A quantitative method for detecting explosive materials using terahertz spectroscopy

Terahertz transmission spectroscopy offers simultaneous measuring capabilities for the spectral and depth information of the inspected materials. This enables effective determination of the species and amount of them, i.e., qualitative and quantitative detection. We have successfully applied this technique to quantitatively detect concealed explosives by an absorbance spectrum fitting method. Measurement of the amount of RDX sample covered with some barrier materials provides the experimental evidence for the validity of this quantitative method. Two factors relating to the detection accuracy are considered and analyzed, the fitting frequency range and the polynomial approximation of the unknown absorbance of the barrier.