Journals >Journal of Atmospheric and Environmental Optics
Contents
2017
Volume: 12 Issue 5
11 Article(s)
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[in Chinese]
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 12, Issue 5, 1 (2017)
Study of Aerosol Optical Depth and Angstrm Exponent in the Northwest of China Based on MODIS Product
Shiwei ZHAO, and Xiaoqing GAO
Analysis of spatio-temporal characteristics and correlations between aerosol optical depth(AOD) and Angstrm exponent over northwest was analyzed based on MODIS C6 product from 2006 to 2015. The results showed that the high AOD occurred in the area of Southern Xinjiang and Guanzhong region of Shaanxi Province, the soutAnalysis of spatio-temporal characteristics and correlations between aerosol optical depth(AOD) and Angstrm exponent over northwest was analyzed based on MODIS C6 product from 2006 to 2015. The results showed that the high AOD occurred in the area of Southern Xinjiang and Guanzhong region of Shaanxi Province, the south of Qinghai and Gansu Province existed low value. High Angstrm exponent occurred in the east of the northwest, and spatial distribution was quite different in the north of Xinjiang. The annual mean AOD was 0.208±0.011, Angstrm exponent was 1.185±0.025. AOD showed a downward trend during 2010 to 2015, and Angstrm exponent was on the rise during 2008 to 2015. AOD and Angstrm exponent were opposite to the seasonal changes, the largest AOD was in spring, the smallest in autumn, just the reverse to Angstrm exponent. The monthly mean AOD appeared in April, which was 0.35 ± 0. 038, the smallest in October was 0.13 ± 0.009, Angstrm exponent was the largest in December, which was 1.34 ± 0.35, the lowest in April was 0.97 ± 0.054; AOD and Angstrm exponent had negative correlation, the highest correlation in spring, which was -0.77, the lowest correlation in winter, which was -0.28. The correlation between AOD and the Angstrm wavelength index in different seasons was analyzed, the results indicated that coarse and fine particle size aerosol particles occupied a certain proportion, mainly in small particle size of the smoke particles, dust aerosol particles also occupy a certain proportion. Aerosol emission was increased from spring to winter..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 12, Issue 5, 321 (2017)
Numerical Evaluation of Precision of Atmospheric Molecular Absorption Calculated by MODTRAN5 Band Model
Li MA, Congming DAI, Chaoli TANG, Xikui MIAO, and Heli WEI
The MODTRAN5 radiation transport model is advanced over earlier versions of the MODTRAN model. The spectral resolution has been improved from 2 cm-1 to 0.2 cm-1. To validate the precision of atmospheric molecular absorption calculated by MODTRAN5 band model, the atmospheric molecular absorption spectral transmittance iThe MODTRAN5 radiation transport model is advanced over earlier versions of the MODTRAN model. The spectral resolution has been improved from 2 cm-1 to 0.2 cm-1. To validate the precision of atmospheric molecular absorption calculated by MODTRAN5 band model, the atmospheric molecular absorption spectral transmittance is calculated by using the accurate line-by-line atmospheric transfer model (LBLRTM), then as a reference to the results of MODTRAN5. The results show that the MODTRAN5 coincides with LBLRTM at most cases, and the root-mean-square error (RMSE) of atmospheric spectral transmittance between the MODTRAN5 and LBLRTM is almost below 0.02. But at some spectral region, the difference can be over 0.03. As the largest difference occurs at 4.3 μm wavelength which is the border of strong absorption band of carbon dioxide, the RMSE is 0.0377..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 12, Issue 5, 332 (2017)
Characteristics of Coherent Structures of Atmospheric Turbulence in High Latitude Based on Wavelet Analysis
Zekun YANG, Gang SUN, Qing LIU, Xuebin LI, and Ningquan WENG
Fluctuation dates of wind speed and temperature are analyzed by using spectral analysis and wavelet analysis. Then the coherent structures of atmospheric turbulence at different heights are obtained. They are used to identify the characteristic scales of coherent structures in time series. They are also used to extractFluctuation dates of wind speed and temperature are analyzed by using spectral analysis and wavelet analysis. Then the coherent structures of atmospheric turbulence at different heights are obtained. They are used to identify the characteristic scales of coherent structures in time series. They are also used to extract spatial characteristics of coherent structures of atmospheric turbulence in high altitude by combining structural parameters of atmospheric refractive index C2n, and the spatial characteristics like turbulence intensity and turbulent layer thickness were extracted. It is found that with the change of the height, the turbulence is manifested by the alternation of the strong stratification and the weak stratification. As the height increases, the turbulence duration becomes shorter and the thickness of the turbulent layer becomes smaller. Strong turbulences of small scale exist in weak turbulence of large scale. They have relatively dense distribution, short duration, and small thickness. The high altitude atmospheric turbulence in this measurement is found to have a clear phenomenon of strong or weak stratification in the 5～15 km. At the height of 6～10 km, there are four strong turbulence layers, and the thickness of the turbulent layer is about 500 m..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 12, Issue 5, 340 (2017)
