This PDF file contains the front matter associated with SPIE Proceedings Volume 10466, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

The problem of radiative transfer in the ro-vibrational molecular bands under condition of local thermodynamic equilibrium breakdown in a planetary atmosphere is generalized for the case taking into account the extinction (i.e. scattering and absorption) of the continuum radiation produced by aerosols. The method for calculating the nonequilibrium populations of vibrational states of gas molecules in the planetary atmospheres is developed. Formation of the values of the non-equilibrium populations of the excited vibrational states of the CO₂ molecules (in the application to the atmosphere of Mars) within the framework of the model of radiative transfer in the near-infrared bands of this molecule taking into account the extinction of radiation in the continuum produced by aerosol particles has been investigated for the first time. The most complete optical model of the CO₂ and CO molecules is used. A distinctive feature of this model is the detailed accounting of the overlap in frequency of the lines in the spectral range of 1.05–15 μm, which belong to all ro-vibrational transitions of different isotopologues of the CO₂ and CO molecules included into the optical model, as well as accounting for the reflection of radiation by the surface of the planet.

The altitude profiles of ozone concentration are retrieved from measurements of the volume emission rate in the 1.27 μm oxygen band in the TIMED-SABER experiment. In this study we compare the methods of retrieval of daytime [O₃] altitude profile in the framework of two models: electronic-vibrational kinetics and a purely electronic kinetics of excited products of ozone and oxygen photolysis. In order to retrieve the [O₃] altitude profile from the measurements of the intensity of the O₂ band in the region of 1.27 μm correctly, it is necessary to use the photochemical model of the electronic-vibrational kinetics of excited products of ozone and oxygen photolysis in the mesosphere and lower thermosphere.

In this work the temperature dependences of the integrated intensities of the absorption bands of the asymmetric top molecules – H₂O, H₂S, SO₂, and NO₂ were analyzed. A different view of the temperature dependences was shown for cold bands including fundamental ones. For calculating the integrated intensities, the spectral line intensities were used from the known and author’s spectroscopic databases. The reasons are discussed which lead to increasing and decreasing the integrated intensities at high temperatures (T>300 K).

In this work the contributions from the hot bands in the total absorption of H₂S, SO₂, and NO₂ were calculated at temperatures of 300 – 1000 K. The high-temperature spectroscopic databases of the authors were applied for calculating the sum absorptions. The reasons of the different contributions from the cold and hot bands in the absorption spectra of the considered gases are discussed.

The study is dedicated to the problems of wavenumber calibration of multichannel Raman spectrometers. We present a calibration method based on the combined use of the neon emission spectrum and pure rotational lines of the hydrogen Raman spectrum.

The present work focuses on the influence of CH₄ environment on the changes in Raman spectra of n-C₅H₁₂ and i-C₅H₁₂ in the gaseous phase. It was found that in binary gas mixtures with an overwhelming content of CH₄, the majority of the n-C₅H₁₂ and i-C₅H₁₂ Raman bands shifted toward lower wavenumbers. Moreover, there is also a redistribution of intensities between certain Raman bands of n-C₅H₁₂ and i-C₅H₁₂. The obtained results will be essential for Raman diagnostics of natural gas composition.

The paper presents an original statistical algorithm for calculating the mean intensity of solar radiation in broken clouds I , taking into account the sphericity of the atmosphere. The algorithm is based on numerical averaging of the radiative transfer equation and introduction of an additional randomness (randomization). We discuss the results of numerical experiments, carried out to estimate the effect of statistics (numbers of cloud realizations and photon trajectories in a single realization) on the accuracy of the I calculations and laboriousness of the algorithm under different observation and illumination conditions.

The RKR potentials of six isotopologues of the hydrogen chloride molecule in the ground electronic state are calculated on the basis of previously determined values of the Dunham parameters Y_mj up to v = 20 vibration level. The main isotopologue potential was approximated by the expansions of the z_D = (r/r_e-1) and z_S = (1- r_e/r) variables. Obtained results are compared to available literature data.

Estimations of self-broadening, air-broadening and CO₂-broadening coefficients of the main isotopic modification of H₂S are performed. The result is presented as formulae describing the dependence of self-broadening, CO₂- broadening and air-broadening coefficients on rotational quantum numbers of the lower state of a transition. The comparisons of our estimated self-broadening coefficients values with those from the HITRAN and GEISA databases are presented.

Self-, CO₂-, N_2-broadened line widths of NO₂ molecule have been obtained at the room temperature for ~400 000 lines, rotational quantum numbers vary in the range: J to 70 и K_a to 20. The temperature exponents for every line were calculated. The data have been evaluated theoretically in the frame of two methods: semi-empirical approach based on analytical expressions and including a few-parameter correction to account for the real curved trajectories and averaged energy differences method. Being validated by comparison with measurements, these approaches were used to compute extensive line list which could be useful for atmospheric, astrophysical applications and spectroscopic databases.

Estimations of the effect of modern ozone absorption cros-ssections data on calculation of the atmospheric transmission and fluxes, measured using Sun photometers in the UV spectral region, are made. The ozone absorption cross-sections, often used in radiative codes, and new data of Serdyuchenko et al. are considered.

Small sets of chemical reactions involving four water monomers with real values of the rate constants and concentrations are discussed. The steady states and the molecular complex concentrations as functions of the total concentration and the rate constants of the reactions between dimers are examined. It is found that the concentrations of complexes in their approach to a steady state pass through a state with very slowly changing concentrations.

An approach is suggested to the formation of applied ontologies in subject domains where results are represented in graphical form. An approach to systematization of research graphics is also given which contains information on weakly bound carbon dioxide complexes. The results of systematization of research plots and images that characterize the spectral properties of the CO₂ complexes are presented.

The water vapor line broadening and shift coefficients of H₂O absorption lines induced by hydrogen pressure were measured using a Bruker IFS 125HR spectrometer.

The global fitting of the experimental energy levels of unresolved Λ-doublets for the ground state of ¹⁴N¹⁶O molecule is done. The dataset of 1789 experimental energy levels covering the 0-35665 cm^-1 interval for 23 vibrational states was obtained using the fundamental Rydberg-Ritz combination principle. A global model of analysis with vibrational dependences of the parameters of the effective Hamiltonian was used for the theoretical treatment of the diatomic molecule in ²Π electronic state. As a result of the fit a set of the "Dunham-type" molecular parameters was obtained. They reproduce the dataset of the experimental energy levels to the precision of the experimental ones. The found set of the parameters was compared with previous set determined by C.Amiot.

In the report a review is given and new results obtained at the IAO SB RAS on problems of optical communication on scattered laser radiation in the atmosphere and water media are presented. Examples of its implementation are presented under various optical-geometrical conditions and with high quality of field experiments at distances up to 70 km in the atmosphere and up to 25 m in the water medium.

The paper presents experimental data on electromagnetic radiation propagation at a frequency of 5.2 GHz through pine needles at negative temperatures. Hysteresis of electromagnetic losses under a temperature cycling in the range from -10 to -30°С is revealed. Variations in the signal power at the same temperature and mean attenuation of 3 dB reach 1.6 dB. This effect should be taken into account under remote sensing of coniferous forests in winter.

The results of the measurements of astroclimate characteristics in Special Astrophysical Observatory of RAS (SAO, North Caucasus) in 2012 and 2016 are presented. Experimental researches of turbulence structure in the dome specialized room of the Big Telescope Alt-Azimuthal (BTA) at the closed and open dome are executed. Research of distribution of velocities of the airflows movements in points on the volume of dome space is made and the experimental picture of air-flows is restored. Presence in the dome room of BTA of large vortex coherent structure that improves the images quality of the telescope is established.

The results of the measurements astroclimate characteristics in Special Astrophysical Observatory of RAS (SAO, North Caucasus) in 2012 and 2016 are presented. The results obtained from long-term series of observations of day and night astroclimate in SAO. Presence over the territory of the SAO of coherent turbulence in which the image quality of telescopes improves is established. The influence of the type of underlying surface and the direction of wind speed on the mode of appearance of coherent turbulence is found out. It was found that the reason for its appearance is the mountainous terrain and uneven heating of the underlying surface.

