Journals >Journal of Atmospheric and Environmental Optics
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2011
Volume: 6 Issue 2
13 Article(s)
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Research Article
[in Chinese]
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 1 (2011)
Statistical Characteristics of Vertical Distribution of Atmospheric Structure Constant of Refractive Index C2n
Gang SUN, Ning-quan WENG, and Li-ming XIAO
The atmospheric structure constant of refractive index C2n is an important parameter of denoting atmospheric turbulence. The C2n is measured both in noonday and at night in everyday at all seasons in Hefei, respectively, using QHTP-2 micro-thermal meter. The vertical profile of C2n in Hefei(0～25 km)is investigated by aThe atmospheric structure constant of refractive index C2n is an important parameter of denoting atmospheric turbulence. The C2n is measured both in noonday and at night in everyday at all seasons in Hefei, respectively, using QHTP-2 micro-thermal meter. The vertical profile of C2n in Hefei(0～25 km)is investigated by analysis of experimental data, and the statistical matrix and statistics distribution is discussed in detail. It’s shown that variance profile of C2n in Hefei coincide with lognormal distribution, the probability distribution of C2n has conspicuous difference day and night..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 83 (2011)
Measurement of Turbulence Information Using Mie Scattering Lidar
Chao-long CUI, Hong-hua HUANG, Hai-ping MEI, Zhi-bo NI, Shao-lin WANG, Kai-fa CAO, Xin FANG, and Rui-zhong RAO
A theory of measuring turbulence information using Mie scattering lidar is introduced. The feasibility of measuring turbulence with existing AML-2 Mie scattering lidar is analyzed and some experiments are performed in the horizontal direction on March 15, 2009. The echo signal curve and results of data analysis show thA theory of measuring turbulence information using Mie scattering lidar is introduced. The feasibility of measuring turbulence with existing AML-2 Mie scattering lidar is analyzed and some experiments are performed in the horizontal direction on March 15, 2009. The echo signal curve and results of data analysis show that, the effective range of measuring turbulence with AML-2 Mie scattering lidar is about 300～820 m. The value of normalized variance of the irradiance fluctuations, called scintillation index, is between 0.001 and 0.1. It increases with the increment of propagation distance, and the phenomenon of scintillation saturation is not obvious. The value of atmospheric refractive index structure constant is about 1.0×10-15m-2/3, and basically maintains homogenous in the horizontal direction. On the whole, the tendencies of scintillation index and refractive index structure constant with propagation distance are almost similar to the theoretical results..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 89 (2011)
Atmospheric Water Vapor Concentration Measurement Method Based on Tunable Diode Laser Absorption Spectroscopy
Zhen-yu XU, Wen-qing LIU, Rui-feng KAN, Yu-jun ZHANG, Shuai ZHANG, Xiao-wen SHU, Ying HE, Liang ZHANG, and Yuan-yuan TANG
A water vapor concentration measurement method was studied based on direct absorption spectroscopy techniques. Using DFB diode laser as light source, the concentration of water vapor is obtained through the integrated absorbance inversion. First a low-order polynomial baseline fitting was carried out on sub-regions of A water vapor concentration measurement method was studied based on direct absorption spectroscopy techniques. Using DFB diode laser as light source, the concentration of water vapor is obtained through the integrated absorbance inversion. First a low-order polynomial baseline fitting was carried out on sub-regions of the transmitted signal to eliminate the effect of diode-laser output power fluctuation and the absorbance curve was obtained. Then integrated absorbance can be inverted through line-shape fitting using Levenberg-Marquardt non-linear least-squares fitting method. Two absorption lines for concentration measurement near 1.4 μm of water vapor were selected to verify the method..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 95 (2011)
Measurement of Water Turbidity Combined with Scattering and Transmission Method
Kai ZHANG, Yu-jun ZHANG, Gao-fang YIN, Zhi-gang WANG, Xue XIAO, Huan-bo WANG, Li-quan GUO, Jing-bo DUAN, and Wen-qing LIU
Two kinds of common measuring methods of water turbidity, scattering method and transmission method are introduced from principles, characteristics and application situations. Then a synthesis detection method-ratio method, suitable for measurement of water turbidity changing in a large range is put forward based on chTwo kinds of common measuring methods of water turbidity, scattering method and transmission method are introduced from principles, characteristics and application situations. Then a synthesis detection method-ratio method, suitable for measurement of water turbidity changing in a large range is put forward based on characteristics of scattering and transmission method. Tenging TTS turbidimeter on the basis of ratio method and self-made experiment platform are used to measure the turbidity of Formazine standard solution of different turbidity values. The measured data of Tenging TTS turbidimeter and the self-made experiment platform are listed, the data-processing formulas are deduced and the turbidity values with different methods are calculated. Results indicate that with the ratio method, the measurement accuracy of water turbidity can be improved effectively and measurement range is also extended..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 100 (2011)
