A laser source illuminates a spot on the surface being scanned, whether vehicle, drum, left-behind luggage, etc. Any explosive residue present on the object produces Raman scattering.
Stage II
The scattered light is collected by a telescope and analyzed by a spectrometer and detector. A spectral fingerprint (i.e., the Raman spectrum) is generated in as little as 1-5 seconds.
Stage III
The spectrum is compared with previously recorded Raman signatures of various explosives, and a match alerts the operator to the probable presence of explosive residue.