Measurement of Refractive Index of Aerosol Particles Using Aerosol Time-of-Flight Mass Spectrometer
Hua RONG, Xuejun GU, Zuoying WEN, Yupeng ZHU, Xiaofeng TANG, Weixiong ZHAO, and Weijun ZHANG
Aerosol time-of-flight mass spectrometer (ATOFMS) is used to measure the refractive index of aerosol particles. First of all, diameter and light scattering intensity of aerosol particles are measured through the self-developed ATOFMS. Then the function relation of theoretical luminous flux accepted by photo multiplier Aerosol time-of-flight mass spectrometer (ATOFMS) is used to measure the refractive index of aerosol particles. First of all, diameter and light scattering intensity of aerosol particles are measured through the self-developed ATOFMS. Then the function relation of theoretical luminous flux accepted by photo multiplier tube (PMT) with aerosol particles size and the refractive index is deduced through the Mie scattering theory combined with the ATOFMS geometric model of light scattering experiment. The refractive index is retrieved by comparing the experimental aerosol particles average light scattering intensity with Mie scattering theory. The result shows that the method is reasonable compared with the actual sample data parameters..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 12, Issue 5, 349 (2017)
Measurement of CO2 Concentration Based on Wavelength Modulation Spectroscopy Technology
Xuemei WANG, and Shi LIU
Based on tunable diode laser absorption spectroscopy, combined with wavelength modulation spectroscopy technology, different volume concentration CO2 was selected to be measured. The influence of modulation voltage and modulation frequency of sine wave on second harmonic signals was observed. Results show that the signBased on tunable diode laser absorption spectroscopy, combined with wavelength modulation spectroscopy technology, different volume concentration CO2 was selected to be measured. The influence of modulation voltage and modulation frequency of sine wave on second harmonic signals was observed. Results show that the signals perform well when modulation voltage is 0.25 V and modulation frequency is 10 kHz. CO2 with different concentration was measured by using the single optical system set up in the laboratory. The results show that the correlation coefficient of the concentration and the peak value of the second harmonic signals is 0.998. Moreover the detection limit is 450 ppm. The experiment result provides definite basis for choosing modulation parameters of such system and can build foundation for industry application..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 12, Issue 5, 356 (2017)
Characteristics and Source Apportionment of Volatile Organic Compounds in Hefei Dongpu Reservoir
Jinghao CAO, Meng KANG, Xue ZOU, Wenzhao ZHOU, Yan LU, Chengyin SHEN, Chaoqun HUANG, and Yannan CHU
Solid phase micro extraction and gas chromatography mass spectrometry (SPME/GC-MS) was used to detect the ambient volatile organic compounds (VOCs) in Hefei Dongpu Reservoir, China, and the composition and variation characteristics of VOCs in the area were investigated. The result shows that these VOCs are mainly compoSolid phase micro extraction and gas chromatography mass spectrometry (SPME/GC-MS) was used to detect the ambient volatile organic compounds (VOCs) in Hefei Dongpu Reservoir, China, and the composition and variation characteristics of VOCs in the area were investigated. The result shows that these VOCs are mainly composed of benzene series, aldehydes, ketones and alkanes. Principal component analysis /absolute principal component scores (PCA/APCS) model was used to analyze the source of the VOCs. The result shows that there are 4 main sources of the VOCs, such as automobile emission sources account for 38.9%, chemical reagents sources account for 49.48%, industrial production sources account for 8.13% and medical alcohol evaporation sources account for 3.49%, respectiely..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 12, Issue 5, 362 (2017)
Influence of Noise on Atmospheric Trace Gas Distribution Reconstruction
Minhong WEI, Suwen LI, Xuan Zhu, Dezhao DOU, and Fen SHAO
