Defence Science Journal

  • Year: 2009
  • Volume: 59
  • Issue: 5

Error Analysis of Aerosol Extinction Cross Section Measurement due to Forward Scattering and Diffraction

  • Author:
  • Yuan Zhongcai#, Shi Jiaming#, Wang Jiachun#, Xu Bo#
  • Total Page Count: 4
  • DOI:
  • Page Number: 545 to 548

* State Key Laboratory of Pulse Power Laser Technology, Hefei Electronic Engineering Institute, Hefei 230037, China.

#Key Lab of Infrared and Low Temperature Plasma of Anhui Province, Hefei Electronic Engineering Institute, Hefei 230037, China.

Abstract

Aerosol is a useful mean in electro-optical defence. The optical transmissivity is usually used to evaluate the performance of the aerosol. However in transmissivity measurement, forward-scattered or diffracted light might reach the detector and would be incorrectly recorded as unscattered and transmitted one, which results in the final optical density rise and experimental extinction cross-section becoming erroneously low. Based on forward scattering and diffraction analysis, the beam efficiency and effective extinction efficiency are introduced to examine the error. The results indicate that large particles and detector increase the error. To minimise the error, the distance between the aerosol and the detector must be large enough, and the detector of small area and small view angle is favourable.

Keywords

Effective extinction efficiency, forward scattering, diffraction, optical transmissivity, aerosol, diffraction analysis, error analysis