803-4178-3
DOI :
10.1109/APS.1997.625430