Application of correlation lidar data to modeling and prediction of wind components.

Statistical estimation of the quality of lidar wind velocity measurements by the correlation method and the results of their application to the study of local and regional climates as well as to the reconstruction and ultrashort-range prediction (for forecasting periods

Dynamic characteristics of optical adaptive systems.

The effect of time delay on characteristics of an optical adaptive system is considered. Classification of the optical adaptive systems as dynamic feedback systems has been made. Systems with constant delay, a highspeed adaptive system as well as a new class of systems, i.e., predicting adaptive systems, are investigated.

Mean characteristics of lidar signals from broken clouds.

The problem of the backscattered laser radiation field formation is solved based on the theory of optical radiation transfer in broken cloudiness as a scattering medium with random geometry. The dependence of the energy characteristics of a lidar return averaged over the ensemble of cloud-field realizations on the type of clouds (cumulus and stratus), cloud fraction, optogeometrical parameters of a cloud field, lidar's geometric parameters, and the distance to a cloudy layer. It has been shown that over long periods the multiple light scattering between the cumulus clouds is the dominating contribution to the lidar signal power.

Dependence of the absorption coefficient of vibration-rotation transitions of dipole molecules on the resonance radiation polarization.

The dependence of the absorption coefficient for vibration-rotation transitions on ruby-laser pulse intensity and polarization has been investigated experimentally. For linearly polarized radiation, a decrease in absorption is observed as the intensity is increased. For circularly polarized radiation, no decrease is evident, even at significantly higher intensity. A qualitative interpretation of the results is presented.

Lidar differential absorption and scattering technique: theory.

The results of theoretical investigations of the differential absorption technique for sounding atmospheric water vapor are described in this paper. The sources of errors and their effect on the results of interpreting the sounding data are analyzed. The mathematical problems for inverting the lidar returns are considered.

Laser sounding of atmospheric humidity: experiment.

This paper presents the results of investigations of atmospheric humidity profiles by a lidar on the basis of a tunable ruby laser. The lidar parameters are given, and the technique of lidar measurements of water vapor content in the atmosphere using the differential absorption technique is described. The results of reconstitution of humidity profiles up to 17-km altitudes are given based on results of laser sounding.

Saturation effect for H(2)O absorption lines at ruby laser wavelengths.

The dependence of the spectral coefficient of atmospheric water vapor absorption on ruby-laser radiation intensity has been studied experimentally. Measurements were made using an optoacoustic laser spectrometer with a sensitivity of 10(-9) cm(-1) J(-1). The contours of the H(2)O absorption lines at 694.215 nm, 694.238 nm, and 694.38 nm were measured at two different values of radiation intensity within 5-100 MW/cm(2). The values of the saturation parameter were calculated using the observed decrease of absorption in the line maximum; they were 210 +/- 23 MW/cm(2), 140 +/- 15 MW/cm(2), and 180 +/- 20 MW/cm(2) for the 694.215-nm, 694.238-nm, and 694.38-nm, lines, respectively. The values of the absorption parameter are in satisfactory agreement with the calculated results. The dependence of the saturation parameter on pressures between 250-750 Torr was investigated for the isolated 694.38-nm absorption line.

Investigation of structure and dynamics of aerosol inhomogeneities in the ground layer of the atmosphere.

The development of methods for active optical sounding of the wind velocity vector on the basis of scattered signal correlation requires a detailed study of the inhomogeneity parameters of the scattering properties of the atmosphere. However, at present the information on inhomogeneity parameters is mainly limited by stating the fact of their presence and reporting on the contrast value of atmospheric scattering irregularities under definite atmospheric conditions. The knowledge of inhomogeneity sales and their lifetimes is also extremely important for correlation sounding of wind velocity. The present paper gives the results of experimental investigations of inhomogeneity parameters in the ground layer of the atmosphere.

Use of high-speed laser spectroscopy to study the absorption spectrum of atmospheric gases.

A laser spectrometer based on a tunable ruby laser has been used to determine absorption coefficients of water vapor in a multipass cell.

Propagation of laser beams in scattering media.

Experimental investigations have been undertaken of some aspects of the propagation of helium-neon gas laser radiation at lambda = 0.63 micro for different scattering media (artificial water fogs, wood smokes, model media). It has been shown that the attenuation coefficients practically coincide when coherent and incoherent radiation is scattered. The applicability limits of Bouguer-Beer's law for describing the attenuation of radiation in scattering media are investigated and the intensity of multiple forward-scattered light for different geometrical parameters of the source and radiation receiver are measured. The applicability of single scattering theory formulas for describing forward-scattered light intensity are discussed.