Journals >Journal of Atmospheric and Environmental Optics
Contents
2012
Volume: 7 Issue 5
11 Article(s)
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Research Article
Joint Probability Density Function Varying with Wind Speed and Direction in Hefei Area
Yan-hui WU, Yi WU, Zai-hong HOU, Cai-yun ZHANG, Fei LI, and Shou-chuan ZHANG
In photoelectricity scanning system, stagnation zoon of thermal blooming makes energy of laser propagation decrease through atmosphere. The probability of stagnation of thermal blooming is decided by joint probability of wind speed and direction of atmosphere. Based on the wind profile radar one hour average wind fieldIn photoelectricity scanning system, stagnation zoon of thermal blooming makes energy of laser propagation decrease through atmosphere. The probability of stagnation of thermal blooming is decided by joint probability of wind speed and direction of atmosphere. Based on the wind profile radar one hour average wind field data from May 2007 to June 2011, according to the least square method, Frechet, Gumbel and Weibull probability distribution were fitted. The fitting parameters, correlation coefficient and residual standard deviation were obtained. The optimal model was achieved by the comparison of different results. In condition of no good fitting result of above method, based on sample data, according to the characteristics of circular normal probability distribution, zonal wind and meridional wind average value and mean square deviation can be calculated. The relationship of wind field probability varying with wind speed and direction can be obtained so as to obtain probability for some wind field..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 7, Issue 5, 327 (2012)
Remote Sensing of Crosswind Speed bya Scintillometer in Boundary Layer
Yong-zhi TIAN, Jian-guo LIU, Yi-huai LU, and Hua-qiao Gui
Two optical scintillation methods of measuring the crosswind speed were investigated in the boundary layer. Then, the calculation formulas of wind measurements were proposed. The experiment was carried out at 330 m optical path. Finally the measurements were compared to the results of the sonic anemometer. The results Two optical scintillation methods of measuring the crosswind speed were investigated in the boundary layer. Then, the calculation formulas of wind measurements were proposed. The experiment was carried out at 330 m optical path. Finally the measurements were compared to the results of the sonic anemometer. The results showed two optical scintillation methods were both suitable to determine the windspeed, but the slope technique was more reliable than the peak technique at the time during sunrise and sunset transitions. It was also found that better results can be obtained with the longer time-average. The results demonstrated that a large aperture scintillometer can be used to measure both sensible heat flux and crosswind, so it would be widely applied in evaluation of mass exchange in the atmosphere..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 7, Issue 5, 333 (2012)
Effect of Illumination on Secondary Organic Aerosol Formation from Ozonolysis of Limonene
Zhi LIU, Chang-jin HU, Yue CHENG, Gang PAN, Xiao-hong ZHENG, Xue-jun GU, Wei-xiong ZHAO, and Wei-jun ZHANG
As an important biogenic volatile organic compound, ozonolysis of limonene is a significant source of atmospheric secondary organic aerosol (SOA). Quantitative research on ozonolysis of limonene was reported under both dark and UV-illuminated conditions in the self-made smog chamber. The time evolutions of limonene preAs an important biogenic volatile organic compound, ozonolysis of limonene is a significant source of atmospheric secondary organic aerosol (SOA). Quantitative research on ozonolysis of limonene was reported under both dark and UV-illuminated conditions in the self-made smog chamber. The time evolutions of limonene precursor, SOA mass concentration as well as SOA particle size distributions were investigated continuously, and the yield of SOA was analyzed according to the gas/particle partitioning theory. It is shown that exposure to UV light reduces SOA yield by 10%～16% under corresponding conditions, and it is proposed that gas-phase photolysis of some intermediate or final products may play a key role in the decline of yields in the presence of UV light..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 7, Issue 5, 348 (2012)
Counting Achievement of Lidar’s Single Photon Counter
Wen-hua MEI, Jian-guo LIU, Tian-shu ZHANG, and Yi-bin FU
