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北京市大气SO2、NO2和O3的激光雷达监测实验 总被引:4,自引:1,他引:3
目前监测网中大部分SO2、NO2和O3监测设备为地基点式仪器.该种设备不能获得大气SO2、NO2和O3的空间分布信息.SO2、NO2和O3的空间分布数据在习惯上一般是通过球载探测仪来获取.但通过球载仪获得的数据时间和空间分辨率都较差.中科院安徽光机所已开发研制完成了车载测污激光雷达系统.该系统能进行大气SO2、NO2和O3进行三维空间扫描测量.利用该系统2001年12月27日至2002年1月27日期间于北京市进行了大气SO2、NO2和O3的监测实验,首次给出了北京市近地面层大气SO2、NO2和O3的激光雷达测量数据.测量数据与地面仪器的监测数据进行了比较,结果表明车载测污激光雷达系统的测量数据是合理可靠的. 相似文献
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Henderson S.W. Suni P.J.M. Hale C.P. Hannon S.M. Magee J.R. Bruns D.L. Yuen E.H. 《Geoscience and Remote Sensing, IEEE Transactions on》1993,31(1):4-15
The development of a coherent laser radar system using 2-μm Tm and Tm, Ho-doped solid-state lasers, which is useful for the remote range-resolved measurement of atmospheric winds, aerosol backscatter, and differential absorption lidar (DIAL) measurements of atmospheric water vapor and CO2 concentrations, is described. Measurements made with the 2-μm coherent laser radar system, advances in the laser technology, and atmospheric propagation effects on 2-μm coherent lidar performance are discussed. Results include horizontal atmospheric wind measurements to >20 km. vertical wind measurements to >5 km, near-horizontal cloud returns to 100 km, and hard target (mountainside) returns from 145 km 相似文献
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差分吸收激光雷达测量环境SO2 总被引:5,自引:1,他引:5
提出了一种新的差分吸收激光雷达(DIAL)技术探测大气环境SO2。利用Nd:YAG激光器的四倍频266.0nm抽运甲烷和氘气,可以获得它们的一级斯托克斯拉曼频移波长288.38nm和289.04nm。SO2对波长为289.04nm的激光吸收较强,对288.38nm的激光吸收较弱,波长对288.38nm和289.04nm可用于大气SO2的测量。利用这种技术,建立了一台测量大气SO2的差分吸收激光雷达,并进行了实际测量和初步研究,对激光雷达测量SO2误差的主要来源进行了分析.并估计了测量误差的大小。差分吸收激光雷达的测量结果与仪器测量结果相比具有可比性。 相似文献
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探测云和气溶胶的机载双波长偏振激光雷达 总被引:2,自引:1,他引:2
针对机载双波长偏振激光雷达的技术特点,结合搭载遥感飞机的基本性能,分析了激光雷达的设计方法;仿真计算了激光雷达的配置参数;解决了激光雷达应用于航空平台的一些关键技术。通过实验取得了初步的结果,地基实验表明,激光雷达达到设计指标要求的探测能力。初步的飞行实验结果表明,激光雷达采用的关键技术符合航空平台关于体积、重量、功耗以及环境适应性的要求。利用激光雷达的主动探测能力,结合机上同时搭载的被动遥感仪器,将实现国家关注的大气成分及其环境要素的科学实验研究目标。 相似文献
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机载激光雷达的海陆波形分类对于沿海地区及其变化性质的研究至关重要。提出了一种在原始的机载激光雷达回波上使用深度学习进行分类的方法。构建全连接神经网络和一维卷积神经网络(CNN),在一个测量海域的数据集上进行训练和测试,最优模型获得了99.6%的分类精度。该最优模型对来自不同测量海域的数据进行分类,分类精度达到了95.6%,相比支持向量机方法,处理速度提高了约52%。结果表明:深度学习方法对机载激光雷达回波波形的分类具有较高的精度和速度,它可以进一步作为通过机载激光测深技术对海底种类进行分类的候选方法。 相似文献
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差分吸收激光雷达是高精度测量大范围二氧化碳浓度的有效手段。研究了机载路径积分差分吸收激光雷达测量二氧化碳柱线浓度的主要误差项,分析了这些误差项导致的二氧化碳柱线浓度反演误差。介绍了机载差分吸收激光雷达基本工作原理,并理论分析了大气温度、压强和水汽不确定性误差,激光频率稳定性和飞机姿态速度测量不确定性等系统误差,以及不同地表反射率产生的随机误差。分析结果表明:在二氧化碳浓度380 ppm(1 ppm=10-6)时,机载激光雷达二氧化碳柱线浓度综合测量误差约为0.71 ppm,满足1 ppm的二氧化碳柱线浓度高精度测量需求。 相似文献
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差分吸收相干激光雷达中偏振分集技术研究 总被引:3,自引:3,他引:0
为减小差分吸收相干激光雷达(DIAL)中偏振衰落对 回波信号功率反演精度影响,研究了偏振分集技术(PDT)在相干DIAL中 的作用,构建了利用STM32控制的双光束切换DIAL实验装置。依托构 建的装置,利用平衡探 测,分别采用PDT和一般外差探测完成多组次实验,应用单频检测方法得到20m光程下吸收 气体不同浓度下相干中频信号的振 幅值,并由此求解出on光和off光回波信号功率。对回波信号功率值差分信息与由HITRAN得 到的参考差分信息比较 发现:应用PDT能使探测分辨率提高4倍,对应到2km距离内,可以探测到3.5×10-6ppm的CO2浓度变化,满足了 气候研究所需的优于1%的精度要求,验证了PDT消除偏振衰落以及提高相干DIAL分辨精度的 作用。 相似文献
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Modeling lidar returns from forest canopies 总被引:7,自引:0,他引:7
