شناسایی و تشخیص آلاینده های شیمیایی از طریق عکس برداری فراطیفی LWIR منفعل

ABSTRACT Chemical Pollutant Detection And Identification By Passive Lwir Hyperspectral Imaging

Accidental release of gaseous chemical pollutants constitutes a potential risk and important consequences for population health and the environment. In the last decades, development of passive standoff detection demonstrates high potential for long range detection and identification (D&Id) for surveillance of chemical pollutant released in the environment. To perform this surveillance mission, Defence Research and Development Canada (DRDC) has been developing and validating very longwave infrared (LWIR) Fourier transform spectrometer (FTS) systems for passive standoff detection of chemical pollutants. These systems are referred to as the Compact ATmospheric Sounding Interferometer (CATSI) family and are based on a symmetrical double input beam FTS which was designed for real time optical subtraction of the background radiance. The CATSI systems and the associated software were described elsewhere [1-8]. In the last ten years, new development of sensitive Mercury-Cadmium-Telluride (MCT) multi-element or focal plane array (FPA) detectors pave the way of research in the direction of imaging D&Id of chemical pollutants. These technological advances provide detection capability of smaller plumes with a better FOV coverage. DRDC Valcartier is currently developing optical subtraction imaging FTS like iCATSI (improved Compact ATmospheric sounding Interferometer) for the detection and identification of chemical pollutants. The purpose of this paper is to summarize the main results obtained in the last year for the application of passive differential standoff detection of surrogates. First, a brief description of the passive standoff detection principle together with the sensor hardware attributes for openair measurements are presented. This is followed by a description of the setup used to demonstrate the detection and identification of chemical pollutants. Finally, characteristics and results obtained with the newly developed sensors referred to as iCATSI FPA are presented. The overall analysis emphasizes the attributes of differential FTIR radiometry for passive standoff detection of chemical pollutants.