For the noise problem of two-dimensional concentration distribution reconstruction of trace gases in the atmosphere, the method of numerical simulation is adopted to study the influence of noise on the spatial distribution reconstruction of atmospheric trace gases by the differential absorption spectrum tomography. TheFor the noise problem of two-dimensional concentration distribution reconstruction of trace gases in the atmosphere, the method of numerical simulation is adopted to study the influence of noise on the spatial distribution reconstruction of atmospheric trace gases by the differential absorption spectrum tomography. The noise model is established, the algebraic iterative reconstruction algorithm (ART) and simultaneous iterative reconstruction algorithm (SIRT) are researched, and the influence of noise on the reconstruction effects of the two kinds of reconstruction algorithm is also researched respectively. The error index Ea can be reduced from 0.1080 to 0.0182 by reconstruction of ART algorithm, and the error index Ea can be reduced from 0.0476 to 0.0102 by reconstruction of SIRT algorithm. The results show that with the increase of random noise, the abnormal degree of reconstruction image is more and more serious. From the relative error indicators of reconstruction, with the increase of signal-to-noise ratio, reconstruction of relative error is smaller and smaller. Therefore, noise should try to be avoided in field reconstruction experiment..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 12, Issue 5, 371 (2017)
Design and Implementation of Android-Based Cross-Platform Atmospheric Measuring Equipment Remote Control System
Guangpu BAO, Xiaoqin LIU, and Heli WEI
In recent years, the Android-based remote control system has made great progress in industrial control, nuclear science and technology, internet of things and other areas, but the current application is rare in the field of atmospheric science. For the demand of the remote control in the atmospheric science field experIn recent years, the Android-based remote control system has made great progress in industrial control, nuclear science and technology, internet of things and other areas, but the current application is rare in the field of atmospheric science. For the demand of the remote control in the atmospheric science field experiment, combined with the advantages of Android devices in the remote control field, an Android-based atmospheric measuring equipment remote control system was proposed. The system is based on C/S architecture, and a more stable and efficient cross-platform communications framework was designed based on the IOCP model and TCP Socket. Finally the remote control of the multi-Android equipment to the multi atmospheric measuring equipment was realized..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 12, Issue 5, 377 (2017)
Design of Intelligent Sorting Machine Control System Based on PLC
Jun LI, Xiaoqin LIU, Yi WU, Laian QIN, Lulu HU, and Chao MU
As there is no independent intellectual property rights for domestic semiconductor sorter system now, a program for designing an intelligent sorting machine control system based on PLC was put forward. The intelligent sorting machine system which puts IPC as the host computer, Yaskawa MP2310 as slave, constitutes closeAs there is no independent intellectual property rights for domestic semiconductor sorter system now, a program for designing an intelligent sorting machine control system based on PLC was put forward. The intelligent sorting machine system which puts IPC as the host computer, Yaskawa MP2310 as slave, constitutes closed loop control system through servo driver which controls the servo motor. It not only achieves accurate position control but also meets the accuracy requirements of the semiconductor chip that is sorted. First of all, a flow chart about the loader part was presented, then the process about the loader part was introduced in detail, and some typical PLC program of loader part was given. The most important is that the problems of teaching the table, fast sorting chips were resolved. The system is reasonable, reliable, stable in actual use..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 12, Issue 5, 386 (2017)
Software Design Based on TDLAS for Two-Dimensional Temperature Field Distribution Inversion
Fuduo CHEN, Jianguo LIU, Ruifeng KAN, Zhenyu XU, Huihui XIA, and Xiang CHEN
The visualization of 2D temperature field distribution inversion software plays an important role in the distribution of temperature field reconstruction. Based on tunable diode laser absorption spectroscopy (TDLAS) technology, combined with the algebraic reconstruction technique (ART) and Python programming language, The visualization of 2D temperature field distribution inversion software plays an important role in the distribution of temperature field reconstruction. Based on tunable diode laser absorption spectroscopy (TDLAS) technology, combined with the algebraic reconstruction technique (ART) and Python programming language, based on two groups of integral absorbance, the visualization software of two-dimensional temperature field distribution was designed. Combined with laser absorption spectroscopy and computed tomography method, the two-dimensional temperature field reconstruction algorithm was packaged. Then the visual interface was added and the original distribution and the interpolation distribution of the two-dimensional temperature field reconstruction were achieved. The reconstructed results are of higher temperature of central zone and lower in edge, which indicates that the ART algorithm and TDLAS technology can be combined to achieve the 2D temperature field and overcome the defect of TDLAS line-of-sight measurement..
Journal of Atmospheric and Environmental Optics
- Publication Date: Jan. 01, 1900
- Vol. 12, Issue 5, 393 (2017)
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