The construction and principle of operation of a imaging Fourier transform infrared spectroradiometer (FTIR spectrometer) equipped with a cooled 32-area photodetector designed for spectral analysis of open atmospheric paths are considered. The main technical characteristics of the Fourier spectrometer are reported. The technique of visualization of the detected vapor cloud is described. The results of field experiments using the imaging FTIR spectrometer are shown. Based on these results, the dynamics of motion of the cloud of material has been investigated, its angular and linear velocities have been estimated, and data on propagation of the cloud of material and change in its angular sizes in air have been obtained. A technique for analyzing data provided by two FTIR spectrometers is given, based on which one can estimate the size of the cloud and the distance to it from each device. It is shown that the results of detection of the cloud of material by the imaging FTIR spectrometer can be used to predict the propagation of material under study in space.
Рассмотрена конструкция и принцип действия панорамного инфракрасного фурье-спектрорадиометра. Приведены основные технические характеристики прибора.Описана методика визуализации обнаруженного облака паров вещества
This paper presents a portable Fourier spectroradiometer with resolution 8 cm(-1), operating in the 7-14-mu m range, with an MG-32 uncooled single-element pyroelectric photodetector. This Fourier spectroradiometer with uncooled photodetector is intended for remote determination of pollutant vapors in the open atmosphere, as well as for methane leaks on gas pipelines. (c) 2006 optical Society of America.
An algorithm based on a model of constancy of temperatures on the path and in a cloud of contaminants is proposed for solving the problem of identifying and determining contaminant concentrations by means of a Fourier spectroradiometer. The main problems of the procedure for processing the initial interferograms and the experimental spectra are considered, including those with small radiance contrasts of the paths. The experimental results of field tests of a spectroradiometer based on the proposed algorithm are presented. (C) 2004 Optical Society of America.
This paper discusses how the intrinsic background radiation of a Fourier spectroradiometer affects the results of the processing of two-sided interferograms. The operation of a Michelson interferometer is considered theoretically, and it is shown that, when objects with radiance temperatures close to the intrinsic temperature of the spectrometer are observed, inverted spectral sections and bands may appear in the final spectrum. The paper proposes an algorithm for correcting the initial interferograins and an experimental technique that makes it possible to eliminate the inversion of the spectrum and to compensate the intrinsic background radiation of the interferometer. (C) 2003 Optical Society of America.
The effect of background (instrumental) self-radiation of a Fourier transform infrared (FTIR) spectrometer on the processing of double-sided interferograms is studied. From a theoretical analysis of the Michelson interferometer it was shown that when the brightness temperature of the object of study is close to the temperature of the instrument, the measured spectrum may contain inverted spectral ranges or isolated bands. The interferogram correction algorithms and experimental technique for elimination of the spectrum inversion and for compensation of the background self-radiation of the instrument are suggested.