Greenhouse gases absorb the Earth’s thermal radiation and partially return it to the Earth’s surface. When accumulated in the atmosphere, greenhouse gases lead to an increase in the average global air temperature and, as a result, climate change. In this paper, an approach to measuring CO${}_2$ and CH${}_4$ concentrations using Fourier transform infrared spectroscopy (FTIR) is proposed. An FTIR spectrometer mockup, operating in the wavelength range from 1.0 to 1.7 $\mathsf{\mu }$m with a spectral resolution of 10 cm${}^{-1}$, is described. The results of CO${}_2$ and CH${}_4$ observations throughout a day in urban conditions are presented. A low-resolution FTIR spectrometer for the 16U CubeSat spacecraft is described. The FTIR spectrometer has a 2.0–2.4 $\mathsf{\mu }$m spectral range for CO${}_2$ and CH${}_4$ bands, a 0.75–0.80 $\mathsf{\mu }$m range for reference O${}_2$ bands, an input field of view of 10${}^{-2}$ rad and a spectral resolution of 2 cm${}^{-1}$. The capabilities of the 16U CubeSat spacecraft for remote sensing of greenhouse gas emissions using a developed FTIR spectrometer are discussed. The design of a 16U CubeSat spacecraft equipped with a compact, low-resolution FTIR spectrometer is presented.

In this work, we consider the models of cosmological inflation based on generalized scalar–tensor theories of gravity with quadratic connection between the Hubble parameter and coupling function. For such a class of the models, we discuss the correspondence between well-known versions of the scalar–tensor gravity theories and physically motivated potentials of a scalar field. It is shown that this class of models corresponds to the Planck observational constraints on the cosmological perturbation parameters for an arbitrary potential of a scalar field and arbitrary version of a scalar–tensor gravity theory. The spectrum of relict gravitational waves is analyzed, and the frequency range corresponding to maximal energy density is determined. The possibility of direct detection of the relic gravitational waves, predicted in such a class of models, by satellite and ground-based detectors is discussed as well.

The recovery of Raman spectra in the 800-1050-nm spectral range from a prototype static Fourier-transform spectrometer is described. Distortion effects introduced by the optical system of the static Fourier-transform spectrometer are studied. A method of correcting optical distortion is suggested. The proposed algorithm is tested using a monochromatic radiation source. A two-dimensional map of period distribution in the distorted interference pattern is plotted. A mapping that enables optical distortions of the two-dimensional interferogram to be corrected is proposed. The correction results are demonstrated by plotting interference fringe profiles. A comparison of various well-known phase correction methods in order to identify an optimal algorithm is presented. A matching criterion for the obtained spectra is proposed. Raman spectrum of a stilbene crystal obtained by a diffraction spectrometer with a resolution of δν = 14 cm-1 is used as a reference.

We have considered a technique for noncontact analysis of compounds and a device for its realization. To construct the device, we have proposed a static Fourier-transform spectrometer that is based on the phenomenon of interference in a wedge. A procedure for obtaining and processing emission spectra has been described. Interference patterns are recorded using sources of excitation radiation of 280 and 315 nm. Basic characteristics of the optical system have been calculated, and emission spectra of test objects have been presented.

The remote detection, identification, and determination of the presence of pollutants in an open atmosphere is one of the most important tasks of infrared (IR) spectroscopy. To solve this problem, it is proposed to use static IR-Fourier spectrometers, which, due to the absence of movable elements, are stable and small. The developed and created experimental layout of a static Fourier transform spectrometer (sFTS) for recording and analyzing gaseous compounds is described in this paper. To test the performance of the model, experiments are carried out to record and restore the IR absorption spectra of a test film simulator (lavsan) of the tested substances (methanol, ammonia) in the gas phase at a temperature contrast of 20°C and natural tests on an open route at a temperature contrast of 5 to 10°C. The results obtained confirm the possibility of using the developed sFTS layout for recording IR absorption spectra of chemical compounds in an open atmosphere.