The structure of air turbulent motion inside the closed dome room of Big Telescope Alt-azimuth at Special Astrophysical Observatory of the Russian Academy of Sciences (RAS) has been experimentally and theoretically studied. Theoretical results have been reached by numerical solving of boundary value problem for Navier–Stokes equations. Solitary large vortices (coherent structures, topological solitons) are observed indoors. Coherent breakdown of these vortices leads to the coherent turbulence. In the case of identical boundary conditions the pattern of air motions as a result of the simulation and the pattern, registered experimentally using the compact portable ultrasonic weather station, are practically the same.

In the given article mean intensity of a fundamental Bessel-Gaussian optical beam in turbulent atmosphere is studied. The problem analysis is based on the solution of the equation for the transverse second-order mutual coherence function of a fundamental Bessel-Gaussian beam of optical radiation. Distributions of mean intensity of a fundamental Bessel- Gaussian beam optical beam in longitudinal and transverse to a direction of propagation of optical radiation are investigated in detail. Influence of atmospheric turbulence on change of radius of the central part of a Bessel optical beam is estimated. Values of parameters at which it is possible to generate in turbulent atmosphere a nondiffracting pseudo-Bessel optical beam by means of a fundamental Bessel-Gaussian optical beam are established.

According to the work plan for the RSF project, during 2016 measurements were taken in all seasons of the year: February, April, May, August and October. With the use of the whole set of equipment of the stand on the BSVT, the task was set to work out methods for recording and correcting the distortions of the phase of optical radiation passing through a layer of turbulent atmosphere. Complex on-site meteorological observations were organized and conducted at the site of the BSVT. Observations were carried out with the aim of developing and improving the local computational model of turbulent characteristics in the entire thickness of the active atmosphere in the "optical turbulence" range, including the surface layer. As the initial meteorological information for calculations, the model uses two-level data of pulsating observations of temperature and wind speed at the BSVT site, as well as current NCEP/NCAR archival data for the period from 1948 to 2015.

Simultaneous measurements of wave-front aberrations for coherent and incoherent radiation were carried out under conditions of urban atmospheric turbulence on a horizontal track measuring 103.9 m at an altitude of 10 m above the underlying surface. As a luminous object, a metal disk with a diameter of 12 mm was used with holes in which the luminous ends of the optical fibers were fixed.

Measurements of the wave front aberrations at the input aperture of the Big Solar Vacuum Telescope (LSVT) were carried out by a wave-front sensor (WFS) of an adaptive optical system when the controlled deformable mirror was replaced by a plane one.

In this article the coherence of a fundamental Bessel-Gaussian optical beam in turbulent atmosphere is analyzed. The problem analysis is based on the solution of the equation for the transverse second-order mutual coherence function of a fundamental Bessel-Gaussian optical beam of optical radiation. The behavior of a coherence degree of a fundamental Bessel-Gaussian optical beam depending on parameters of an optical beam and characteristics of turbulent atmosphere is examined. It was revealed that at low levels of fluctuations in turbulent atmosphere the coherence degree of a fundamental Bessel-Gaussian optical beam has the characteristic oscillating appearance. At high levels of fluctuations in turbulent atmosphere the coherence degree of a fundamental Bessel-Gaussian optical beam is described by an one-scale decreasing curve which in process of increase of level of fluctuations on a line of formation of a laser beam becomes closer to the same characteristic of a spherical optical wave.

In this work the question of stability of the vortex Bessel-Gaussian optical beams formed in turbulent atmosphere is theoretically considered. The detailed analysis of features of spatial structure of distribution of mean intensity of vortex Bessel-Gaussian optical beams in turbulent atmosphere are analyzed. The quantitative criterion of possibility of formation of vortex Bessel-Gaussian optical beams in turbulent atmosphere is derived. It is shown that stability of the form of a vortex Bessel-Gaussian optical beam during propagation in turbulent atmosphere increases with increase of value of a topological charge of this optical beam.

In this paper the theoretical research of coherent properties of the vortex Bessel-Gaussian optical beams propagating in turbulent atmosphere are developed. The approach to the analysis of this problem is based on the analytical solution of the equation for the transverse second-order mutual coherence function of a field of optical radiation. The behavior of integral scale of coherence degree of vortex Bessel-Gaussian optical beams depending on parameters of an optical beam and characteristics of turbulent atmosphere is particularly considered. It is shown that the integral scale of coherence degree of a vortex Bessel-Gaussian optical beam essentially depends on value of a topological charge of a vortex optical beam. With increase in a topological charge of a vortex Bessel-Gaussian optical beam the value of integral scale of coherence degree of a vortex Bessel-Gaussian optical beam are decreased.

The dynamics of turbulent characteristics including air index refraction vertical variations as well as effective turbulent velocity important for the functioning of the Large solar vacuum telescope (LSVT) adaptive optics system is considered. Long-term changes of the effective turbulent velocity and Fried radius in the atmospheric layer from 0 to 20 km are estimated using model of turbulence taking into account the shape of the energy spectrum over a wide range of spatial and temporal scales. The possible experimental local model of Fried radius changes is discussed for the Large solar vacuum telescope site.

The work discusses the spatial scales of atmospheric optical distortions including the outer scale of turbulence and the Fried radius. It is assumed that the energy spectrum of atmospheric turbulence is not limited strictly [6] and the outer scale is considered in application to astronomical telescopes. In the case when the telescope diameter is larger or comparable with the outer scale the optical distortions substantially differ from the results of the Kolmogorov model. For a given diameter it is possible to introduce a certain spatial scale at distances larger than the size of which the refractive index fluctuations no longer have a significant effect on the quality of astronomical images. Estimates of the outer scale of turbulence are reported for both a atmospheric layer from 0 up to 20 km and surface layer.

The resolution of an adaptive optics system consists in its ability to form and implement the control of a corrected wavefront with a given speed and within the finite range of spatial scales of random inhomogeneities of light field. In result of spatial and temporal limitations appear errors that is affect the efficiency of adaptive correction of turbulent distortions of optical radiation. On the basis of numerical experiments criteria were obtained criteria that allow to make estimated characteristics of all stages of adaptive correction.

The statistically optimal control algorithm for the correcting mirror is formed by constructing a prediction of distortions of the optical signal and improves the time resolution of the adaptive optics system. The prediction of distortions is based on an analysis of the dynamics of changes in the optical inhomogeneities of the turbulent atmosphere or the evolution of phase fluctuations at the input aperture of the adaptive system. Dynamic properties of the system are manifested during the temporary transformation of the stresses controlling the mirror and are determined by the dynamic characteristics of the flexible mirror.

To stabilize the image on the input aperture of the adaptive optics system, a model of the control device for the general angle of inclination of the wavefront is created. The device designed to eliminate image jitter due to atmospheric turbulence and the vibrations of the telescope itself makes it possible to control both the overall wavefront slopes at the input aperture of the system and the wavefront shift along the propagation axis of the beam. For testing the device, a program has been developed that simulates the angles of the wavefront inclination during the formation of an optical beam whose position at the input aperture of the adaptive system is unstable under the influence of atmospheric turbulence.

In this paper the results of simulation are presented of multichannel radiation propagation under conditions of thermal blooming, and correction for nonlinear thermal distortion on the base of the beam phase control is considered. The results demonstrate dependence of correction effectiveness on number of channels and on precision of a reference beam phase reconstruction. Addition increase of effectiveness is possible with adjustment of amplification in the channels of the optical system, i.e., with the use of amplitude-phase control of radiation..

Due to the fact that the cloudiness plays a critical role in the Earth radiative balance, the study of the distribution of different types of clouds and their movements is relevant. The main sources of such information are artificial satellites that provide data in the form of images. The most commonly used method of solving tasks of processing and classification of images of clouds is based on the description of texture features. The use of a set of local binary patterns is proposed to describe the texture image.

The problem of taking into account the effect of polarization is considered for correction of satellite images of the Erath’s surface in the visible wavelength range for the distorting effect of the atmosphere. A program complex for calculation of the radiation components forming the satellite images has been developed with and without allowance for radiation polarization in the approximation of the homogeneous surface. Conditions are considered under which the neglect of polarization properties of radiation can lead to significant errors in reconstruction of the reflection coefficients of weakly reflecting surfaces.

The report solves the inverse problem of diagnostics of inhomogeneous plasma through spatial field processing in the form of inverse double weighted Fourier transform (DWFT). As an inhomogeneous medium, we use a model in the form of three Gaussian irregularities. We examine the influence of dimensions of receiving-transmitting aperture system on diagnostic results.

