Journals >Journal of Atmospheric and Environmental Optics
Contents
2009
Volume: 4 Issue 6
11 Article(s)
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Research Article
ARL-1 Raman Lidar System for Atmospheric CO2Measurements
Shun-xing HU, Pei-tao ZHAO, Shao-lin WANG, Kai-fa CAO, Xin FANG, Guang-qiang FAN, Min WANG, Bo ZHAO, Huan-ling HU, and Ying-jian WANG
ARL-1 Raman lidar system developed in Anhui Institute of Optics and Fine Mechanics was introduced for atmospheric CO2 measurements. It is based on third harmonic of Nd:YAG laser. This system emits laser beam at wavelength of 354.7 nm into atmosphere and collects Raman backscattering lights from atmospheric N[EQUATION] ARL-1 Raman lidar system developed in Anhui Institute of Optics and Fine Mechanics was introduced for atmospheric CO2 measurements. It is based on third harmonic of Nd:YAG laser. This system emits laser beam at wavelength of 354.7 nm into atmosphere and collects Raman backscattering lights from atmospheric N[EQUATION] and CO[EQUATION] stimulated by laser beam. Mixing ratio profile of CO2 can be calculated with Raman backscattering signals of N[EQUATION] and CO2. In ARL-1 Raman lidar system, a setup for lidar constant calibration was designed. The experimental result shows that the stability of LED light intensity can reach up to 99.5%. Atmospheric CO2 measurements in planetary boundary layer were carried out with the Raman lidar system..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 12, 2021
- Vol. 4, Issue 6, 401 (2009)
Research on Doppler Radar Spectral Width and Variability of Turbulent Dissipation Rate
Cai-yun ZHANG, De-bao DONG, and Ning-quan WENG
Turbulent kinetic energy dissipation rate (turbulent dissipation rate) is an important parameter of the turbulence. There is a new measurement on the turbulence, which estimats the turbulent dissipation rate using the spectral width of wind profiler. Based on studying the influencing factor on the spectral width of echTurbulent kinetic energy dissipation rate (turbulent dissipation rate) is an important parameter of the turbulence. There is a new measurement on the turbulence, which estimats the turbulent dissipation rate using the spectral width of wind profiler. Based on studying the influencing factor on the spectral width of echo signal of airdar16000 wind profiler radar, and extracting the spectral width contributing by turbulence, the turbulent dissipation rate can be estimated. Results show that the value of spectral width from turbulence is below 0.5 m[EQUATION]s[EQUATION], and the oblique beams are more reliable than the vertical beam, and the turbulent dissipation rate distributes between 10[EQUATION]m[EQUATION]s[EQUATION] and 10[EQUATION]m[EQUATION]s[EQUATION]. It decreases with the increase of the height. The result accords with the theory, so it is feasible to estimate the dissipation rate from wind profiler radar..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 12, 2021
- Vol. 4, Issue 6, 406 (2009)
Experimental Determination of the Calibration Factor of Polarization-Mie Lidar
Zhen-zhu WANG, Bo LIU, Bang-xin WANG, and Dong LIU
A ground-based polarization-Mie lidar has been developed to measure backscattering signals from the atmosphere and linear depolarization ratios at 532 nm. To retrieve depolarization properties of clouds and aerosols, the calibration factor of two polarization channels at 532 nm must be calculated. Three different experA ground-based polarization-Mie lidar has been developed to measure backscattering signals from the atmosphere and linear depolarization ratios at 532 nm. To retrieve depolarization properties of clouds and aerosols, the calibration factor of two polarization channels at 532 nm must be calculated. Three different experimental methods are presented to determine the calibration factor in this polarization-Mie lidar. Some measured examples are presented and discussed. Experimental and CALIPSO results indicate that these methods are feasible..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 12, 2021
- Vol. 4, Issue 6, 414 (2009)
Study on Flow Properties of Convective Boundary Layer over Thermally Inhomogeneous Surface
Ren-min YUAN, Tao LUO, Xu-ping WU, Chao LU, Jian-ning SUN, and Hui-zhi LIU
The simulation of convective boundary layer(CBL) over thermally inhomogeneous surface is made using water tank for study on flow properties. By imitating the mosaic method in the numerical simulation, the low thermal conductivity materials are placed on the bottom of the water tank so that heating from the bottom is inThe simulation of convective boundary layer(CBL) over thermally inhomogeneous surface is made using water tank for study on flow properties. By imitating the mosaic method in the numerical simulation, the low thermal conductivity materials are placed on the bottom of the water tank so that heating from the bottom is inhomogeneous. The CBL height and velocity scales are obtained by temperature profiles and collimated-laser system. PTV technique is used for retrieval of two dimensional flow fields. The flow fields have complex structures and scales. Compared with the homogeneous surface, the surface inhomogeneous heating makes the mixed layer strengthen turbulence organization and has stable local circulations. The variations of statistics of velocities with height are different from the homogeneous situation. In order to analyze the contribution of thermal inhomogeneity to the horizontal advection, the turbulent advections for turbulent kinetic energy are calculated. Results show that at the beginning and developing period the horizontal advection is large due to the large heating difference and the horizontal advection becomes weak at the end of development of CBL due to the little heating difference. Based on these results, it can be concluded that the horizontal advection depends on the thermally inhomogeneous intensity..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 12, 2021
- Vol. 4, Issue 6, 421 (2009)
Analysis of the Influence on Remote Sensing Imaging under Different Atmospheric Conditions by Monte-Carlo Method
Shang-yu DU, Xian-hua WANG, and Zhen WANG