As the data acquisition component of lidar, single photon counter is designed to achieve the PMT output pulse signal count, and real-time upload the data to the computer. Because the rise time of the pulse signal is very short and the volume of data is very large, using CPLD as the counter and controller, using gated dAs the data acquisition component of lidar, single photon counter is designed to achieve the PMT output pulse signal count, and real-time upload the data to the computer. Because the rise time of the pulse signal is very short and the volume of data is very large, using CPLD as the counter and controller, using gated dual channel seamless counting method, the system can achieve 50 ns gate width resolution. Using a piece of 32 K×16 bit SRAM as cache can meet the requirements of maximum counts of 65535 per 50 ns time resolution. Using the USB as data transmission interface can meet the design requirements of high speed and real-time very well..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 7, Issue 5, 364 (2012)
System Design for Integrating Nephelometer Based on LED Light Source
Yu-di WU, Jian-guo LIU, Fan LU, Hua-qiao GUI, and Ya-ping WANG
Scattering coefficient is one of the most important parameters of the aerosol optical properties. A kind of integrating nephelometer for measuring scattering coefficient is developed to investigate the aerosol optical properties. Principles and the system design of the system are presented, the optimal design of the opScattering coefficient is one of the most important parameters of the aerosol optical properties. A kind of integrating nephelometer for measuring scattering coefficient is developed to investigate the aerosol optical properties. Principles and the system design of the system are presented, the optimal design of the optical chamber and the light source are proposed. Experimental results show that the correlation coefficient between scattering coefficient measured by the nephelometer and visibility measured by the forward-scattering visibility sensor was 0.834. It illustrates that the system is compact, low cost and reliable..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 7, Issue 5, 370 (2012)
Selection of Two-Color Wavelengths in Colorimetric Temperature Measurement of Uncooled IRFPA
Hai-bin WU, Tie-yi ZHANG, Hou-wei ZHOU, Fei WANG, and Ying-wei ZHOU
The operating wavelength of the uncooled infrared focal plane arrays(uncooled IRFPA) is 8～14 μm. The uncooled IRFPA can obtain a specific wavelength of radiant exitance by adding a specific wavelength filter. Then the colorimetric temperature measurement is used to complete the industrial low temperature measurement. TThe operating wavelength of the uncooled infrared focal plane arrays(uncooled IRFPA) is 8～14 μm. The uncooled IRFPA can obtain a specific wavelength of radiant exitance by adding a specific wavelength filter. Then the colorimetric temperature measurement is used to complete the industrial low temperature measurement. The basic principles of colorimetric temperature measurement of uncooled IRFPA is introduced, the theoretical basis for using the double wavelength colorimetric measurement temperature principle in range of 8～14 μm is discussed in detail, and the MATLAB simulation is used to determine the principle of the best double wavelength selection of the industrial low temperature measurement. Finally, the T－R(T) image of dual wavelength(8.8 μm, 10.6 μm) is simulated, and the results can meet the requirements of the temperature measurement accuracy..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 7, Issue 5, 385 (2012)
[in Chinese]
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 7, Issue 5, 1 (2012)
Analysis for Atmospheric Ozone and Nitrogen Oxide in Beijing Area
Shi-guo ZHANG, Ke-e YUAN, Shun-xing HU, Jian HUANG, and Ying-jian WANG
At upper atmosphere, ozone can absorb ultraviolet and protect life on earth, but at low altitude and near-ground ozone is polluting gas endangering human health, animal and plant growth. Nitrogen oxides are also polluting gases in the air. Ozone and nitrogen oxides can be transformed into each other. Research on the reAt upper atmosphere, ozone can absorb ultraviolet and protect life on earth, but at low altitude and near-ground ozone is polluting gas endangering human health, animal and plant growth. Nitrogen oxides are also polluting gases in the air. Ozone and nitrogen oxides can be transformed into each other. Research on the relationship between the two gas is of great significance. Based on EC9810A ozone analyzer and EC9841 nitrogen oxide analyzer, the observation at Chinese Research Academy of Environment Sciences in Beijing during December, 2011 is carried out, and the distributed characteristics of ozone and nitrogen oxide during day and night were obtained. The analysis shows obvious distributed characteristics of ozone and nitrogen oxide during day and night. At daytime, concentration of ozone increases at morning, and then decreases at afternoon. At night, it keeps a steady status and the concentration is less than that in daytime. The trend of nitrogen oxide is opposite to ozone. At daytime, the concentration of nitrogen oxide decreases at morning and then increases at afternoon. The change of ozone has the relationship with meteorology. On sunny day, the concentration of ozone has a sharp increase, but at cloudy day or rainy day, has a slow increase. And the concentration of ozone also changes with the season, it is higher in spring than that in winter. The main reason that results in the concentration increase of nitrogen oxide is the emission of automobile exhaust and other waste gas. AML-3 mobile lidar developed by Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences is used to measure the vertical profile. Variation of mean ozone concentrations from 500 m to 1000 m has a consistent trend with ozone analyzer..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 7, Issue 5, 321 (2012)
