Thermal luminescence sensor for ground-path contamination detection.

Abstract

A standoff method of detecting liquids on terrestrial and synthetic landscapes is presented. The interstitial liquid layers are identified through their unique molecular vibration modes in the 7.14-14.29-microm middle infrared (fingerprint) region of liberated thermal luminescence. Several seconds of 2.45-GHz beam exposure at 1.5 W cm(-1) is sufficient for detecting polydimethyl siloxane lightly wetting the soil through its fundamental Si-CH3 and Si-O-Si stretching modes in the fingerprint region. A detection window of thermal opportunity opens as the surface attains maximum thermal gradient following irradiation by the microwave beam. The contaminant is revealed inside this window by means of a simple difference-spectrum measurement. Our goal is to reduce the time needed for optimum detection of the contaminant's thermal spectrum to a subsecond exposure from a limited intensity beam.

Cite this paper

@article{Carrieri1999ThermalLS, title={Thermal luminescence sensor for ground-path contamination detection.}, author={Arthur H. Carrieri and I F Barditch and David J. Owens and Erik S Roese and Peng Lim and M V Talbard}, journal={Applied optics}, year={1999}, volume={38 27}, pages={5880-6} }