With the development of remote sensing space resolution, the atmosphere as impassable medium of remote sensing imaging made the resolution decrease. For quantitative analysis on the influence of different atmospheric conditions, the Monte-Carlo theory and atmospheric radiative transfer by Monte-Carlo method was introduWith the development of remote sensing space resolution, the atmosphere as impassable medium of remote sensing imaging made the resolution decrease. For quantitative analysis on the influence of different atmospheric conditions, the Monte-Carlo theory and atmospheric radiative transfer by Monte-Carlo method was introduced firstly, and the photons diffusion in different conditions was simulated. Atmospheric point spread function is studied under different conditions of wavelength, different visibility, different remote sensor height, different asymmetry indices of aerosol particle and different observation angles based on standard atmospheric models of Modtran. Experimental results indicate that different atmospheric conditions have some influence on data quality of remote sensing image..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 12, 2021
- Vol. 4, Issue 6, 441 (2009)
Polarized Reflectance Characteristics of Red Soil with Different Moisture
Ya-nan LI, Xiao-bing SUN, Yan-li QIAO, Qiao ZHANG, and Jin HONG
Different state of polarization can be generated by different soil moisture, which relates closely to the wavelength, the roughness of the soil, the component of soil, and the incident zenith angle. According to Kodis[EQUATION] theory for scattering by a rough surface, a simple formula that relates the degree of polariDifferent state of polarization can be generated by different soil moisture, which relates closely to the wavelength, the roughness of the soil, the component of soil, and the incident zenith angle. According to Kodis[EQUATION] theory for scattering by a rough surface, a simple formula that relates the degree of polarization of soil to incident zenith angle, viewing angle and refractive index is obtained. Polarized reflectance data of different moisture red soil is collected with a polarimetric instrument and compared with the calculated results. Preliminary results of the change in degree of polarization for red soil with different moisture are presented. The results are significant for satellite agricultural remote sensing..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 12, 2021
- Vol. 4, Issue 6, 448 (2009)
Nondestructive Testing Based on Backward Wave Oscillator Continue Terahertz Wave Imaging System
Hong-yang YUAN, Xin-hao GE, and Cun-lin ZHANG
The terahertz(THz) imaging system with a backward wave oscillator(BWO) is a new approach to nondestructive testing. The sample is placed on an [EQUATION]-[EQUATION] two-dimensional stage controlled by a computer. The intensity information of the terahertz wave after passing sample is collected by a pyroelectric detectoThe terahertz(THz) imaging system with a backward wave oscillator(BWO) is a new approach to nondestructive testing. The sample is placed on an [EQUATION]-[EQUATION] two-dimensional stage controlled by a computer. The intensity information of the terahertz wave after passing sample is collected by a pyroelectric detector, and then it can image by the computer. A number of potential imaging applications are demonstrated using the 0.71 THz radiation, including nondestructive real-time testing for plastic bus fare card, campus debit card and various articles contained in an envelop. The spatial resolution ability of the system is measured to be 1.5 mm. And the digital image processing is presented based on the result of the imaging system. The conclusion indicates that the image results are more distinct, after the optimization, which can improve the ability of continuous wave imaging technology. The results reveal that the BWO THz imaging system is very practical and effective in nondestructive identification and security inspections applications in future..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 12, 2021
- Vol. 4, Issue 6, 456 (2009)
A Novel Gas Sensor With Optical Filter Sensor Based on Micro-Ring Resonator
Xing-hua TU
Optical fiber gas sensing technology based on micro-ring resonator is a new measuring technique, which has a wide applicable prospect in fields of industrial production, environment monitoring and medical science. There is a micro-ring structure in the gas sensor based on absorption spectroscopy, which has some advantaOptical fiber gas sensing technology based on micro-ring resonator is a new measuring technique, which has a wide applicable prospect in fields of industrial production, environment monitoring and medical science. There is a micro-ring structure in the gas sensor based on absorption spectroscopy, which has some advantages of the whole compact fabric and perfect wavelength selectivity. According to numerical analysis about the characteristic of spectrum absorption of specific gas and micro-ring resonator, a normal design of optical fiber detection system of gas is presented and discussed, which has micro-ring optical filter. The theory of micro-ring resonator is mainly introduced. And the relations among the size of the micro-ring, resonance wavelength and freedom spectrum range are discussed in detail..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 12, 2021
- Vol. 4, Issue 6, 462 (2009)
Performance Characteristics of Novel Porous Silicon at Ambient Condition
Cheng-yin SHEN, Xiao-qin XI, Qiao-ling DENG, and Yan-nan CHU
For the development of the ionizer with low discharge voltage and the photounit at ambient condition, a novel porous silicon(PS) fabricated by combining the electrochemical anodization in HF solution under light with hydrothermally iron-passivated is introduced. The characteristics of electron emission and photo-electrFor the development of the ionizer with low discharge voltage and the photounit at ambient condition, a novel porous silicon(PS) fabricated by combining the electrochemical anodization in HF solution under light with hydrothermally iron-passivated is introduced. The characteristics of electron emission and photo-electricity response at ambient condition were studied. The results show that this PS can emit electrons steadily for 2[EQUATION]3 min, and there is positive output voltage ([EQUATION] 120 mV) in the dark and the negative output voltage ([EQUATION]30 mV) under illumination. This indicates that the novel PS holds a potential to be exploited as the ionizer with low discharge voltage and the special photounit at ambient condition..
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 12, 2021
- Vol. 4, Issue 6, 469 (2009)
[in Chinese]
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 12, 2021
- Vol. 4, Issue 6, 474 (2009)
[in Chinese]
Journal of Atmospheric and Environmental Optics
- Publication Date: Oct. 12, 2021
- Vol. 4, Issue 6, 1 (2009)
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