Theoretical derivation and numerical analysis for droplet's boundary diffraction

CEN Jia-sheng; WANG Qing-mei; LUO Hui; WU Qiang

doi:10.3969/j.issn.1001-3806.2011.06.030

To study the microphysical characteristics of clouds and precipitation, theoretical boundary diffraction field was derived according to Young's boundary diffraction theory and diffraction field distributions were established under exposure of point light source on the optical axis and parallel monochromatic light with the Fraunhofer approximation, the boundary diffraction field of droplet under exposure of monochromatic parallel light was simulated with MATHEMATICA and MATLAB. Furthermore, the effect of boundary diffraction on droplet detection was analyzed and accordingly a threshold change solution was put forward. It is concluded that diffraction by an aperture is addition of geometric projection and boundary diffraction, boundary diffraction is caused by non-uniformity of particles'edge, varying with size and shape. It is meaningful for the detection of droplets.

Theoretical derivation and numerical analysis for droplet's boundary diffraction

Corresponding author: WANG Qing-mei, wqm66666@sina.com;

1. College of Opto-Electronics Science and Technology, National University of Defense Technology, Changsha 410073, China;

2. Beijing Institute of Aeronautical Meteorology, Beijing 100085, China;

3. 95844 Unit, Chinese People's Liberation Army, Jiuquan 735018, China

Received Date: 2011-03-22

Accepted Date: 2011-04-07

Available Online: 2011-11-25

Abstract: To study the microphysical characteristics of clouds and precipitation, theoretical boundary diffraction field was derived according to Young's boundary diffraction theory and diffraction field distributions were established under exposure of point light source on the optical axis and parallel monochromatic light with the Fraunhofer approximation, the boundary diffraction field of droplet under exposure of monochromatic parallel light was simulated with MATHEMATICA and MATLAB. Furthermore, the effect of boundary diffraction on droplet detection was analyzed and accordingly a threshold change solution was put forward. It is concluded that diffraction by an aperture is addition of geometric projection and boundary diffraction, boundary diffraction is caused by non-uniformity of particles'edge, varying with size and shape. It is meaningful for the detection of droplets.

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Reference (10)

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Theoretical derivation and numerical analysis for droplet's boundary diffraction

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References

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