iCATSI: multi-pixel imaging differential spectroradiometer for standoff detection and quantification of chemical threats

Abstract

Homeland security and first responders are often faced with safety situations involving the identification of unknown volatile chemicals. Examples include industrial fires, chemical warfare, industrial leak, etc. The Improved Compact ATmospheric Sounding Interferometer (iCATSI) sensor has been developed to investigate the standoff detection and identification of toxic industrial chemicals (TICs), chemical warfare agents (CWA) and other chemicals. iCATSI is a combination of the CATSI instrument, a standoff differential FTIR optimised for the characterization of chemicals and the MR-i, the hyperspectral imaging spectroradiometer of ABB Bomem based on the proven MR spectroradiometers. The instrument is equipped with a dual-input telescope to perform optical background subtraction. The resulting signal is the difference between the spectral radiance entering each input port. With that method, the signal from the background is automatically removed from the signal of the target of interest. The iCATSI sensor is able to detect, spectrally resolve and identify 5 meters plumes up to 5 km range. The instrument is capable of sensing in the VLWIR (cut-off near 14 mu m) to support research related to standoff chemical detection. In one of its configurations, iCATSI produces three 24 x 16 spectral images per second from 5.5 to 14 mu m at a spectral resolution of 16 cm(-1). In another configuration, iCATSI produces from two to four spectral images per second of 256 x 256 pixels from 8 to 13 mu m with the same spectral resolution. Overview of the capabilities of the instrument and results from tests and field trials will be presented.