The authors discuss problems of constructing a multi-site system for lightning activity monitoring aimed at analyzing the structure of tropical cyclones using a network of receivers of VLF radio signals. We propose a functional scheme for the construction of a monitoring system, which includes a functional block to synthesize the system structure, using the existing authorial multi-agent bio-inspired algorithm for synthesizing the sensor network structure.

Based on the numerical solution of the parabolic wave equation for the complex spectral amplitude of the wave field by method of splitting into physical factors the propagation of broadband pulsed optical beam taking into account absorption lines of atmospheric gases is studied. It is found that the influence of absorption lines on the propagation of short pulsed laser radiation whose spectrum coincides with the centers of strong absorption of the atmosphere spectrum in the intervals between weak absorption lines is insignificant.

The mean intensity, intensity fluctuations, and regular and random displacements of optical beams propagating through a zone of increased density formed at subsonic airflow about a turret in the turbulent atmosphere have been analyzed. It has been shown that the presence of perturbations around a turret due to the subsonic velocity of aircraft affects slightly the studied characteristics of the beam. Data illustrating changes in the studied beam characteristics for paths of different geometry and different turbulent conditions of radiation propagation are presented.

In this paper, an optical model of a shock wave is constructed, which is formed by the supersonic flow of air in the flowing of an ogival-shaped body. The average values of the gas flow parameters were calculated from the Navier- Stokes equations using the Fluent 6.0 package taking into account the compressibility of the gas. The results of numerical simulation of the propagation of a laser beam through a shock wave formed during supersonic flow around an ogival-shaped body are presented.

The double weighted Fourier transform method is used to find the average field, scintillation index, mutual coherence function, and intensity correlation in a randomly inhomogeneous multiscale medium. It is noted that the results obtained taking into account second-order effects are consistent with the results obtained with the path-integral method.

Based on numerical solution of the parabolic wave equation for the complex spectral amplitude of the wave field by method of splitting into physical factors the propagation of the superposition of broadband pulsed laser Laguerre- Gaussian beams in a turbulent atmosphere has been studied. It has been found that the difference in the energy density fluctuations of the axial superposition of several modes and one mode, the value of which is determined by the sum of the topological charge magnitudes, of pulsed Laguerre-Gaussian beams at the same turbulent conditions on the propagation path within the statistical error is the same.

Impulse response of non-line-of-sight atmospheric communication channels at wavelengths of 0.3, 0.5, and 0.9 μm are compared for the case in which the optical axes of the receiver and laser radiation lie in the plane perpendicular to the Earth’s surface. The most efficient communication channel depending on the base distance is determined. For a wavelength of 0.5 μm and a concrete variant of the transceiving part of the communication system, the limiting communication range and the limiting repetition frequency of pulses that can be transmitted through the communication channel are estimated.

Measurements of the distribution of probability density of fluctuations of the scattered radiation focused laser beam (0.63 μm) in the near-ground atmosphere in rain, drizzle and fog on the path length 130 m. It is established that the distribution of probability density unimodal and has a right skewness, standardized skewness and kurtosis increase with the growth of the scattering coefficient at close atmospheric conditions (with close values of the normalized variance and diameter (size) of the precipitation particles). The normalized skewness and kurtosis increase with the growth of the diameter (size) of particles of precipitation at close values of the coefficient of scattering. The shape of the distribution does not depend on the wind speed and its the perpendicular component to the path at close atmospheric conditions, at close values of the scattering coefficient. Most of the experimental distributions of probability density are approximated by a generalized gamma - distribution.

The transverse structure formation processes of a laser beam after multiple filamentation were investigated. It is shown that the spectra of post-filamentation light channels (PFC), rings and beam differ substantially. The spectrum of PFC has a significant and symmetrical spectral broadening and covers a range of 600-1100 nm. The broadening of the spectrum of the rings is asymmetric and is directed mainly to the short-wavelength region of the spectrum. The broadening data are stable and do not change when moving away from the multiple filamentation zone. The annular structure of radiation in the cross section of the beam is formed around individual filaments within the region of multiple filamentation, and at a distance of tens of meters from it begins to form a common ring structure surrounding postfilamentation channels.

The paper presents the results of the Helmholtz equation solution by the method of perturbation theory in the spherical coordinate system for the Debye potentials for weakly heterogeneous media based on metal nanoparticles and the dielectric matrix. In that case, the dielectric function of a composite changes in space in the radial direction.

According to the observations of VLF radiation in Kamchatka for the period from 1997 to 2017, radiation envelope periodograms at the frequencies of 0.7, 1.2, 5.3 kHz were obtained. The period of 1440 min was determined. It is caused by the Earth rotation around its axis relatively the Sun. Another period of 1436 min was also distinguished. It coincides with the Earth diurnal rotation relatively remote stars. The cause of the maxima occurrences at these periods may be the X-radiation of the Sun and the Galaxy. It was shown that VLF radiation intensity in the period range from 0.1 to 1000 days increases proportionally to the period logarithm and that the main and higher harmonics of diurnal frequency are observed in the radiation envelope spectra.

Among other things, artificial magnetically oriented irregularities are generated by the experiments on active impact on the ionosphere. They can be used for interlayer ionospheric waveguide excitation. We can suggest that the efficiency of waveguide excitation depends on mutual location of magnetically oriented irregularities and a feed element as well as on their topology in the interlayer ionospheric waveguide. To verify this hypothesis, electromagnetic radiation monitoring was applied in Kamchatka. The radiation was generated by the active impact on the ionosphere in Troms (Norway).

The paper represents experimental studying the scales of turbulent vortices in diffusion flames by using the measurements of thermodynamic characteristics obtained by thermography and the aerodynamic characteristics obtained by the PIV method.

The paper represents experimental studying the pulsations of temperature fields and the structure of a flow in the flame formed during the combustion of certain fuels. Also, the paper provides the mathematical modeling of a flow in the flame formed during the combustion of diesel fuels, as well as the comparison with experimental data and the estimation of the scale for turbulent vortices in flame. The experimental results are in satisfactory agreement with numerical modeling, which confirms the hypothesis of similarity for the pulsations of hydrodynamic and thermodynamic parameters.

The paper presents the results of a study of the backscattering enhancement factor (BSE) dependence of vortex LaguerreGaussian beams propagating on monostatic location paths in the atmosphere on optical turbulence intensity. The numeric simulation split-step method of laser beam propagation was used to obtain BSE factor values of a laser beam propagated on monostatic location path in the turbulent atmosphere and reflected from a diffuse target. It is shown that BSE factor of the averaged intensity of a backscattered vortex laser beam of any topological charge is less than BSE factor values of backscattered Gaussian beam in arbitrary turbulent conditions.

One tool to improve the performance of Monte Carlo methods for numerical simulation of light transport in the Earth’s atmosphere is the parallel technology. A new algorithm oriented to parallel execution on the CUDA-enabled NVIDIA graphics processor is discussed. The efficiency of parallelization is analyzed on the basis of calculating the upward and downward fluxes of solar radiation in both a vertically homogeneous and inhomogeneous models of the atmosphere. The results of testing the new code under various atmospheric conditions including continuous singlelayered and multilayered clouds, and selective molecular absorption are presented. The results of testing the code using video cards with different compute capability are analyzed. It is shown that the changeover of computing from conventional PCs to the architecture of graphics processors gives more than a hundredfold increase in performance and fully reveals the capabilities of the technology used.

Results of experimental and theoretical studies of the process of near-ground propagation of monochromatic acoustic radiation on atmospheric paths from a source to a receiver taking into account the contribution of multiple scattering on fluctuations of atmospheric temperature and wind velocity, refraction of sound on the wind velocity and temperature gradients, and its reflection by the underlying surface for different models of the atmosphere depending the sound frequency, coefficient of reflection from the underlying surface, propagation distance, and source and receiver altitudes are presented. Calculations were performed by the Monte Carlo method using the local estimation algorithm by the computer program developed by the authors. Results of experimental investigations under controllable conditions are compared with theoretical estimates and results of analytical calculations for the Delany–Bazley impedance model. Satisfactory agreement of the data obtained confirms the correctness of the suggested computer program.

Results of experimental studies carried out at the testing ground of the Basic Experimental Complex (BEC) of the V.E. Zuev Institute of Atmospheric Optics SB RAS in 2016 are reported. Statistical characteristics of jitter of video images of remote objects are analyzed. The possibility of estimating the path-integral structure characteristic of the refractive index at atmospheric paths by a passive optical method is demonstrated.

