<title>Electro-optical technology for remote chemical detection and identification</title>

Abstract

The U.S. Army has been involved for over 30 years in the development of remote passive chemical detection sensors. With one exception these sensors have all been based on the Fourier transform spectrometer (FTS). The one exception was an early sensor called LOPAIR (long path infrared) which was a circular variable filter spectrometer. LOPAIR provided low spectral resolution and low sensitivity. Because of the limited sensitivity and resolution the Army quickly started using FTS for all their subsequent passive sensors. The first FTS spectrometer used for chemical detection was built by Block Engineering and was called COIN or correlation interferometer. Since that first FTS, the Army has been involved in the development of more advanced versions and currently has the M-21 in production. Following the M-21 was the development of the lightweight standoff chemical agent detection sensors (LSCAD) which were intended to provide detection on the move. Eight LSCAD sensors were built by the contractor to be used by the Army in either armored vehicles or the Pioneer UAV. Currently Block Engineering is under contract to modify several of the existing LSCAD sensors. The new sensor resulting from this program are referred to as the improved lightweight standoff chemical agent detection sensors (I-LSCAD). The objective of this paper is to describe the I-LSCAD sensor, which represents the state- of-the-art for remote passive chemical detection sensors.