Remote sensing techniques that utilize light detection and ranging (lidar) provide unique data on canopy geometry and subcanopy topography. This type of information will lead to improved understanding of important structures and processes of Earth's vegetation cover. To understand the relation between canopy structure and the lidar return waveform, a three-dimensional (3D) model was developed and implemented. Detailed field measurements and forest growth model simulations of forest stands were used to parameterize this vegetation lidar waveform model. In the model, the crown shape of trees determines the vertical distribution of plant material and the corresponding lidar waveforms. Preliminary comparisons of averaged waveforms from an airborne lidar and model simulations shows that the shape of the measured waveform was more similar to simulations using an ellipsoid or hemi-ellipsoid shape. The observed slower decay of the airborne lidar waveforms than the simulated waveforms may indicate the existence of the understories and may also suggest that higher order scattering from the upper canopy may contribute to the lidar signals. The lidar waveforms from stands simulated from a forest growth model show the dependence of the waveform on stand structure. 相似文献
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大气探测激光雷达技术综述 总被引:1,自引:0,他引:1
大气探测激光雷达具有可提供高时空分辨率、高探测精度和连续廓线数据的优势,已经成为大气探测强有力的工具。按照激光雷达探测技术分类,有米散射激光雷达、偏振激光雷达、拉曼激光雷达、差分吸收激光雷达、高光谱分辨率激光雷达、瑞利散射激光雷达、共振荧光激光雷达和多普勒激光雷达等,分别介绍了各类激光雷达探测的基本原理、发展历史及优缺点,以及其在探测大气气溶胶和云、水汽、温度、风、痕量气体、温室气体和污染气体等方面的应用。最后进行总结,并对激光雷达技术发展趋势进行了展望。 相似文献
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Development of efficient ultraviolet (UV) rare-gas halide excimer lasers has added new possibilities for laser radar (lidar) technique for monitoring atmospheric constituents. An experimental result of the observation of the stratospheric ozone layer by a XeCl laser (308 nm) based on the differential-absorption-lidar (DIAL) technique is described. The obtained ozone profile in an altitude range of 15- 25 km are in good agreement with those measured by radiosonde. The measurement error is analyzed for one-wavelength lidar. The accuracy is estimated to be 10-30 percent within an altitude range of 10-30 km and at a range resolution of 1 km or less. The accuracy and the resolution are higher than the Umkehr method. Recent progress of rare-gas halide lasers and their frequency conversion techniques as a transmitter for lidar are reviewed. Many powerful and reliable new sources are available in almost every wavelength over the near UV region. New applications of these UV sources to the lidar system are also briefly discussed, especially from the scientific field on the middle atmosphere. 相似文献
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小波变换与匹配滤波耦合的激光雷达弱信号处理 总被引:1,自引:0,他引:1
远距离激光雷达回波信号弱,干扰强,处理比较困难。距离越远,得到的有用信号就越弱。为了提高激光雷达检测距离,对弱信号进行数字信号处理就显得很重要。采用一般方法常将干扰信号判断成有用信号,从而影响了激光雷达的工作能力。夺文采用小波变换和匹配滤波耦合的方法对激光雷达弱信号进行处理,既能从强噪声中提取有用信号,又能有效的去掉强干扰信号。采用一台TEA—CO2激光器进行实验,当采样速率达到200MHz时,对于信噪比大于1.2的含噪信号能有效地去掉噪声和强干扰信号,在保持原信号特征的情况下,准确地提取出有效的弱信号。这就有效地提高了激光雷达的工作能力。 相似文献
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Volger P. Zhaoyan Liu Sugimoto N. 《Geoscience and Remote Sensing, IEEE Transactions on》2002,40(3):550-559
Spaceborne lidar observations have a great potential to improve our knowledge of the atmosphere. However, contrary to ground-based or airborne lidar measurements in observations from space multiple scattering (MS) has to be accounted for under all atmospheric conditions. A simple way to achieve this is to introduce the approximative MS factor F in the single scattering lidar equation. We determined F for measurements of aerosols, ice and water clouds as they were planned with the Japanese space lidar ELISE. We found that F is almost constant in cirrus clouds and in water clouds which are penetrable by lidar. In aerosol layers F depends on penetration depth, extinction coefficient and aerosol type. In comparison to LITE the MS factor is smaller (for aerosols and water clouds) or almost equal (cirrus) 相似文献
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