The paper deals with the simulation of such optical phenomena as halos, glories and coronas. To simulate these, we use the Monte Carlo method taking into account the multiple scattering of solar radiation. We have developed visualization software to represent computational results.

The paper presents the results of Monte Carlo simulation of the radiation regime in the system “atmosphere - water layer”. The radiation reflection and refraction at the sea surface is simulated with the help of the Fresnel formulas. The facet model is used to describe the sea surface roughness. The vertical stratification of the actinic flux, radiance and angular distributions of the solar radiation are investigated.

The quality of adaptive suppression of initial aberrations of the wave front of a main laser beam with the use of the method of aperture sensing by the signal of atmospheric backscattering of the additional (sensing) laser radiation at a different wavelength has been studied experimentally. It is shown that wavefront distortions of the main laser beam were decreased significantly during the setup operation.

The temporal evolution of width and shift of N I 746.8 and O I 777.4 nm lines is investigated in filament plasma produced by tightly focused femtosecond laser pulse (0.9 mJ, 48 fs). Nitrogen line shift is determined by joint action of electron impact shift and far-off resonance AC Stark effect. Intensive (I ~ 10¹⁰ W/cm² ) electric field of ASE and postpulses result in possible LS coupling break for O I 3p ⁵P level and generation of Rabi sidebands. The blue-shifted main femtosecond pulse and Rabi sideband cause the stimulated emission of N₂1⁺ system.

The paper presents the results of experimental studies of the acoustic field generated by a supersonic flooded jet on the wind tunnel of the Vertical Jet Unit (VJU) ITAM SB RAS. The submerged jet came out vertically upward into a large enough room. Measurements are made by 9 microphones, which are placed on a ring with a radius of 265 mm, which moved vertically. The microphone inputs are installed at a radius of 235 mm (through 36°) symmetrically with respect to the axis of the jet. The time spectra of the acoustic field and the shape of the phase front at npr = 5 at heights from -50 to 495 mm are considered. The Mach number in the output section was equal to unity.

Recently, due to the abundance of various types of observational data in the systems of vision through the atmosphere and the need for their processing, the use of various methods of statistical research in the study of such systems as correlation-regression analysis, dynamic series, variance analysis, etc. is actual. We have attempted to apply elements of correlation-regression analysis for the study and subsequent prediction of the patterns of radiation transfer in these systems same as in the construction of radiation models of the atmosphere. In this paper, we present some results of statistical processing of the results of numerical simulation of the characteristics of vision systems through the atmosphere obtained with the help of a special software package.¹

This paper analyses the feasibility of the remote sensing of the ¹³CO₂/¹²CO₂ isotopic ratio in the atmosphere using Thermal and Near-infrared Sensor for Carbon Observation-Fourier Transform Spectrometer/Greenhouse gases Observing SATellite (TANSO-FTS/GOSAT) measurements in the near infrared spectral range. We propose a spectral window with distinct ¹³CO₂ signatures and present retrieval error estimates for different sources of uncertainty such as: measurement noise, spectroscopy and a pirori profiles. We define main bottlenecks in the retrieval and discuss if such methods can be used to monitor local changes and detect global trends of the isotopic CO₂ ratio in the atmosphere.

Dependence of filamentation thresholds were investigated as well as filamentation special spread and supercontinuum generation concerning concentration of chlorophyll A photosynthetic pigment. Energy thresholds of filamentation origin were identified in sea water samples. It was observed that rise of chlorophyll A concentration led to rise of filamentation origin threshold. As chlorophyll A concentration rise the efficiency of radiation transformation reduces (radiation of basic harmonic of titan-sapphire laser onto supercontinuum spectrums in wave length range from 420nm to 680 nm).

The spectral bands shape of sea water Raman scattering and laser induced fluorescence of chlorophyll A were experimentally investigated when scattering and fluorescence induced by the different wavelength and duration of laser radiation. The femtosecond laser pulses with 400, 480, 500 nm of wavelength, nanosecond impulse (532 nm) and continuous laser radiation (527 nm and 400 nm) were used in these experiments. The spectral line shape of the sea water Raman scattering is Gauss function corresponding to the symmetrical vibrations (ν₁) when femtosecond laser pulses were used. Maxima corresponding to the Fermi resonance (2ν₂) and antisymmetric vibrations (ν₃) were not detected.

The problem of diffusion of the two parallel rays within oblique propagation in a linear layer containing isotropic random inhomogeneities of the dielectric permittivity is considered. Based on the stochastic ray equations written in the coordinate system of the parabolic cylinder, the coefficients of the equation of Einstein-Fokker, describing the relative diffusion of the rays, are defined. The distribution law of the relative fluctuations of the directions of rays for the case when the initial distance between the rays is much greater than the radius of correlation of fluctuations of the dielectric permittivity, is obtained. It is shown that the distribution in the coordinate system used is valid in any point of the trajectory of the rays, which coordinates satisfy the conditions of the problem considered.

The problem of correct ion and electron temperatures yielded on Irkutsk Incoherent Scatter Radar (IISR) is actually prominent. The existing algorithms of temperatures reconstruction on the IISR data counts out some constructive peculiarities of the radar, what can lead to increase of systematic errors. The obtained height and time profiles of ion temperatures do not suffice the ones expected on the basis of comprehensive concepts and experimental data of other facilities (e.g. Millstone Hill Incoherent Scatter Radar). The Faraday Effect on height power profile of the backscattered signal is assumed to be the key factor of this discrepancy. Allowance for this effect results in considerable complication of the inverse problem. In the present paper, the technique for systematic error estimation and correction based on direct model of backscattered signal was proposed.

The airborne hyperspectral (HS) systems for geomonitoring from board of unmanned aerial vehicles (UAV) use special modes of collection, transmission and processing of HS information. We suggest that autonomous mode can be realized on the base of real-time on-board information processing by means of spectral imaging. We demonstrate that such systems based on aberration-compensated pair of acousto-optical tunable filters (AOTF) satisfy most of the requirements for UAV HS system. The operation principle, characteristic features and prospects of the developed HS imaging system are described.

Micro pulse lasers have allowed solution of some technical problems and design of a specialized aerosol lidar capable of recording backscattering amplification (BSA) in a turbulent atmosphere (2014) by now. The BSA-lidar has two receiving channels, one of which is affected by a turbulence. The measurement result is the ratio of echo signals, i.e., the coefficient of backscattering amplification. The problem of lidar data inversion and retrieval of “optical” turbulence parameters was recently solved by V.V. Vorob’ev theoretically (2016). A lidar experiment was organized for testing the solution, and the asymptotic solution was applied to echo signals, which allowed estimating the daily behavior of the structural characteristics C_n ² along a horizontal 2-km path. The experiment was accompanied by parallel independent measurements of C_n ² by an image jitter sensor along the same path. It was shown experimentally that the Vorob’ev solution is applicable to C_n ² retrieval from BSA-lidar data if β₀ ²≤3; for β₀ ²>3, the saturation of the amplification effect and a decrease in the experimental data with respect to calculation results are observed. The coefficient of correlation between the retrieved structural characteristics C_n ² of the lidar and jitter sensor is 0.8–0.9. The C_n ² values retrieved from lidar signals turned out to be 20–40% lower than the C_n ² values of the image jitter sensor.

A specialized aerosol lidar has been designed at Institute of Atmospheric Optics SB RAS for remote sounding of atmospheric turbulence. The lidar records aerosol backscattering amplification (BSA) in the turbulent atmosphere. An image jitter sensor (IJS) was manufactured for automated monitoring of turbulence along a path; it allows estimation of the mean intensity of atmospheric temperature turbulence along a horizontal 2-km path. The results of simultaneous operation of BSA-2 lidar and IJS under weak atmospheric turbulence are described. They were used for estimation of the turbulent lidar sensitivity. It was noted that IJS readings of the variance of image jitter differ in horizontal and vertical directions under a weak turbulence. An increase in the vertical component of the jitter variance was caused by some slow atmospheric processes or convection near an IJS target, which did not affect the lidar data.

The kinetic model of radiation transfer, based on the non-stationary transfer equation, is considered. The explicit solution of the inverse problem, which consists of determining the volume scattering coefficient in a weakly scattering medium, is obtained in the single-scattering approximation and point-pulse source, when the dimensions of the diffusers are comparable with the scale of sensing. The solution of the direct problem for determining the received signal considering two-fold volume scattering is obtained. Analysis of the adequacy of the solution in the single-scattering approximation is carried out.