Urban Road Detection of High Resolution Remote Sensing Images Based on Snakes Model
Hai-liang SHI, Shao-guang ZHOU, and Yong XU
Based on the active contour model (Snakes) theory, the road extraction of high resolution remote sensing images is studied. According to characteristics of roads in high resolution remote sensing images, an active contour model more suited to the road extraction is drawed by improving the existing method, and the road Based on the active contour model (Snakes) theory, the road extraction of high resolution remote sensing images is studied. According to characteristics of roads in high resolution remote sensing images, an active contour model more suited to the road extraction is drawed by improving the existing method, and the road extraction is completed. IKONOS image of 1 m resolution is studied, and results show that this method can be used to extract the road edge information of high resolution images..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 106 (2011)
Direct Inversion Method of Shallow-Water Bathymetry from Hyperion Data
Yan ZHOU, and Zhi-shen LIU
Using EO-1 Hyperion hyperspectral remote sensing data, the shallow-water bathymetry inversing in Hainan Island is studied. The key techniques in inversing the bathymetry are retrieve of sea water diffuse attenuation coefficient and classification of seabed. Principal component analysis method is used for seabed classifUsing EO-1 Hyperion hyperspectral remote sensing data, the shallow-water bathymetry inversing in Hainan Island is studied. The key techniques in inversing the bathymetry are retrieve of sea water diffuse attenuation coefficient and classification of seabed. Principal component analysis method is used for seabed classification. The diffuse attenuation coefficient Kd is derived by using QAA algorithm which performs well in optical deep water. Kd obtained from QAA needs to be corrected in some coastal areas with optical shallow water and calculated by direct inversion based on radioactive transfer theory to obtain the bathymetry. It is concluded that the water depth derived from direct inversion can match with the marine map..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 112 (2011)
High-Speed Realization of Centroid Tracking Algorithm Used in DSP with Small Internal RAM
Lai-an QIN, Zai-hong HOU, Xu JING, and Shou-chuan ZHANG
A high-speed beacon detecting and processing system taking TMS320DM6437 as internal RAM is designed. The internal RAM of TMS320DM6437 is so small that the centroid tracking algorithm can’t run quickly. To solve the problem, a new image processing strategy based on centroid tracking algorithm is put forward, which can kA high-speed beacon detecting and processing system taking TMS320DM6437 as internal RAM is designed. The internal RAM of TMS320DM6437 is so small that the centroid tracking algorithm can’t run quickly. To solve the problem, a new image processing strategy based on centroid tracking algorithm is put forward, which can keep the original tracing precision and reliability of centroid tracking algorithm and can be used for a DSP system with small internal RAM..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 118 (2011)
Technology of Precise Measurement of Slit Aperture Area
Bo HE, Xiao-bing ZHENG, Xin LI, Kai LI, and Wen-bin XU
In order to achieve the absolute uncertainty which is less than 0.05% and the relative stability which is 0.03% per year in 0.4～1.0 μm of solar absolute spectral irradiance observation, the slit aperture area must be measured with high-precision in the development of solar absolute irradiance spectra-radiometer. The flIn order to achieve the absolute uncertainty which is less than 0.05% and the relative stability which is 0.03% per year in 0.4～1.0 μm of solar absolute spectral irradiance observation, the slit aperture area must be measured with high-precision in the development of solar absolute irradiance spectra-radiometer. The flux comparison method is developed by using laser scanning for precise measurement of the slit aperture area. The laser-illuminated integrating sphere system is used as a light source, and the high-precision trap detector is used to receive signals. Small size apertures can be measured without a reference aperture. In the measurement of the entrance area of solar absolute irradiance spectra-radiometer of which the nominal area is 7 mm×0.1 mm, the total relative uncertainty is about 4.5×10－4..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 122 (2011)
Climatological Characteristics of VIRS Channels for Precipitating Cloud in Summer over the Tropics and Subtropics
Yun-fei FU, Peng LIU, Qi LIU, Ming MA, Liang SUN, and Yu WANG
