• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >A High Spectral Resolution Lidar at 532 nm for simultaneous measurement of atmospheric state and aerosol profiles using iodine vapor filters.
【24h】

A High Spectral Resolution Lidar at 532 nm for simultaneous measurement of atmospheric state and aerosol profiles using iodine vapor filters.

机译：532 nm的高光谱分辨率激光雷达，可使用碘蒸气滤光片同时测量大气状态和气溶胶剖面。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This dissertation presents a High Spectral Resolution Lidar (HSRL) to simultaneously measure vertical profiles of atmospheric temperature, pressure, aerosol to molecular backscatter ratio, and aerosol extinction coefficient. The lidar uses a narrow band pulsed laser source operated at 532 nm and iodine vapor filters are used as narrowband notch filters in the detection system to spectrally separate the Doppler broadened Rayleigh-Brillouin (molecular) scattering and the much less Doppler broadened Mie (aerosol) scattering, thus allowing the spectral lineshape of the molecular scattering to be determined. A total scattering channel that includes both the Mie and Rayleigh-Brillouin scattering is also measured to determine aerosol backscatter ratio simultaneously. Ideally the inversion method requires a pressure at one altitude as the only necessary independent input, along with the assumption of local thermal and hydrostatic equilibrium, and the ideal gas law. For the present HSRL system, a reference temperature at one altitude and time is used to determine a constant normalization factor needed for accurate temperature profiles. This reference temperature is obtained from local balloon soundings for the results presented.; This dissertation describes the iodine vapor filters, the laser transmitter, and the receiver setups and characteristics of the HSRL. The system uses an injection seeded pulsed Nd:YAG laser that is continuously tunable over frequency ranges of 12 GHz and is narrowband, 74 MHz FWHM. The pulsed laser can be locked to an absolute frequency using Doppler-free saturated absorption spectroscopy. The iodine filters are temperature controlled and provide greater than 39 dB rejection of the aerosol backscatter signal with sensitivity in the measured signal to air temperature of 0.4%/K.; A unique feature of the system is the use of a relatively modest size transmitter and receiver system, yet it provides temperature profiles over a range of 500 m up to 15 km, with photon counting errors contributing less than 1 K and an estimated measurement precision of 1.9 K at 1 km. With the lidar data normalized using a reference temperature at one altitude and time from a local balloon sounding, the HSRL has demonstrated RMS deviations in the temperature measurements from the balloon soundings of 1.5 to 2.0 K over an altitude range of 2–5 km for one hour and 300 m averaged temperature profiles. The temperature uncertainty in the lidar measurements is mostly attributed to a 0.7% RMS variation in the photomultiplier tubes and is not an intrinsic source of error in the lidar system. The data presented are compared to local balloon data and show that the lapse rates, tropopause altitudes, and temperature inversions are in good agreement. Several nights of data are presented to demonstrate the salient features of this lidar system and to assess the accuracy of the measurements.
机译：本文提出了一种高光谱分辨率激光雷达（HSRL），可同时测量大气温度，压力，气溶胶与分子的后向散射比以及气溶胶消光系数的垂直分布。激光雷达使用在532 nm处操作的窄带脉冲激光源，碘蒸气滤光片用作检测系统中的窄带陷波滤光片，以光谱分离多普勒增宽的瑞利-布里渊（分子）散射和少得多的多普勒增宽的Mie（气溶胶）散射，因此可以确定分子散射的光谱线形。还测量了同时包括Mie和Rayleigh-Brillouin散射的总散射通道，以同时确定气溶胶的反向散射比。理想情况下，反演方法需要一个高度上的压力作为唯一必要的独立输入，并假定局部热和静水平衡，以及理想的气体定律。对于当前的HSRL系统，使用一个高度和时间的参考温度来确定精确温度曲线所需的恒定归一化因子。该参考温度是从当地气球测得的结果中得出的。本文介绍了碘蒸气过滤器，激光发射器以及HSRL的接收器设置和特性。该系统使用注入籽晶脉冲Nd：YAG激光器，该激光器在12 GHz频率范围内连续可调，窄带74 MHz FWHM。使用无多普勒饱和吸收光谱仪可以将脉冲激光锁定到绝对频率。碘过滤器是受温度控制的，可对气溶胶反向散射信号提供大于39 dB的抑制，被测信号对空气温度的敏感度为0.4％/ K。该系统的独特功能是使用了相对适中的发射器和接收器系统，但它提供了500 m至15 km范围内的温度分布，光子计数误差贡献不到1 K，估计的测量精度为1公里处1.9K。通过使用在一个高度和时间从本地气球测深仪处的参考温度对激光雷达数据进行归一化，HSRL证明了在一个2-5 km的高度范围内，温度测量值在1.5至2.0 K的气球测深仪中的RMS偏差小时的平均气温为300 m。激光雷达测量中的温度不确定性主要归因于光电倍​​增管中0.7％RMS的变化，而不是激光雷达系统中的固有误差源。所提供的数据与当地的气球数据进行了比较，并显示出流失率，对流层顶高度和温度反转非常吻合。呈现了数晚的数据，以证明该激光雷达系统的显着特征并评估测量的准确性。

著录项

  • 作者

    Hair, Johnathan Wayne.;

  • 作者单位

    Colorado State University.;

  • 授予单位 Colorado State University.;
  • 学科 Physics Atmospheric Science.; Physics Optics.; Remote Sensing.
  • 学位 Ph.D.
  • 年度 1998
  • 页码 165 p.
  • 总页数 165
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 大气科学（气象学）;光学;遥感技术;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号