The sensitivity of satellite thermal infrared hyperspectrometer readings to variations of the atmospheric gas constituent amounts is considered. It is shown that the differential sensitivity coefficients of the instrument channels to variations in the density of the gas of interest is expressed through the mass absorption coefficient of this gas and an universal function which is determined by the intensities of the outgoing radiation for the unperturbed atmosphere. The numerical values of the universal function, as well as the methane and ozone differential sensitivity coefficients for the AIRS/Aqua channels, obtained with the use of Line-By-Line Radiative Transfer Model, are presented.

For a vortex axisymmetric Airy beam, the second-order mutual coherence function for the complex amplitude of the wave field was calculated by two methods. The first method assumed previous calculation of the complex amplitude of wave field of the beam in a turbulent medium based on the Monte Carlo technique, while the second method used the well-known representation of the solution of equation for the second-order spatial coherence function. Coherent properties of the beam at different values of parameters are studied.

In this paper the theoretical analysis of the light-induced mass transfer in the dispersed liquid medium was carried out for large intensities of the Gaussian beam radiation, when the concentration is greater than or comparable to the primary. The non-linear lens in this mode increases exponentially with the intensity of the light. The results are relevant in the study of the radiation self-action in dispersed liquid media, as well as optical diagnostics of such materials, including the thermo-spectroscopy.

Based on the mathematical model of the propagation of an acoustic signal in a fluctuating medium, the inverse problem is formulated, which includes determination a function that describes the deviation of the bottom level from the average specified horizontal plane. In the single-scattering approximation and the narrow directivity pattern of the receiving antenna, the solution of the direct problem is obtained. As a solution to the inverse problem, a nonlinear differential equation is obtained for a function describing the deviation of the bottom relief. A numerical analysis of the solution of the equation is carried out. The dependence of the reconstruction of the lower surface on the curvature of the function describing the relief is shown.

The functional expansion of the operating model of a slightly inclined lengthy atmospheric path is described. The experimental setup contains the module of signal beam profile control, the module of a path state active meteooptic control and the module of a beam inclination adaptive correction. The testing results for the designed hardware-software complex under the on-line monitoring of dynamic and stochastic optical parameters of the path are presented. The spatial anisotropy of stochastic and dynamic parameters of the path and the beam was investigated experimentally. The tests of hardware-software adaptive control module for the beam energy center control were carried out using a combination of proportional, integral and differential correction algorithms with the demonstration of the response anisotropy on adaptive impact.

The cross-sections of attenuation, scattering and absorption of spherically aggregated metal nanoparticles in dependence on the aggregate size, the degree of its filling with nanoparticles and physical properties of nanoparticle material have been estimated, according to the model of the effective medium and the theory of G. Mie. In that case, the concentration of the nanoparticles changes radially.

The results of development the automated system of two-dimensional diagnostics of defects of crystalline materials are presented. Used technology imaging. The structural scheme of the system is given, its main blocks are indicated, the approbation process is described, the software of the system is described.

The issue of fast recognition of marine particles in situ by digital holography methods is considered. An algorithm for the classification of marine particles by morphological features is proposed. Preliminary results and estimation of accuracy of the proposed algorithm are presented.

Optical scheme of three-stage converter of middle IR range laser radiation to the terahertz (THz) radiation of range is proposed. In the first cascade the 2-micron emission in Ho:YAG laser is generated. In the second cascade it is supposed using frequency conversion of radiation of the Ho:YAG laser in ZnGeP₂ single crystal to radiation with a wavelength of ~ 4-4.5 μm, and in the second cascade it is expecting of using parametric frequency conversion of the two parametric sources ~ 4-4.5 μm range to the THz range by generating radiation of difference frequency in the nonlinear optical crystal ZnGeP₂. Estimation of the characteristics of the output terahertz radiation is given in this paper.

At the moment, methods of sounding a status of soil, plant, forest and aquatic environments using radiometry and radar methods are intensively used. The main source of information using radar sounding is the back reflection ratio. The radiometric method is used for detection of the brightness temperature. In this paper, a communication between the back reflection ratio and the brightness temperature is described. This communication is proportional.

The profound research and physical applications of interactions of different types of waves with medium are very important. Particularly the most interesting sphere is for complex environments, which may be characterized by the increasing number of methods. Their objective analysis increased because of great applied significance. For the optical range it comes to considering the structure, the dimensions of the spatial inhomogeneity of which are comparable to the wavelength of the radiation.

Results of complex experiments, in which flows of solar radiation are measured near the Earth’s surface in the presence of cirrus cloudiness and the orientation degree of ice crystals in cirrus is estimated using a polarization lidar, are discussed. Significant effect of the orientation degree of cirrus particles on the transmission of solar radiation is found in a number of experiments.

The current state of the problem of light scattering by ice crystal particles of cirrus clouds is presented for the problem of interpreting the lidar signal. A short overview of existing methods and approaches to the solution of the problem of light scattering by nonspherical particles is presented. The results obtained within the framework of the physical optics approximation agree well with the results of experimental observations and can be used to interpret lidar data. The solution of the light scattering problem is available as a data bank of the Mueller matrices.

By the present a large amount of data has been accumulated on direct measurements of the pollution and thermodynamic state of the atmosphere in the Moscow region, which was obtained at stations of Roshydromet, Mosecomonitoring, A.M.Obukhov Institute of Atmospheric Physics (OIAP), M.V. Lomonosov Moscow State University, NPO Typhoon, what allows estimating pollution emissions based on measurements and correcting existing emission inventories, which are evaluated mainly on indirect data connected with population density, fuel consumption, etc. Within the framework of the project, the whole volume of data on the concentration of ground contaminants CO, NOx, SO2, CH4, obtained at regularly operated Moscow Ecological Monitoring stations and at OIAP stations from 2005 to 2014, was systematized. Observation data on pollution concentrations are supplemented by measurements of their integral content in the atmospheric boundary layer, obtained by differential spectroscopy methods (MAX DOAS, ZDOAS) at stationary stations and by passing Moscow with DOAS-equipped car. The paper present preliminary estimates of pollution emissions in the Moscow region, obtained on the basis of the collected array of experimental data. The estimations of pollutant emissions from Moscow were obtained experimentally in a few ways: (1) on the basis of network observations of surface concentrations, (2) on the basis of measurements in the atmospheric layer 0–348 m at Ostankino TV tower, (3) on the basis of the integral pollutant (NO2) content in ABL obtained by DOAS technique from stationary stations, and (4) using a car with DOAS equipment traveling over the closed route around Moscow (for NO2). All experimental approaches yielded close values of pollution emissions for Moscow. Trends in emissions of CO, NOx, and CH4 are negative, and the trend of SO2 emission is positive from 2005 to 2014.

In 2004-2015, along the route of the Russian Antarctic Expeditions in the East Atlantic, we performed annual measurements of aerosol parameters: number concentrations of small (d = 0.4-1 μm) and large (d > 1 μm) particles, mass concentrations of aerosol and black carbon, atmospheric aerosol optical depth (AOD), and its fine- and coarse-mode components. The obtained data allowed us to reveal the regularities of latitudinal (with 5° step) distribution of aerosol parameters and create the prerequisites for their zoning. In the work, the latitudinal boundaries of the identified regions are estimated. To estimate the longitudinal boundaries of the aerosol regions, we employ multiyear (2002-2015) data of satellite (MODIS/Aqua&Terra) measurements of atmospheric AOD.

The methods of determination of concentration and scattering by suspended particles in seawater are compared. The methods considered include gravimetric measurements of the mass concentration of suspended matter, empirical and analytical calculations based on measurements of the light beam attenuation coefficient (BAC) in 4 spectral bands, calculation of backscattering by particles using satellite measurements in the visible spectral range. The data were obtained in two cruises of the R/V "Professor Vodyanitsky" in the deep-water part of the Black Sea in July and October 2016., Spatial distribution of scattering by marine particles according to satellite data is in good agreement with the contact measurements.