Accuracy of MM5 Wind Field Data Based on Passive DOAS Territorial Monitoring
Jing-wen YANG, Ang LI, Pin-hua XIE, Xue-song ZHAO, Feng-cheng WU, and Yang WANG
The mobile passive DOAS measurement for emissions of pollutants is widely used recently, but the acquisitions of wind field data is always a challenge. Comparative analyses of three kinds of wind field data under different atmospheric stability conditions are carried out by Pasquill-Turner stability classification methThe mobile passive DOAS measurement for emissions of pollutants is widely used recently, but the acquisitions of wind field data is always a challenge. Comparative analyses of three kinds of wind field data under different atmospheric stability conditions are carried out by Pasquill-Turner stability classification method. Comparisons were carride out between the wind field collected from two different measurements and the wind field of micro-scale atmospheric modeling with the different stability of atmosphere. Under weak instable atmospheric conditions, wind speed data of MM5 model were consistent with the wind speed data of ground from meteorological station and wind profile radar, the contrast of wind direction data has a slight error. Under neutral atmospheric condition, the wind data of MM5 (10 m, 150 m) were consistent with the observed data from weather station and wind profile radar respectively. The results show that, they have high correlativity (>0.6), and the error is small. Therefore, the wind field data of MM5 is used for the mobile passive DOAS measurement of emissions of pollutants under the neutral atmospheric condition, to compensate the deficiencies of data caused by constrained weather measurements..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 7, Issue 5, 338 (2012)
Retrieval of Aerosol Optical Thickness over Bright Surface Areas Using MODIS Data
Zhao-liang LIU, and Jin-ji MA
It is difficult to determine surface reflectance over bright surface. Based on the geometric optics model theory, it can be assumed that on the same day on the same ground two different band ratio approximately equal in different years. According to the history of the MOD09 blue band surface reflectance, the MOD02 seveIt is difficult to determine surface reflectance over bright surface. Based on the geometric optics model theory, it can be assumed that on the same day on the same ground two different band ratio approximately equal in different years. According to the history of the MOD09 blue band surface reflectance, the MOD02 seventh band surface reflectance and the MOD02 seventh band surface reflectivity, the surface reflectance of retrieval region can be obtained, and 6S radiation transmission is combined to build look-up table, to retrieve aerosol optical thickness of Beijing Area. Beijing AERONET site observations data is used to verify the outcome, the results have a good consistency with AERONET data over bright surface, and the error is less than 30%..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 7, Issue 5, 358 (2012)
Real-Time Auto-Adjust System of Large-Scale CCD Light Integration Time Based on FPGA
Kai-fu HU, and Shuang-bao WANG
In order to improve the system’s adaptability, detecting ability and accuracy of measurement, the system needs to adjust charge-coupled device(CCD) light integration time with automatic real-time large-scale according to actual light intensity. On the basis of analyzing the characteristics, the working process and the In order to improve the system’s adaptability, detecting ability and accuracy of measurement, the system needs to adjust charge-coupled device(CCD) light integration time with automatic real-time large-scale according to actual light intensity. On the basis of analyzing the characteristics, the working process and the driven timing of the TCD1304AP type of linear CCD, the self-adaptive system of CCD light integral time real-time large range based on field programmable gate arrays(FPGA) was designed. The light integral time calculation algorithm was studied and analyzed. The EP1C20F400C8 as a hardware platform, and the algorithm CCD driven timing was achieved by the Verilog language. The design was compiled, and integrated by the QuartusII, and simulated by the Modelsim. The design was tested with natural light and LED light source. Experimental results indicate that the light integration time is from 10 μs to 10 s or above, the minimum adjustable time is 0.25 μs, and the system can meet the requirement of light real-time large-scale stepless adjustment..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 7, Issue 5, 376 (2012)
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