International Workshop on Lidar Multiple Scattering Experiments最新文献_第2页

Diffusion patterns of a pulsed laser beam seen by a monostatic and a bistatic CCD lidar 单站和双站CCD激光雷达观察到的脉冲激光束的扩散模式

International Workshop on Lidar Multiple Scattering Experiments Pub Date : 2005-03-17 DOI: 10.1117/12.617460

U. Oppel

{"title":"Diffusion patterns of a pulsed laser beam seen by a monostatic and a bistatic CCD lidar","authors":"U. Oppel","doi":"10.1117/12.617460","DOIUrl":"https://doi.org/10.1117/12.617460","url":null,"abstract":"The transport of light through the atmosphere is modeled as a Levy-type Markovian jump process of stochastic corpuscular multiple scattering of photons including polarization. The backward Kolmogorov differential equation of this Markovian jump process is the general radiative transfer equation with polarization. Based on this stochastic multiple scattering process, Monte Carlo codes have been designed to calculate lidar returns containing essential contributions of multiple scattering (dense clouds, space). Since the retrieval of micro-physical cloud parameters is an ill-posed problem, it is necessary to collect as much additional information about the cloud as possible. Such information can be obtained by using multiple field of view lidars or CCD lidars. Based on the stochastic multiple scattering process, a new Monte Carlo code has been designed allowing for the calculation of the off-axis diffusion patterns of the emitted pulsed laser beam as it is \"seen from the monostatic or bistatic CCD receiver.\" These patterns allow for the classification of different types of scattering particles. Some examples of such patterns will be shown for clouds of radiative fog and of collections of randomly oriented oblate and prolate cylinders and spheroids. These patterns allow for a simple classification of clouds.","PeriodicalId":359097,"journal":{"name":"International Workshop on Lidar Multiple Scattering Experiments","volume":"180 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133401732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

About computation of multiple scattering of inclined beam by spatial-frequency characteristics method 用空间频率特性法计算倾斜波束的多次散射

International Workshop on Lidar Multiple Scattering Experiments Pub Date : 2005-03-17 DOI: 10.1117/12.617416

Tamara A. Sushkevich, S. Strelkov, E. V. Vladimirova, A. K. Kulikov, Svetlana V. Maksakova

引用次数: 0

Peaked phase function approximation in the solution of radiative transfer equation 辐射传递方程的峰值相函数近似解

International Workshop on Lidar Multiple Scattering Experiments Pub Date : 2005-03-17 DOI: 10.1117/12.617475

V. Kisselev

{"title":"Peaked phase function approximation in the solution of radiative transfer equation","authors":"V. Kisselev","doi":"10.1117/12.617475","DOIUrl":"https://doi.org/10.1117/12.617475","url":null,"abstract":"Highly peaked phase functions in the integral term of radiative transfer equation (RTE) create difficulties for its numerical solution. After Fourier expansion of this equation the necessity to use high-degree polynomials for the approximation of dependence of harmonics on polar angle arises. High-degree polynomials require in turn high number of grid points for discretisation of the integral term, as with a sparse grid traditionally applied Gaussian numerical scheme does not provide for flux conservation. Processor time consumption increase drastically with the increase of the number of grid points and and for multiple solution of RTE (e.g. for the solution of inverse problem by iterations) traditional approaches can hardly be applied. Development of flux conserving numerical scheme allowing for the arbitrary number of grid points is possible on the basis of finite element method. This method significantly increases the accuracy of calculation of harmonics of intensity in the case of peaked phase function, but the number of harmonics providing for necessary accuracy of total intensity remains high enough. The main reason here is the presence of the peak in the dependence of intensity on azimuth. With certain assumptions it becomes possible to obtain approximate analytical solution for highly peaked phase functions which takes into account multiple scattering and gives rather accurate results in a comparatively wide region near the intensity peak. On the basis of this solution the computational scheme is developed, presenting the final RTE solution as the sum of the above approximate solution and a smooth function, which is obtained by numerically solving the transformed RTE. For this smooth solution of RTE much less harmonics have to be obtained and computer time consumption is significantly reduced.","PeriodicalId":359097,"journal":{"name":"International Workshop on Lidar Multiple Scattering Experiments","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129168023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Extinction-to-backscatter ratio calculated for ice crystal particles 计算冰晶粒子的消光-后向散射比

International Workshop on Lidar Multiple Scattering Experiments Pub Date : 2005-03-17 DOI: 10.1117/12.617408

N. Kustova, A. Borovoi, U. Oppel

引用次数: 0

Scattering matrices for ice crystal particles with preferred orientations 具有优选取向的冰晶颗粒散射矩阵

International Workshop on Lidar Multiple Scattering Experiments Pub Date : 2005-03-17 DOI: 10.1117/12.617419

A. Burnashov, A. Borovoi, A. Cohen, U. Oppel

引用次数: 0

Monte Carlo simulation of radiation transfer in optically anisotropic clouds 光学各向异性云中辐射传输的蒙特卡罗模拟

International Workshop on Lidar Multiple Scattering Experiments Pub Date : 2005-03-17 DOI: 10.1117/12.617203

S. Prigarin, A. Borovoi, P. Bruscaglioni, A. Cohen, I. Grishin, U. Oppel, T. Zhuravleva

引用次数: 5

Phase matrix of ice crystals in noctilucent clouds 夜光云中冰晶的相位矩阵

International Workshop on Lidar Multiple Scattering Experiments Pub Date : 2005-03-17 DOI: 10.1117/12.617435

A. Kokhanovsky

引用次数: 3

Statistical simulation of laser radiation transfer in stochastic scattering media 随机散射介质中激光辐射传递的统计模拟

International Workshop on Lidar Multiple Scattering Experiments Pub Date : 2005-03-17 DOI: 10.1117/12.617497

B. A. Kargin

引用次数: 0

Development of an optical model for cirrus clouds 卷云光学模式的发展

International Workshop on Lidar Multiple Scattering Experiments Pub Date : 2005-03-17 DOI: 10.1117/12.617402

A. Borovoi, A. Cohen, N. V. Kustova, U. Oppel

引用次数: 0

Light scattering by nonspherical particles: some practical aspects 非球形粒子的光散射:一些实际问题

International Workshop on Lidar Multiple Scattering Experiments Pub Date : 2005-03-17 DOI: 10.1117/12.617313

V. Farafonov, V. Il’in, N. Voshchinnikov, M. S. Prokopjeva

引用次数: 1