The results of measurements of the aerosol optical depth (AOD) of the atmosphere carried out in 66th and 67th cruises of RV “Akademik Mstislav Keldysh” (Kara and Barents Seas) and at Russian scientific center in Barentsburg (Svalbard) during polar summer of 2016 are analyzed. It is shown that the level of aerosol turbidity of the atmosphere was close to the long-term average data in arctic latitudes. The mean value of AOD(0.5 μm) obtained from shipborne measurements is 0.065±0.056 and analogous value in Barentsburg is 0.072±0.040. The smoke plumes of forest fires on the continent significantly affected the atmospheric turbidity during measurements. For example, the contribution of smoke aerosol in the mean value of AOD (0.5 μm) obtained onboard the ship is about 44%.

The main objective of this research is to study the interannual variability of the Black Sea chlorophyll-a concentrations related to the forcing of physical factors (SST, wind, sea circulation) and/or influence of climate variability. The Self-Organization Map (SOM) analysis was applied to identify typical (recurrent) spatial patterns of chlorophyll-a concentrations and physical forcing data. The results of SOM analysis are compared with temporal variability of the climatic indices (NAO, EAWR). The propagation of desalinated water through Danube delta along the Western Black Sea coast and the hydrological structure of shelf water are studied. The dynamics, the coastal current, and formation of Danube plume and salinity front are studied on the basis of numerical modeling which was adapted to the conditions of the North-Western shelf. The results of numerical modeling of effects of plume and buoyancy current evolution, shelf water stratification and wind forcing for summer period conditions are discussed. As a result, the model gives qualitatively correct position of salinity front related with Danube discharge, plume and alongshore current evolution.

The vertical profiles of aerosol and BC concentrations measured in flights of the aircraft-laboratory of IAO SB RAS in cloudless troposphere in 2000-2016 near the village of Zav’yalovo (Novosibirsk Oblast) are analyzed. The temporal dynamics of the annual average aerosol concentration is characterized by a weak linear trend from -0.04% a year at a height of 0.5 km to -1.3% at 7 km. In 2010, minimal BC concentrations were observed at all heights. The decrease of the BC concentration in 2000-2010 (-3.6÷-10%) and its increase in 2010-2016 (+4.8÷25%) have led to the situation that the BC trend became positive for the entire period of observations: +2.6÷5.3%. The year-to-year variations of the seasonal average aerosol and BC concentrations before and after 2010 have been estimated. It is shown that the differences in the seasonal average vertical profiles of the aerosol and BC concentration for the intervals of 2000-2008 and 2000-2016 are statistically insignificant.

A method allowing to obtain estimates of dissolved organic and suspended matter content in Black Sea waters using beam attenuation coefficient (BAC) measurements in two spectral channels is proposed. It makes possible to assess the composition, bio-productivity and ecological state of waters in real time, and to validate the data of satellite scanners. The method is based on retrieval the spectral distribution of BAC by orthogonal functions. Full spectral distribution in range 416 – 677 nm allows to select spectral sites with a dominant contribution of certain substance in BAC and to obtain the content of yellow substance and suspended matter using specially designed optimization technique. Calculated values are in good agreement with the satellite data obtained from MODIS scanner.

Since January 2013, observations of atmospheric transparency in the wavelength range of 0.34–2.14 μm have been conducted at the Antarctic Mirny observatory, which are used to determine the aerosol optical depth (AOD) and water vapor content of the atmosphere. In this work, the results of five-year cycle of measurements of spectral AOD of the atmosphere in the Antarctic region are summarized: we present statistical characteristics, and estimate the seasonal and interannual variations and interrelations with meteorological parameters. Comparison with data, obtained earlier in this region, showed that aerosol turbidity remains at stably low level during two recent decades: the average AOD value at the wavelength of 0.5 μm is 0.026±0.011.

The results of the round-the-clock measurements of the size distribution of equivalent black carbon in the near-ground submicron aerosol of Western Siberia in 2014-2016 are analyzed. The results were obtained with the diffusion BC spectrometer developed by us. It was found that, in the approximation of unimodal lognormal function, the annual dynamics of the monthly average BC size distributions is characterized by the year-to-year stability and shows winter maxima and summer minima of the BC volume median diameter and the distribution amplitude. The BC median diameter varies from 140 to 220 nm, and the distribution amplitude ranges from 0.4 to 3.4 μm³/cm³. A significant increase in the diurnal average values of the BC median diameter was observed under conditions of income of smokes from forest fires to the measurement site.

Characteristics of light scattering in sea water depend on the concentration and composition of suspended particles. There are a number of methods for solving inverse problems of determination of suspended matter composition from light scattering phase functions. In this work number and mass concentrations of total suspended matter and its specific size fractions in the waters of major currents of North Atlantic tropical region (NATR) are determined using these methods. The concentration and fractional composition of suspended matter differ significantly in the areas of upwelling and downwelling of water. All parameters is higher in the upwelling areas. The characteristics and variability of suspended matter in areas of upwelling and downwelling were found to be similar in Atlantic tropical water, Mediterranean Sea and Indian tropical water.

A numerical model of a multicomponent gas-aerosol medium designed for studying the transmission function in the visual and IR ranges has been proposed. Taking into account the molecular absorption by the gas component and also the light scattering and absorption by the aerosol, the radiation extinction is determined. To calculate the optical characteristics of a dispersed component, the Mie theory is applied. Methane is selected as the main gas component of the medium. The separate and combined contributions of molecular absorption and aerosol extinction to the transmission of optical radiation by a gas-aerosol medium are analyzed.

The results of atmospheric aerosol monitoring are discussed. We compare data of particle size distribution function, which are obtained by photoelectric counter, with inversion of data closed volume aureole photometer, that’s allow us to measure the aureole scattering phase function in the range of angles 1.2-20 degrees at a wavelength of 650 nm. Seasonal variations and inter-annual differences collected from 2010 to 2015 years are analyzed and evaluated.

A gas-disperse mixture sampled from the near-ground atmosphere into a closed volume (1800 m³) of the Big Aerosol Chamber (BAC) was subjected to long irradiation by an ultraviolet lamp (DRT-1000). As a result of irradiation, the increased concentration of ozone was formed in BAC and the fine fraction of aerosol particles with the size r < 80 nm was intensely generated. In the course of the experiment, a spectronephelometer measured current values of the polarization components of the directed scattering coefficient β⊥,||(λ_i, θ_j). The time series of β⊥,||(λ_i, θ_j, t_k) measured by the polarization nephelometer at four wavelengths λi = 455, 525, 585, 630 nm and five scattering angles θ _j= 15, 45, 110, 135, 165° were used for numerical solution of the inverse problem of aerosol scattering. The evolution of the size spectrum of aerosol particles in the fine fraction with r < 200 nm has been traced.

Estimates of wind speed and direction obtained from measurements of the radial velocity by a pulsed coherent Doppler lidar with the duo-beam method and the method of conical scanning have been compared experimentally. The obtained experimental results are compared with data of a point meter of wind velocity – acoustic weather station.

Experimental investigations of different factors influencing on stability of laser induced fluorescence spectra of plants were conducted for 532 nm wavelength of fluorescence excitation. The experimental setup was described and processing results of laser induced fluorescence spectra of plants were presented. Stability of the fluorescence intensity ratio R at wavelengths of 685 and 740 nm versus type of soil, and wide variance of the R ratio for different plants were demonstrated.

Spatiotemporal dynamics of the standard deviations of three wind velocity components measured with a mini-sodar in the atmospheric boundary layer is analyzed. During the day on September 16 and at night on September 12 values of the standard deviation changed for the x- and y-components from 0.5 to 4 m/s, and for the z-component from 0.2 to 1.2 m/s. An analysis of the vertical profiles of the standard deviations of three wind velocity components for a 6-day measurement period has shown that the increase of σ_x and σ_y with altitude is well described by a power law dependence with exponent changing from 0.22 to 1.3 depending on the time of day, and σ_z depends linearly on the altitude. The approximation constants have been found and their errors have been estimated. The established physical regularities and the approximation constants allow the spatiotemporal dynamics of the standard deviation of three wind velocity components in the atmospheric boundary layer to be described and can be recommended for application in ABL models.

The article considers the problem of control and verification of the laser ceilometers basic performance parameters and describes an alternative method based on the use of multi-length fiber optic delay line, simulating atmospheric track. The results of the described experiment demonstrate the great potential of this method for inspection and verification procedures of laser ceilometers.

