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70 results on '"Xin, Wenhui"'

6. The algorithm of microphysical-parameter profiles of aerosol and small cloud droplets based on the dual-wavelength lidar data.

Author

Di, Huige, Wang, Xinhong, Chen, Ning, Guo, Jing, Xin, Wenhui, Li, Shichun, Guo, Yan, Yan, Qing, Wang, Yufeng, and Hua, Dengxin

Subjects
CLOUD droplets, ATMOSPHERIC aerosols, AEROSOLS, LIDAR, GAMMA distributions, TEMPERATURE inversions, STRATOCUMULUS clouds, TROPOSPHERIC aerosols
Abstract

This study proposed an inversion method for atmospheric-aerosol or cloud microphysical parameters based on dual-wavelength lidar data. The matching characteristics between aerosol and cloud particle size distributions and gamma distributions were studied using aircraft observation data. The feasibility of the retrieval of the particle effective radius from lidar ratios and backscatter ratios was simulated and studied. A method for inverting the effective radius and number concentration of atmospheric aerosols or small cloud droplets using the backscatter ratio was proposed, and the error sources and applicability of the algorithm were analyzed. This algorithm was suitable for the inversion of uniformly mixed and single-property aerosol layers or small cloud droplets. Compared with the previous study, this algorithm could quickly obtain the microphysical parameters of atmospheric particles and has good robustness. For aerosol particles, the inversion range that this algorithm can achieve is 0.3–1.7 µm. For cloud droplets, it is 1.0–10 µm. An atmospheric-observation experiment was conducted using the multi-wavelength lidar developed by Xi'an University of Technology, and a thin cloud layer was captured. The microphysical parameters of aerosol and clouds during this process were retrieved. The results clearly demonstrate the growth of the effective radius and number concentration. [ABSTRACT FROM AUTHOR]

Published
2024
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12. 基于气溶胶光学参数的拉曼激光雷达重叠因子校正方法

Author

Wang Xinhong, 王欣红, primary, Di Huige, 狄慧鸽, additional, Wang Yaya, 王娅娅, additional, Yin Zhenzhen, 尹珍珍, additional, Yuan Yun, 袁云, additional, Yang Tao, 杨涛, additional, Yan Qing, 闫庆, additional, Li Shichun, 李仕春, additional, Xin Wenhui, 辛文辉, additional, and Hua Dengxin, 华灯鑫, additional

Published
2023
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18. Retrieval of aerosol microphysical parameters based on a few optical parameters from lidar.

Author

Li, Siwen, Di, Huige, Zhang, Xingqi, Xin, Wenhui, Zeng, Nan, Ma, Hui, Li, Yan, and Hua, Dengxin

Subjects
AEROSOLS, PARTICLE size distribution, PRINCIPAL components analysis, LIDAR, TROPOSPHERIC aerosols
Abstract

Aerosol optical parameters detected by multiwavelength lidar can be used for the retrieval of the aerosol particle size distribution and aerosol microphysical properties (AMP). Based on the retrieval for AMPs using standard principal component analysis (PCA) algorithm, the influence of the number of optical parameters on the PCA retrieval results is studied. Four optical parameters (3β + α) or three optical parameters (3β) are selected for retrieval instead of five optical parameters (3β + 2α), respectively. The results show that three optical parameters and four optical parameters can be used for the retrieval of AMPs. For 3β + α, the accuracy of effective radius and volume concentration (VC) are 37% and 56%, respectively. For 3β, the accuracy of effective radius and VC are 37% and 74% respectively. The sensitivity analysis of the PCA algorithm with less than five optical parameters is also discussed, and this method is applied to the retrieval of cloud base particle size distribution. [ABSTRACT FROM AUTHOR]

Published
2023
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27. 甲醛气体探测的DIAL波长选择及探测性能

Author

辛文辉 Xin Wenhui, 毕元硕 Bi Yuanshuo, 李仕春 Li Shichun, 李耀飞 Li Yaofei, and 华灯鑫 Hua Dengxin

Subjects
Space and Planetary Science, Aerospace Engineering, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics
Published
2022
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31. Continuous tunable cavity Fabry–Perot interferometer by using potassium dideuterium phosphate with two ring electrodes

Author

Dengxin Hua, Jingjing Liu, Ning Chen, He Tingyao, Li Wang, Meng Yuan, Qing Yan, Xin Wenhui, Jun Wang, and Tiantian He

