Hyperspectral gas and polarization sensing in the LWIR: Recent results with MoDDIFS

Imaging Fourier-transform infrared (FTIR) spectroscopy is a powerful method for the passive remote detection and identification of vapor emanations and surface contaminations. In the Defense and Security context, imaging FTIR can be used for the remote surveillance of locations suspected of illicit product fabrications. DRDC Valcartier recently initiated the development and field-validation of the novel imaging FTIR sensor MoDDIFS (Multi-option Differential Detection and Imaging Fourier Spectrometer) to address this remote sensing application. The proposed system combines the clutter suppression efficiency of the differential detection approach with the high spatial resolution provided by the hyperspectral imaging approach. The MoDDIFS sensor includes two configuration options, one for remote gas detection, and the other for polarization sensing of surface contamination. This paper reviews recent results obtained with MoDDIFS for the passive standoff detection of gases and liquid contaminants. Hyperspectral measurements done on difluoroethane, diethyl ether (gases) and SF96 (liquid) serve to develop, test and validate GLRT-type detection algorithms. Detection results are presented and discussed in terms of the GLRT detection attributes.