The distributions of impurities obtained as a result of numerical modeling on the Srednyaya arm (Selenga River mouth)– Cape Golyi cross-section of Lake Baikal, Siberia, Russia, are presented. The data on the air temperature, relative humidity, atmospheric pressure, humidity, and cloudiness from the Babushkin meteorological station from 01.06.2016 to 30.06.2016 are used as the weather condition in the mathematical model. The results of simulation have shown that the impurities dissolved in water reach the bottom of the Selenga shallow basin of Lake Baikal. As the heat accumulation increases and the river waters warm up, the maximum concentrations of suspended substances tend to remain in the upper layers of the lake.

The results of lidar study of wind turbulence, low level jet streams, and internal atmospheric waves in the stable boundary layer of atmosphere on the coast of Lake Baikal are presented. Few events of the atmospheric internal waves (AIWs) were registered during the experimental campaign. All the registered AIWs were observed in the presence of low level jet streams. Two dimensional time–height patterns of the wind turbulence dissipation rate during AIW events were obtained as well.

The accuracy of the method of azimuth structure function for estimation of the dissipation rate of the kinetic energy of turbulence from an array of radial velocities measured by low-energy coherent Doppler lidars with conical scanning by a probing beam around the vertical axis has been studied numerically. The domain of applicability of the method has been determined for different levels of the turbulence intensity and the signal-to-noise ratio.

Results of comparative experiments on measurement of the cross (with respect to the given direction) wind by the correlation method with the prototype of an optical wind meter developed in the IAO SB RAS and the StreamLine coherent Doppler wind lidar are presented.

Three satellites of the Resurs-P series (№1, №2, №3) aimed for remote sensing of the Earth began to operate in Russia in 2013-2016. Hyperspectral instruments GSA onboard Resurs-P perform routine imaging of the Earth surface in the spectral range of 400-1000 nm with the spectral resolution better than 10 nm and the spatial resolution of 30 m. In a special regime the GSA/Resurs-P may reach higher spectral resolution with the spatial resolution of 120 m and be used for retrieval of the tropospheric NO2 spatial distribution. We developed the first GSA/Resurs-P algorithm for the tropospheric NO2 retrieval and shortly analyze the first results for the most polluted Hebei province of China. The developed GSA/Resurs-P algorithm shows the spatial resolution of about 2.4 km for tropospheric NO2 pollution what significantly exceed resolution of other available now satellite instruments and considered as a target for future geostationary (GEO) missions for monitoring of tropospheric NO2 pollution. Differ to the currently operated low-Earth orbit (LEO) instruments, which may provide global distribution of NO2 every one or two days, GSA performs NO2 measurement on request. The precision of the NO2 measurements with 2.4 km resolution is about 2.5x10¹⁵ mol/cm² (for DSCD) therefore it is recommended to use it for investigation of the tropospheric NO2 in polluted areas. Thus GSA/Resurs-P is the interesting and unique tool for NO2 pollution investigations and testing methods of interpretation of future high-resolution satellite data on pollutions and their emissions.

An instrument for measuring atmospheric trace gases by DOAS method using scattered solar radiation was developed in A.M.Obukhov IAP RAS. The instrument layout is based on the lab Shamrock 303i spectrograph supplemented by 2-port radiation input system employing optical fiber. Optical ports may be used with a telescope with fixed field of view or with a scanning MAX-DOAS unit. MAX-DOAS unit port will be used for investigation of gas contents and profiles in the low troposphere.

In September 2016 the IAP instrument participated in the CINDI-2 campaign, held in the Netherlands. CINDI 2 (2^nd Cabauw Intercomparison of Nitrogen Dioxide Measuring Instruments) involves about 40 instruments quasi-synchronously performing DOAS measurements of NO₂ and other trace gases.

During the campaign the instrument ports had telescopes A and B with similar field of view of about 0.3°. Telescope A was always directed to the zenith. Telescope B was directed at 5° elevation angle. Two gratings were installed in the spectrometer. They provide different spectral resolution (FWHM ~0.4 and 0.8 nm respectively) and spectral window width (~70 and ~140 nm respectively). During CINDI-2 campaign we performed test measurements in UV and visible wavelength ranges to investigate instrument stability and retrieval errors of NO₂ and HCHO contents.

We perform the preliminary error analysis of retrieval of the NO₂ and HCHO differential slant column densities using spectra measured in four modes of the instrument basing on residual noise analysis in this paper. It was found that rotation of grating turret does not significantly affected on quality of NO₂ DSCD retrieval from spectra which measured in visible spectral region. Influence of grating turret rotation is much more significant for gas DSCD retrieval from spectra which measured in UV spectral region. Standard deviation of retrieval error points to presence of some systematic error.

General features of forming lidar returns for sensing of depth profiles of the optical characteristics of sea water comprising pelagic fish schools are considered. Based on the data of statistical simulation by the Monte Carlo a method, an algorithm of analysis of two polarization components of lidar returns has been developed in which the threshold value is the signal from the surrounding water mass with the known light scattering properties.

Laser induced fluorescence is a powerful tool for remote detection and classification of oil pollutions. Mathematical modeling of oil pollution detection and classification was conducted on the basis of fluorescence spectra obtained experimentally. Dependence of oil pollutions classification accuracy versus the number of spectral channels is investigated.

The application of robust methods of statistics to processing of data of minisodar measurements of vertical profiles of three wind velocity components at altitudes 5–200 m is considered in the report. The statistical characteristics of three wind velocity components obtained using nonparametric methods based on the weighted maximum likelihood method and classical methods are analyzed. Results of minisodar data processing showed that the standard methods of processing lead to considerable bias and low efficiency of estimations in comparison with the nonparametric WMLM estimations.

The formulae and results of calculation of the spatiotemporal structure function of intensity in the optical image of a topographic object in a turbulent atmosphere are presented. The results can be used in development of algorithms for estimation of the crosswind velocity from optical images of natural scene.

By the beam attenuation measurements in the photic layer of the Black Sea the total suspended matter (TSM) content was calculated. The main features of the TSM spatial distribution were identified. The relationship between the TSM vertical distribution and the thermohaline structure is shown.

The results of measurements of parameters of aircraft wake vortices by a Stream Line coherent Doppler lidar during the three-day experiment on the airfield of Tolmachevo Airport are presented. We have analyzed spatial dynamics and evolution of the wake vortices generated by aircrafts of various types: from the Airbus A319 passenger aircraft to the heavy Boeing B747-8 cargo aircraft entering the landing at Tolmachevo Airport. It is shown that the Stream Line lidar may well be used to obtain reliable information about the presence and intensity of aircraft wake vortices in the vicinity of the runway.

The article deals with assessment of anthropogenic pollution in vicinity of local boilers using the data on microelement composition of solid airborne particles deposited in snow. The anthropogenic feature of elevated accumulation levels of solid airborne particles deposited in snow in the vicinity of coal-fired boiler house is revealed in elevated concentrations (3-25 higher than background) of Cd, Sb, Mo, Pb, Sr, Ba, Ni, Mo, Zn and Co. In the vicinity oil-fired boiler house the specific elements as parts of solid airborne particles deposited in snow are V, Ni and Sb, as their content exceeds the background from 3 to 8 times. It is determined that the maximum shares in non-carcinogenic human health risk from chronic inhalation of trace elements to the human body in the vicinity of coal-fired boiler house belong to Al, Mn, Cu, Ba, Co, Pb, whereas in the vicinity of oil-fired boiler house – Al, Mn, Cu, Ni, V.

The data bank for the backscattering matrixes of cirrus clouds that was calculated earlier by the authors and was available in the internet for free access has been replaced in the case of randomly oriented crystals by simple analytic equations. Four microphysical ratios conventionally measured by lidars have been calculated for different shapes and the effective size of the crystals. These values could be used for retrieving shapes of the crystals in cirrus clouds.

The authors propose a method for the automated determination of cumulus clouds using the time series of direct and diffuse irradiance and their mean long-term values for a clear sky for at a given location.

We report on the calculation method for the development of fiber-coupled acousto-optical (AO) spectral filtration modules compatible with conventional inexpensive wide-band light sources (incandescent lamps). The formulas for main parameters of the optical systems of such modules are given. Two possible schemes (collimating and telecentric confocal) of AO filtration are discussed and compared. Their optical throughput and aberration parameters are analyzed. The proposed approach may be useful for the tunable light filtration in various applications (microscopy, endoscopy, interferometry, etc.).

Results of experiments on polarization laser sensing of high-level clouds performed at the high-altitude polarization lidar developed at National Research Tomsk State University are discussed. It is shown that orientation of crystalline ice particles in a cloud leads to different values of the measured depolarization ratio for the same cloud, which depends significantly on the azimuthal orientation of the polarization plane of sensing radiation.