Subjects
Materials science, business.industry, Aperture, Physics::Optics, Holographic interferometry, 01 natural sciences, Atomic and Molecular Physics, and Optics, Potassium dideuterium phosphate, 010309 optics, symbols.namesake, Interferometry, chemistry.chemical_compound, Optics, chemistry, 0103 physical sciences, symbols, Electrical and Electronic Engineering, Rayleigh scattering, business, Engineering (miscellaneous), Refractive index, Free spectral range, Fabry–Pérot interferometer
Abstract

In order to perform hyperspectral remote sensing, we present a continuous tunable cavity Fabry-Perot interferometer (FPI) by using potassium dideuterium phosphate (DKDP) with two ring electrodes. DKDP has the good performances of high transmittance in the ultraviolet band and large aperture of 20 mm (the maximum aperture can be 100 mm). Since the resonant frequency of an FPI can be continuously varied with the refractive index change of DKDP caused by the electro-optic effect, the influence of moving parts on resonant frequency can be eliminated. Digital holographic interferometry based on a Mach-Zehnder interferometer is employed to measure the refractive index modulation of DKDP. The parameters of FPI are characterized by using an experimental setup with frequency locking and temperature control technologies. Taking the temperature-measuring high-spectral-resolution lidar based on Rayleigh-Brillouin scattering as an example, a continuous tunable cavity FPI with the full width at half-maximum of 200 MHz and free spectral range of 11.12 GHz is realized. The results are in good agreement with the designed parameters.

Published
2019
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38. Design and analysis of high-spectral resolution lidar discriminator

Author

Xin Wenhui, Zhang Jia-Qi, Wang Li, Di Huige, Gao Fei, Zhang Zhan-Fei, Hua Dengxin, Hua Hang-Bo, and Zhao Heng

Subjects
Materials science, business.industry, Scattering, Mie scattering, General Physics and Astronomy, Interferometry, symbols.namesake, Optics, Transmittance, symbols, Spectral resolution, Rayleigh scattering, business, Fabry–Pérot interferometer, Beam divergence
Abstract

An accurate aerosol optical property can be obtained by a high spectral resolution lidar (HSRL) technique, which employs a narrow spectral filter to suppress Mie scattering in the lidar return signal. The ability for filter to suppress Rayleigh scattering is critical for the HSRL. In the HSRL system, Rayleigh scattering signal is obtained and aerosol scattering is suppressed at least by a factor of 10-5 through using the narrow filter. Usually, an atomic absorption filter can reach this level. While, the gaseous absorption lines do not exist at many convenient laser wavelengths, thus restricting the development of multi-wavelength HSRL instrument. A new and practical filtering method is proposed to realize the precise detection of atmospheric optical parameters by using the reflection field of Fabry-Perot (FP) interferometer. An optical splitting system with high spectral resolution is designed and its spectral characteristics are analyzed. Based on the characteristic of hyper-spectral lidar detection signal, the variations of spectral separation ratio and Rayleigh signal transmittance with reflectivity and cavity length are discussed. Spectral separation ratio is the transmittance ratio of aerosol scattering signal to molecular scattering signal through the spectral filter. With the increases of FP cavity length and surface reflectivity, the spectral separation ratio decreases and the Rayleigh signal transmission increases. The high spectral separation ratio and Rayleigh signal transmittance can be achieved by the reflection field of FP interferometer when the FP cavity length and reflectivity parameter can be chosen reasonably. We design an FP interferometer with a cavity length of 36 mm and reflectivity of 0.4. Its spectral separation ratio is affected by the echo divergence and incidence angle. The spectral separation ratio keeps unchanged when the beam divergence angle is within 3 mrad and the incident angle of the beam is within 0.5 mrad. In addition, a simulation analysis model is established based on the error propagation. An observed actual Mie-scattering profile is used for analyzing the errors. Moreover, the influences of the divergence angle and the incident angle of the echo beam on detection results are also discussed. The results show that the proposed FP interferometer can achieve fine spectral separation of Mie and Rayleigh scattering signal, and the error of detection result is not sensitive to laser divergence angle. Fine aerosol optical parameters can be achieved when the divergence and incidence angles are controlled within 10 mrad and 1.5 mrad, respectively.

Published
2017
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42. Design of Auto Collimation System for Coaxial Mie Lidar

Author

宋跃辉 Song Yue-hui, 闫庆 Yan Qing, 李仕春 Li Shichun, 辛文辉 Xin Wenhui, 鲁雷雷 Lu Leilei, and 华灯鑫 Hua Dengxin

Subjects
business.industry, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Atomic and Molecular Physics, and Optics, Collimated light, Electronic, Optical and Magnetic Materials, 010309 optics, Lidar, Optics, 0103 physical sciences, Electrical and Electronic Engineering, Coaxial, 0210 nano-technology, business, Geology, Remote sensing
Published
2016
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