Open Path Optical Sensing of Particulate Matter used asMilitary Obscurants

摘要

Fugitive particulate matter (PM) monitoring technology development is a high priority researchand development topic for technology users under the U.S. Army Environmental QualityTechnology Program. Until the present time, there has been no scientifically reliable Federal orState standard protocol to monitor fugitive PM. In real world situations, the best method is afilter-based measurement in the plume at a fixed location. However, the filter-based measurementshave many limitations and alternative PM monitoring technology development is critical.The U.S. Army Engineer Research and Development Center (ERDC) - Construction EngineeringResearch Laboratory (CERL) and ARCADIS have been investigating an integrated optical remotesensing (ORS) approach for characterizing PM by measuring multi-spectral light extinction. Thispresentation focuses on the most recent experiments performed in September 2004 using dust andfogoil samples. The open path ORS instruments used in this study include a monostatic OpenPath-Fourier Transform Infrared (OP-FTIR) Spectrometer and a prototype visible LightDetection and Ranging instrument (LIDAR) collecting light extinction data through the controlledcloud of PM. An aerodynamic particle-sizer (APS) was used to measure mass distribution directlyand in real time during the PM plume’s release. An inverse Mie theory algorithm was used toretrieve mass distribution from the combined ORS instrument measurements. The retrieved massdistribution agrees well with the APS measurements.