Climatological characteristics of visible and infrared scanner(VIRS), mainly at channel 0.63 μm and 10.8 μm, from precipitating clouds including stratiform and convective precipitation in summer from 1998 to 2007 over the tropics and subtropics are investigated based on combining measurements of VIRS and tropical rainfClimatological characteristics of visible and infrared scanner(VIRS), mainly at channel 0.63 μm and 10.8 μm, from precipitating clouds including stratiform and convective precipitation in summer from 1998 to 2007 over the tropics and subtropics are investigated based on combining measurements of VIRS and tropical rainfall measuring mission (TRMM) precipitation radar(PR) together with the precipitating cloud identification of PR detections. Results indicate the distributions of more than 0.5 mean reflectivity at channel 0.63 μm for precipitating clouds located in the intertropical convergence zone (ITCZ), southern Pacific convergence zone (SPCZ), Asian monsoon region, tropical Africa, North America and southern tropical America. The maximum mean reflectivity over these regions is over 0.7. Generally, the mean reflectivity of precipitating clouds over land is larger than that over ocean. On the contrary, the mean reflectivity for non-precipitating circumstance over the tropics and subtropics only varies from 0.1 to 0.4. For 95% convective precipitation, its mean reflectivity is over 0.5 against only 50% stratiform precipitation with such mean reflectivity. At channel 10.8 μm, the mean radiant temperature lower than 250 K appears in the precipitation regions over Asian monsoon, ITCZ, SPCZ and tropical Africa accompanying with higher than 280 K in non-precipitation regions. The mean radiant temperature of most convective precipitation at channel 10.8 μm is lower than 230 K over the tropical Africa, Tibet plateau, the central America and eastern tropical Pacific Ocean while that of most stratiform precipitation varies from 280 to 290 K over the northeast and southeast Pacific, North Africa, South Africa and most parts of South America. Moreover, the radiant temperature of precipitation cloud over the eastern hemisphere is 10 K higher than that over the western hemisphere coincidently with the higher reflectivity at channel 0.63 μm in the eastern hemisphere..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 129 (2011)
Analysis of Vertical Distribution of Atmospheric Ozone over Hefei
Shun-xing Hu, Xiang-qian Meng, Kai-fa Cao, Zhi-hai Xu, Huan-ling Hu, and Ying-jian Wang
L625 DIAL system was developed in Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences in 1993. This system has been used to monitor roundly atmospheric ozone profiles at Hefei since 1996. Ozone data measured by L625 DIAL from 1996 to 2009 were analyzed, and comparisons of data were taken between LL625 DIAL system was developed in Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences in 1993. This system has been used to monitor roundly atmospheric ozone profiles at Hefei since 1996. Ozone data measured by L625 DIAL from 1996 to 2009 were analyzed, and comparisons of data were taken between L625 DIAL and AURA satellite. Monthly and season average ozone profiles over Hefei were presented. Ozone change trend was also analyzed..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 141 (2011)
Vertical Profiles of Boundary Layer Pollutants Measured by AML-2 Mobile Lidar at Hefei
Kai-fa CAO, and Shun-xing HU
Schematic and system parameters of AML-2 mobile lidar for monitoring atmospheric pollutants are presented. Fundamental principles of lidar and its data processing methods are detailedly analyzed. The vertical profiles of SO2 , NO2 , O3 and aerosol over Hefei are presented. The vertical density of SO2 and NO2 are somewhSchematic and system parameters of AML-2 mobile lidar for monitoring atmospheric pollutants are presented. Fundamental principles of lidar and its data processing methods are detailedly analyzed. The vertical profiles of SO2 , NO2 , O3 and aerosol over Hefei are presented. The vertical density of SO2 and NO2 are somewhat lower, but the vertical density of ozone has obvious time evolution and is relevant to the solar radiation. The height of boundary layer top has obvious diurnal variation. The characteristics of pollutants profiles are discussed with some meteorological parameters..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 146 (2011)
Characteristics of Aerosol Size Distribution in Hefei, Yuexi, Xiamen and Beijing
Xue-bin LI, Shun-xing HU, Wen-yue ZHU, Yin-bo HUANG, Qing-shan XU, He-li WEI, Ying-jian WANG, and Huan-ling HU
The atmospheric aerosol is measured with optical particle counter at Hefei, Yuexi, Xiamen and Beijing from November 1998 to June 2010 in order to study the aerosol size distribution in typical areas of eastern China, and to establish the aerosol size distribution model. The lognormal distribution is used to fit the sizThe atmospheric aerosol is measured with optical particle counter at Hefei, Yuexi, Xiamen and Beijing from November 1998 to June 2010 in order to study the aerosol size distribution in typical areas of eastern China, and to establish the aerosol size distribution model. The lognormal distribution is used to fit the size distribution to analyze and compare the size distribution of different months and areas. At last, the aerosol size distribution model of typical areas of eastern China is established..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 11, 2021
- Vol. 6, Issue 2, 154 (2011)
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