Mine field detection and identification using THz spectroscopic imaging

The spatial, temporal, and spectroscopic characteristics associated with pulsed THz (100 GHz -70 THz) radiation provide this emerging technology with the potential for reliable identification of buried objects such as non-metallic landmines. With a suitable integration of these attributes, one can envision a THz detection platform that provides: (1) accurate identification of buried objects, and (2) a source-to-sample working distance that is sufficient for remote sensing applications. In our preliminary laboratory studies, we have demonstrated the detection capabilities of THz radiation by imaging a small rubber object embedded in a moist, sand-like soil. Despite the significant attenuation of the THz radiation via water absorption and particle scattering, the initial transmission results showed that pulsed THz imaging could identify the non-metallic object when buried in a few inches of soil. The sub-millimeter resolution observed in our THz images illustrates the potential to discriminate landmines from other buried objects. Finally, THz calculations and measurements determined that our current THz source and detector has sufficient SNR to detect a buried object to a depth of 6 inches in moist sand.