Optical Communication on Scattered or Reflected Laser Radiation

2019 ◽  
pp. 15-24
Author(s):  
Vladimir Belov
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Communication Systems ◽  
Radiation Transfer ◽  
Communication Channels ◽  
Theoretical Research ◽  
Visible Range ◽  
Open Communication ◽  
The Monte Carlo Method ◽  
Communication Errors

Results of theoretical and experimental research of NLOS (NonLine of Sight) communication systems in the atmosphere, under water, and in mixed media based on publications of authors from China, Canada, Greece, the USA, Great Britain, Russia, and other countries are discussed in the present work. The theory of radiation transfer and the linear systems theory provide the basis for theoretical research. The radiation transfer equation is solved by the Monte–Carlo method in the singlescattering approximation. It is demonstrated that approximate methods are applicable when the average scattering multiplicity in open communication channels does not exceed 1. The Monte Carlo method is used to study the influence of opticalgeometric parameters of schemes of communication channels on the probabilities of communication errors, signal/noise ratios, limiting base lengths, attenuation of informationcarrying signals, and their superposition leading to communication errors. Examples of communications in the atmosphere in the UV range at distances up to 1300 m, in the visible range up to70 km, and under water up to 20 m are given. Search for optimal methods of signal modulation, development of software and hardware complexes for numerical simulation of the transfer properties of communication channels, refinement of analytical models of impulse transfer characteristics of noncoplanar schemes of bistatic optoelectronic communication systems (OECS), and research of the effect of winddriven sea waves and processes of radiation scattering in water are planned to study the efficiency of operation of the communication systems and to expand ranges of variations of the input NLOS and OECS parameters in the experiments carried out in natural water reservoirs.

scholarly journals Analysis of the Balmer discontinuity behavior of Be stars by the Monte Carlo method

2010 ◽  
Vol 6 (S272) ◽  
pp. 386-387
Author(s):  
Alicia Cruzado
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Wavelength Range ◽  
Radiation Transfer ◽  
Circumstellar Envelope ◽  
Spherically Symmetric ◽  
Be Stars ◽  
Temperature Distributions ◽  
The Monte Carlo Method ◽  
Photospheric Model

AbstractFor a given photospheric model, we study the behavior of the BD as different density and temperature distributions in the circumstellar envelope are assumed. For non spherically symmetric envelopes, we analyze the variation of the BD when the angle of observation varies. The radiation transfer through the medium is handled by means of the Monte Carlo method. We calculate the flux emitted by the star+envelope system in a small wavelength range around the BD. The calculations are made under LTE conditions.

The Past and Future of the Monte Carlo Method in Thermal Radiation Transfer

2021 ◽  
Author(s):  
John R. Howell ◽  
Kyle Daun
Keyword(s):  
Monte Carlo ◽  
Energy Transfer ◽  
Monte Carlo Method ◽  
Radiation Transfer ◽  
Massively Parallel ◽  
Radiative Energy ◽  
Quantum Computers ◽  
The Past ◽  
Radiative Energy Transfer ◽  
The Monte Carlo Method

Abstract The history and progress in Monte Carlo methods applied to radiative energy transfer are reviewed, with emphasis on advances over the past 25 years. Unresolved issues are outlined, and comments are included about the outlook for the method as impacted by the advances in massively parallel and quantum computers.

Simulation of the Scattering Process Effect on High-Temperature Jet Radiation Intensity by the Monte Carlo Method

2020 ◽  
pp. 28-43
Author(s):  
I.S. Grigorev
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Radiation Intensity ◽  
Radiation Transfer ◽  
Computational Algorithm ◽  
Radiation Energy ◽  
Scattering Medium ◽  
The Monte Carlo Method ◽  
Direct Numerical Solution ◽  
Research Show

The purpose of the paper was to study the scattering effect in the gas jet model on the angular dependence of the radiation intensity. Along with the Monte Carlo method used as the main calculation method, we applied a direct numerical solution of the equation of radiation transfer in a non-scattering medium, known as the discrete directions method, or Ray-Tracing Method. We compared the results obtained using the two methods when calculating a non-scattering medium in order to verify the solution according to the Monte Carlo scheme. Furthermore, we calculated the medium with an increasing value of the local scattering coefficient. Findings of research show the significant effect of scattering processes on the redistribution of radiation energy from the surface of the object. The computational algorithm is implemented on the CUDA C architecture. The use of analytical jet models, e.g. according to Abramovich's theory, and the results of calculations in the computational gas dynamics packages makes it possible to calculate the values of the radiation intensity for a wide class of objects

scholarly journals Providing the environmental safety by increasing the efficiency of firefighting in unsheltered timber warehouses

