Imaging gases using Fourier transform infra-red(FTIR) techniques

摘要

The invention comprises an IR device 10 capable of collecting 8-14~m spectral region, an interferometer 12 capable of analysing the collected IR radiation in said region, imaging means 13 for imaging IR radiation emerging from the interferometer 12 onto an array of IR detectors 14. A computing means 16,18 obtains a plurality of IR spectra by performing Fourier transformations of the interferograms resulting from each IR detector and a display means 20 displays the IR image. The ambient temperature is measured (means not shown) as is the background temperature 16,18 and the difference in the two measurements is used to derive gas column densities from the IR spectra. The display means may also display the visible image of the area under investigation together with the IR image (figures 3 and 4 not shown).