Standoff Detection of Chemical and Biological Substances using Laser Induced Fluorescence Technique

Abstract

Laser based standoff detection methods are convenient to investigate unknown/hazardous chemical or biological aerosol clouds at a safe distance in order to trigger further counteractions if necessary. Classification and localization of such clouds can be provided by laser induced fluorescence (LIF). At Lampoldshausen the German Aerospace Center (DLR) operates a 135 m long laser test range, where LIF measurements on aerosols, liquids, and solids can be performed. Fluorescence light of test material, which is illuminated by a laser source with UV wavelengths, is collected by a telescope and analyzed spectrally as well as time resolved by means of a gated spectrograph. LIF measurements on liquids and aerosols at a distance of 22 m show adequate fluorescence signal strength with a good signal to noise ratio. The data analysis has the ability to distinguish between biological and chemical material with a good prediction confidence level.