2021 ◽  
pp. 123-129
Author(s):  
E. M. Hulida ◽  
I. V. Pasnak ◽  
O. E. Vasylieva ◽  
I. O. Movchan
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Mathematical Models ◽  
Combustion Products ◽  
Environmental Safety ◽  
Theoretical Research ◽  
The Monte Carlo Method ◽  
Fire Front ◽  
Free Development ◽  
The Impact

Purpose. To develop a method for reducing the impact of fires in unsheltered timber warehouses on the environmental safety by reducing the duration of free burning of timber, the speed of fire front spread, emissions of combustion products and the duration of the firefighting. Methodology. During the experimental research, the method of fractional factor experiment was used. Theoretical research was performed using optimization mathematical models. The Monte Carlo method is used to solve optimization problems. To implement this method, block diagrams of algorithms was developed, based on written corresponded computer programs. Findings. The method was developed for reducing the impact of fires in unsheltered timber warehouses on the environmental safety by reducing the duration of free development of the fire, the speed of fire front spread, the concentration of combustion products and the duration of the fire. Fire prevention measures to reduce the duration of fire and to reduce emissions of combustion products due to fires in unsheltered timber warehouses was implemented by using an automated system to determine the fire extinguishing means and forces by setting an optimization problem, applying the Monte Carlo method and developing software to solve it. Originality. The scientific novelty is the justification of ways to reduce the duration of the free development of fire and to reduce the amount of toxic emissions using optimization mathematical models. Practical value. It is possible to use the obtained results in the practical activities of fire and rescue units of the SES of Ukraine and provide environmental safety in case of fire in unsheltered timber warehouse due to the practical implementation of administrative, legal and economic methods.

scholarly journals A Method for Estimating the Cloud Adjacency Effect on the Ground Surface Reflectance Reconstruction from Passive Satellite Observations through Gaps in Cloud Fields

Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1512
Author(s):  
Mikhail V. Tarasenkov ◽  
Matvei N. Zonov ◽  
Marina V. Engel ◽  
Vladimir V. Belov
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Radiation Transfer ◽  
Ground Surface ◽  
Interpolation Formula ◽  
Statistical Simulation ◽  
Satellite Observations ◽  
Surface Reflectance ◽  
Surface Areas ◽  
The Monte Carlo Method

A method for estimating the cloud adjacency effect on the reflectance of ground surface areas reconstructed from passive satellite observations through gaps in cloud fields is proposed. The method allows one to estimate gaps of cloud fields in which the cloud adjacency effect can be considered small (the increment of the reflectance Δrsurf≤ 0.005). The algorithm is based on statistical simulation by the Monte Carlo method of radiation transfer in stochastic broken cloudiness with a deterministic cylindrical gap. An interpolation formula is obtained for the radius of the cloud adjacency effect that can be used for the reconstruction the ground surface reflectance in real time without calculations by the Monte Carlo method.

UGR CALCULATION BASED ON THE LUMINANCE SPATIAL-ANGULAR DISTRIBUTION

2020 ◽  
Vol 2020 (4) ◽  
pp. 25-32
Author(s):  
Viktor Zheltov ◽  
Viktor Chembaev
Keyword(s):  
Monte Carlo ◽  
Angular Distribution ◽  
Monte Carlo Method ◽  
Visual Task ◽  
New Method ◽  
Lighting System ◽  
Preliminary Assessment ◽  
System A ◽  
The Monte Carlo Method

The article has considered the calculation of the unified glare rating (UGR) based on the luminance spatial-angular distribution (LSAD). The method of local estimations of the Monte Carlo method is proposed as a method for modeling LSAD. On the basis of LSAD, it becomes possible to evaluate the quality of lighting by many criteria, including the generally accepted UGR. UGR allows preliminary assessment of the level of comfort for performing a visual task in a lighting system. A new method of "pixel-by-pixel" calculation of UGR based on LSAD is proposed.

PSHA software review based on the Monte Carlo method

2020 ◽  
pp. 14-24
Author(s):  
V.A. Mironov ◽  
S.A. Peretokin ◽  
K.V. Simonov
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Seismic Hazard ◽  
Hazard Analysis ◽  
Software Review ◽  
Seismic Hazard Analysis ◽  
Probabilistic Seismic Hazard ◽  
Test Calculation ◽  
Seismic Surveys ◽  
The Monte Carlo Method

The article is a continuation of the software research to perform probabilistic seismic hazard analysis (PSHA) as one of the main stages in engineering seismic surveys. The article provides an overview of modern software for PSHA based on the Monte Carlo method, describes in detail the work of foreign programs OpenQuake Engine and EqHaz. A test calculation of seismic hazard was carried out to compare the functionality of domestic and foreign software.

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