Software package for reconstructing reflective properties of the Earth's surface in the visible and UV ranges

A description of a software package for reconstructing the distribution of the reflection coefficient of the Earth’s surface, as well as procedures developed for a considerable reduction of the computation time, is presented. By an example of a test region in the western coast of Africa, a comparison has been performed for results obtained by the proposed algorithm, the algorithm of homogeneous correction, and the standard MOD09 NASA algorithm. The correlation coefficients of results for this test region are as follows: between the new algorithm and homogeneity correction algorithm, 0.999; between the new algorithm and the MOD09 algorithm, 0.984

Estimation of the error of the algorithm for reconstructing the reflection coefficient of the Earth surface on the example of images with the low atmospheric turbidity

An algorithm for atmospheric correction of satellite images combining the consideration of the main factors influencing imaging and a number of techniques allowing the computational time to be decreased considerably is analyzed. On the example of a series of images of the South of the Tomsk Region recorded from 7/13/2013 to 7/17/2013 with the low atmospheric turbidity, a comparison of the results of atmospheric correction using the suggested algorithm with the results obtained using the NASA MOD09 algorithm is performed. The correction error is estimated under assumption of a linear change of the reflection coefficient from image to image. Our comparison demonstrates that the results of correction differ within the correction error. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Atmospheric channel for bistatic optical communication: Simulation algorithms

Three algorithms of statistical simulation of the impulse response (IR) for the atmospheric optical communication channel are considered, including algorithms of local estimate and double local estimate and the algorithm suggested by us. On the example of a homogeneous molecular atmosphere it is demonstrated that algorithms of double local estimate and the suggested algorithm are more efficient than the algorithm of local estimate. For small optical path length, the proposed algorithm is more efficient, and for large optical path length, the algorithm of double local estimate is more efficient. Using the proposed algorithm, the communication quality is estimated for a particular case of the atmospheric channel under conditions of intermediate turbidity. The communication quality is characterized by the maximum IR, time of maximum IR, integral IR, and bandwidth of the communication channel. Calculations of these criteria demonstrated that communication is most efficient when the point of intersection of the directions toward the source and the receiver is most close to the source point. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Estimation of the influence of cloudiness on the Earth observation from space through a gap in a cloudy field

For atmospheric correction of satellite images, the problem is formulated to estimate the distance from a cloud at which its influence on the satellite image of the Earth surface can be neglected. The Monte Carlo method of conjugate trajectories is used. The gap radius in the field of continuous cloudiness at which the influence of the cloudy medium on the received signal intensity does not exceed 10 % is obtained. It is revealed that for the Lambert law of radiation reflection from the Earth surface, the curve of the dependence of the received signal intensity on the gap radius has a maximum caused by the opposite influence of light scattering by the cloudy medium and radiation reflection by the surface (adjacency effect). To further generalize the examined problem to a stochastic cloud field, the method of direct simulation of photon trajectories in a stochastic medium is compared with G. A. Titov’s method of closed equations in the gap vicinity. A comparison is carried out with the model of the stochastic medium in the form of a cloud field of constant geometric thickness consisting of rectangular clouds whose boundaries are determined by the stationary Poisson flow of points. It is demonstrated that results of calculations can differ at most by 20‒30 %; however, in some cases (for some sets of initial data), the difference for the entire region of cloud cover indices is within 7 %. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Influence of the outer scales of temperature and dynamic turbulence on the characteristics of transmitted acoustic radiation

In the present work, the problem of propagation of monochromatic acoustic radiation in the lower 500-meter layer of the plain stratified moving turbulent atmosphere is solved by the Monte Carlo method. The influence of the parameters of models of the outer scales of temperature and dynamic turbulence on the intensity of transmitted acoustic radiation intensity is investigate

Using satellite radiometric and ground based lidar measurements for detection of cirrus clouds, containing ensembles of preferred oriented ice particles

In this paper present an example of joint analysis of the data of high-level cloud sensing with a ground based polarization lidar of Tomsk State University and satellite radiometer MODIS

Conformational preference of some nonsteroidal anti-inflammatory drugs

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Experimental and theoretical investigations of the near-ground propagation of acoustic radiation in the atmosphere

Near-ground propagation of monochromatic acoustic radiation at frequencies of 300, 1000, 2000, and 3150 Hz along atmospheric paths up to 100 m long is investigated experimentally and theoretically depending on altitudes of the acoustic source and receiver. The experiment was carried out at the experimental site of the Institute of Monitoring of Climatic and Ecological Systems (IMCES) using a specially developed setup. The dependence of the recorded sound pressure level on the propagation path length and initial signal power is analyzed. The theoretical analysis is performed by the Monte Carlo method using the local estimation algorithm developed by the authors. The comparison of the experimental and theoretical results shows their satisfactory agreement, which indicates the effectiveness of the proposed algorithm and its applicability to predicting the near-ground sound propagation

Measurement of reflection coefficients of organic and non-organic media and materials in UV spectrum

Measurements of the diffuse reflection coefficients of organic and inorganic materials and media in solid, granular and liquid forms were made in the UV field of 230–400 nm. A single channel spectrometer with an integrating sphere was used. Relation between diffuse reflection coefficients and the structure and composition of the samples is discussed. These data allow us to estimate the prospect of machine vision systems application for the UV range in such areas as biology, geology, remote control of materials and media