Vol 30, No 4 (2017)

FIRE-ARMS software was supplemented with the vector radiative transfer model VLIDORT. The new version of the software allows simulating outgoing thermal infrared radiation (TIR) from the Earth and solar shortwave infrared radiation (SWIR) reflected from the surface taking into account multiple scattering for the same atmospheric model and sensing geometry. We performed simulations of the spectra of outgoing TIR and SWIR radiation with multiple scattering in a cloudless atmosphere and compared them with the spectra measured by GOSAT satellite spectrometers in the cloudless atmosphere over Western Siberia. Analysis of calculated weighting functions shows that simultaneous use of the TIR and SWIR spectral regions will improve the height resolution in vertical profiling of methane concentrations in the atmosphere.

Eleven resonance functions are calculated in the exact trajectory model, which can be used for calculation of broadening coefficients γ of molecular lines during interactions with atoms of inert gases at very low temperatures. These functions correspond to the atom-atom potential and the potential V(R, θ) written in terms of Legendre polynomials. The functions are represented in analytical form. The broadening coefficients γ are calculated for absorption lines of CO perturbed by He and Ar at temperatures T from 300 to 2 K using the potential V(R, θ). It is shown that the dependence γ(T) for low temperatures T is determined by the potential well depth. For the CO–He system, a comparison with the experimental data is performed.

The spatial distribution and amplitude characteristics of the power absorbed inside multilayer particle-microcapsules, which consist of a liquid core and one or more polymer shells, is studied during changing the thickness and refractive index of the external shell; the position of the field localization is determined. This problem is important for the solution of practical tasks associated with opening the microcapsule shells in the appropriate spatial areas.

The conditions for filamentation of femtosecond pulse laser radiation when focusing in air are studied experimentally and theoretically. A good agreement between experimental and calculated results is shown if neglecting the filament plasma. It is shown that the Kerr nonlinearity plays a fundamental role in the generation, existence, and cessation of a filament at a small numerical aperture (NA ≤ 2.15 × 10^–3). The Kerr effect first leads to the beam self-focusing and generation of a filament, and at the final stage, to radiation defocusing and a sharp decrease in its axial intensity due to the beam wavefront distortions. In the case of aberration focusing, a spatial quasi-soliton is formed after a visible filament due to the balance between Kerr self-focusing and diffraction spreading. The quasi-soliton is a source of the directional white supercontinuum.

A description of the developed prototype of a remote detector of hazardous substance vapors based on a tunable ¹³С¹⁶О₂ laser is given. Results of test measurements of laser radiation transmission of organic liquid vapors (acetone, ammonia, ethanol, gasoline) are presented. The remote detection of acetone and ammonia vapors at distances up to 100 m is experimentally implemented.

The main factors leading to the increase in the intensity of coniferous forests focal drying in southern Siberia since the 1990s are analyzed. It is shown that a significant factor that weakens the resistance of coniferous trees could be long-term ozone depletion due to the permanent presence in the atmosphere of volcanic aerosols caused by frequent Plinian eruptions in the volcano tropical belt with VEI ≥ 4, which exposed southern Siberia to continuous exposure of high doses of short-wave UV-B radiation from 1992 to 2012.

We discuss the results of studying the physical-chemical composition of the atmospheric aerosol during expedition onboard the RV Akademik Nikolaj Strakhov carried out during winter of 2015–2016 on the route from Colombo to Kaliningrad (via Suez Canal). As compared to the Mediterranean Sea and Atlantic (near Europe), the atmosphere of the Arabian and Red Seas was characterized by higher values of most aerosol characteristics: 3–5 times larger aerosol optical depth (AOD), 4 times larger aerosol number concentration, 1.5 times larger concentrations of continent- and sea-derived ions, as well as more abundant gas admixtures (SO₂, HCl, HNO₃, NH₃). At the same time, two seas of the Indian basin substantially differ in aerosol composition, primarily due to outflows of aerosols of different types from the continents. The largest concentrations of black carbon (2.14 μg m^–3, on average), sea-derived ions (Na⁺, Cl^–, Mg²⁺), and NH₃ are observed over the Arabian Sea; larger values of the fine component of the AOD and concentrations of “continental” ions (SO₄^2-, Ca²⁺, NO₃^-, NH₄⁺) and gas admixtures SO₂, HCl, HNO₃ are found over the Red Sea. With respect to ion composition of aerosol, most stable concentrations are noted for Ca²⁺ ions (less than 15% difference among the seas), and maximal spatial variations are found for NH₄⁺ ions (the difference of up to a factor of 40).

Results of field experiments performed with bistatic optoelectronic communication systems in artificial and natural water reservoirs in 2015 are discussed. The experiments were aimed at estimation of the communication quality from the communication error probabilities and their standard deviations. Results of the experiments assume possibilities of creating optoelectronic communication systems capable of effectively operating in water and complex media (water–atmosphere and atmosphere–water, including ice interface) with communication line lengths from several tens to several hundreds of meters.

Knowledge of measurement errors is one of the most important issues for assessing the quality of experimental data. In this paper, we compared various methods and instruments for measuring the total ozone content (TOC) near St. Petersburg in the period from 2009 to 2015. We considered the TOC datasets of ground-based measurements at Voyeykovo (Dobson spectrophotometer and M-124 ozonometer) and Peterhof (Bruker 125HR spectrometer), as well as OMI and IASI satellite measurements. To assess the errors intrinsic to each of these instruments three ensembles of the TOC measurements were formed containing different numbers of comparisons and based on different selection criteria. At the first stage, we determined the means and standard deviations between the ensembles of the TOC measurements. Then, assuming a horizontally homogeneous and stationary ozone field, the random and systematic errors of individual methods were evaluated. The average random errors of the TOC measurements for all tree ensembles were 2.9 ± 0.5%, 2.8 ± 0.7%, 1.2 ± 0.2%, and 1.4 ± 0.1% for IASI, M-124, OMI, and Bruker 125HR, respectively. The systematic error of the standard Dobson measurements is–1.7% and–2.1% for OMI and IASI, respectively, and amounts to + 0.5% and + 2.1% for M-124 and Bruker 125HR, respectively. The OMI and Bruker 125HR TOC measurement errors are most resistant to atmospheric conditions, whereas errors in IASI and M-124 TOC measurements depend to a large extent on the state of the atmosphere.

The Millimetron space observatory with a 10-meter optical telescope is now being created in Russia; it is unparalleled in terms of the scale of scientific and technical problems to be solved in the study of objects in the Universe. The amount of information that can be received with this observatory largely depends on the chosen concept and manufacturability of technology that provide for the high quality of imaging by the telescope. Possible technical solutions and concepts that can form the basis for the creation of systems of adaptive correction of distortions of the incident radiation wavefront are considered based on the analysis of distorting factors. Versions of adaptive optics systems for the space telescope are considered and analyzed. The adaptation at the entrance pupil of the telescope is selected and substantiated, implemented with the circuit of parallel information reading by petals of the telescope integrated primary mirror. The circuit is suggested for real-time dynamic adjustment of the telescope adaptive control system by image analyzer signals. It is shown that visible radiation received from a field region shifted from the telescope optical axis with a random misalignment angle can be used as reference.