Performance of a long-wave infrared Fourier Transform imaging spectrometer using a corner-cube Michelson interferometer and an uncooled microbolometer array

摘要

Interference imaging spectroscopy is the advanced subject among the infrared remote sensing, and it has become an important technique to detect spatial information and spectral information of targets. It has the advantages of high flux, high spectral resolution and high spatial resolution that can be used for detecting more details of the spectral and spatial information. Based on a Michelson interferometer with its mirrors replaced by corner-cubes, principles of a hand-held, static, long-wave infrared Fourier Transform(FT) imaging spectrometer using an uncooled microbolometer array are introduced. Because in such FT-based spectral imager, the interferogram is acquired over the whole field of the camera while the scene of interest scans the path difference range, vignetting should be strongly limited while keep the size of the interferometer as small as possible. Interferometer size is given and interferential light path is verified through TracePro software. First results of field and laboratory measurements using the spectral imager are presented. Remotely obtained spectrums collected with this instrument and with those of high precise Michelson spectrometer are compared, and the measured values turned out to be closely corresponded. The results, in turn, verified the feasibility of the systematic working mode. The resulting system tested here provides datacubes of up to 640×480 pixels over the 7.7～13μm spectral range, this wavelength range reveals important information about scenes such as gas or landmine detection, and the instrument has a spectral resolution of about 8cm~(-1) that fulfils the requirement for most targeted applications. Examples of sky and buildings detection are shown.