The purpose of this study is the use of remote sensing data on vegetative index NDVI (Normalized Difference Vegetation Index) for predicting the spread of grassfires in the example of the Jewish Autonomous Region (JAR). Calculation of specific daily indicators of climatic-caused fire hazard is carried out according to the method of V.G. Nesterov. To calculate the spread speed of the grassfire, the MacArthur method for meadow areas was used. Pictures of the MOD09GQK product in the red and near infrared channels were used to calculate the vegetative index NDVI, which is a quantitative index of photosynthetically active biomass.

The organic films form a brightness contrast on the sea surface. It makes possible to use cheap simple and miniature systems for video monitoring of pollution of coastal marine areas by oil products in the bunkering of ships, emergency situations at oil terminals, gas and oil pipelines, hydrocarbon production platforms on the shelf, etc.^1-16 A panoramic video system with a polarization filter on the lens, located at an altitude of 90 m above sea level, can provide effective control of the water area within a radius of 7 kilometers,^17-19 and modern photogrammetry technologies allow not only to register the fact of pollution and get a portrait of the offender, but also with a high Spatial and temporal resolution to estimate the dimensions and trace the dynamics of movement and transformation of the film in a geographic coordinate system. Of particular relevance is the optical method of controlling the pollution of the sea surface at the present time with the development of unmanned aerial vehicles that are already equipped with video cameras and require only a minor upgrade of their video system to enhance the contrast of images of organic films.

In this paper we present a new measurement tool - polarimeter, based on video matrix. Polarimetric measure- ments are usefull, for example, when monitoring water areas pollutions and atmosphere constituents. New device is small enough to mount on unmanned aircraft vehicles (quadrocopters) and stationary platforms. Device and corresponding software turns it into real-time monitoring system, that helps to solve some research problems.

In this article we present the numerical study of aerosol condensation growth. Such events occurs when relative humidity exceeds 75%. We found that depolarization ratio does not uniquely determine the degree of sphericity of aerosol particles.

The work is devoted to polarization remote sensing droplet and crystal clouds by coaxial lidar. The results of numerical modeling of the distribution of the ellipticity and the semi-major axis orientation of the ellipse of polarization of lidar returns in the double-scattering approximation are discussed.

A new device for water environment transparency measuring is presented. The measurement errors connected with biofouling are estimated under experiment results. Characteristics’ accuracy and relations between TSM units are presented.

Vertical diffuse attenuation coefficient, K_d(490), is one of the key parameter required for water quality modeling, hydrodynamic and biological processes in the sea. We showed that standard level-2 product of K_d(490) was underestimated in comparison with K_d(490) values simulated by the regional model during the diatom bloom in the Black Sea. Using data of SeaWiFS, MERIS and MODIS color scanners, a regional relationship between the model value of K_d(490) and the ratio of remote sensing reflectances has been obtained. Based on the bulgarian argo-bio-buoy dataset, the relationship between the attenuation coefficient of photosynthetically active radiation and attenuation coefficient at a wavelength of 490 nm is obtained. The simplified model, below as the S-model, of the diffuse attenuation coefficient spectrum for downwelling irradiance in the Black Sea upper layer is described. As a consequence of the S-model, the link between the depth of the euphotic zone and K_d(490) has been obtained. It is shown that the K_d(490) values, retrieved from ocean color data with using the regional link and from argo-bio-buoy measurements at depths between 6-20 m, are close to each other.

From the results of monitoring measurements at the Aerosol Station of IAO SB RAS in 1997-2016, the temporal dynamics of annual average aerosol concentrations was found to vary only slightly with an insignificant negative trend. The BC concentration demonstrates a stable tendency to decrease with a trend of -2.3% a year, which for 20 years has led to a total decrease in the imaginary part of the complex refractive index of the dry basis of particles from 0.062 to 0.044. The trends of variability of the aerosol and BC content for every season copy the dynamics of annual average values. The annual behavior of the aerosol and BC concentrations is characterized by a winter maximum and a summer minimum.

An array of spectral aerosol extinction coefficients is calculated from measurements of the spectral transparency of the atmosphere on a 1 km long horizontal path in 10 regions of the wavelength range 0.5 – 4 μm. An array of angular dependences of the aerosol scattering coefficients in the angular range 1.2 – 15° is obtained by means of an aureole photometer with closed scattering volume. Measurements were carried out under conditions of smoky atmosphere. Inverse problem was solved for two empirical data arrays obtained synchronously (200 realizations) and the aerosol particle cross section size distributions were calculated. It is shown that the results of two experiments are in quite good agreement in the particle size range from 0.18 to 1.8 μm. Objective. Determination of the aerosol particle size range, in which the results of aerosol monitoring by two instrumentation complexes are most representative. Method for solving the problem. The inverse problem was solved for two empirical data arrays: a) spectral aerosol extinction coefficients β_ext(λ) in the wavelength range 0.5 – 3.9 μm; b) angular dependences of the aerosol scattering coefficients β_sct(φ) in the angular range Φ = 1.2 – 15° at the wavelength of 650 nm. The arrays β_ext(λ) and β_sct(φ) were obtained in synchronous measurements by means of two independent instrumentation complexes [1,2]. In order to obtain the aerosol particle cross-section size distribution dS/dr, the inverse problem was solved using the algorithms [3-5]. The spectral dependence of the optical constants of aerosol particles was determined from the empirical data [6, 7]. Finally, two arrays of distributions dS/dr corresponding to the initial experiments data β_ext(λ) and β_sct(φ) were calculated.

An precision of the chlorophyll-a concentration and the detrital matter absorption coefficient using different algorithms for the Black Sea are obtained on the basis of numerical experiments in which varied the depth of the optically active layers and the its albedo. The numerical experiments compared with satellite observations performed in the deepwater part of the Black Sea in the first half of summer 2000 during the intensive coccolithophorids blooms are in good agreement.

Results of reconstruction of the volume concentration and geometric cross section of the coarsely dispersed aerosol by solving the inverse problem for spectral measurements of the aerosol optical thickness (АОТ) and calculated from regression relations for the АОТ measured at wavelengths of 2.203 and 1.557 μm are compared. It is shown that the regression equations retrieved from the data collected during a one month period allow the microstructural parameters of coarsely dispersed particles to be estimated for a one year period practically without loss of accuracy.

The effect of errors related to the given optical properties inaccuracy of the atmosphere and the condition of the air-water boundary after atmospheric correction, and the error in ocean color product from the SeaWiFS and MODIS tools is considered.

The results of studies of the dynamics of forest fires in the boreal forests of Yakutia (Eastern Siberia) for 2001-2016 are presented. Variations of aerosol optical thickness (AOT), aerosol index (AI) and total carbon monoxide content during May-September were studied depending on the different forest fire activity level. It is shown that the seasonal variations of AOT, AI and CO in the most fire-dangerous years differ significantly from the fire seasons when forest fire activity was medium or low.

Stationary lidar “LOSA-S” of the center of shared facilities (CSF) “ATMOSPHERE” IAO SB RAS is intended for the study of aerosol fields in the boundary layer of the troposphere in the height range 0.5 up to 15 km, as well as for the study of crystal clouds using the polarization unit with linear and circular polarization of radiation. The scheme of simultaneous observation of the elastic and Raman scattering signals when irradiating the medium at the wavelengths of 1064, 532 and 355 nm is realized in the lidar. The lidar is based on the LOTIS-2135 Nd:YAG laser and the receiving specular telescope of the Cassegrain system with the diameter of 300 mm. In addition to the return signals of elastic scattering recorded in analog mode, the lidar records the Raman scattering signals on molecular nitrogen (387 and 607 nm) and water vapor (407 nm) in the photon counting mode. To realize the aforementioned height range, two receiving telescopes are used in the lidar for near and far zones, the signals are recorded by the same photodetectors.

An array of atmospheric aerosol optical characteristics is obtained from synchronous measurements on a long nearground path and in a local volume of air. The algorithm of statistical comparison of the data obtained is modernized. The spectral dependence of the single scattering albedo in the wavelength range 0.45 to 3.9 μm is calculated. Non-monotonic increase of albedo with wavelength is observed. Seasonal variations of albedo are estimated. Minimum values of albedo are observed in April and October, and maximum values are in July.