Simulation of Satellite Water Vapour Lidar Measurements: Performance Assessment under Real Atmospheric Conditions.
Simulation of Satellite Water Vapour Lidar Measurements: Performance Assessment under Real Atmospheric Conditions.
复制标题
卫星水蒸气激光雷达测量模拟：真实大气条件下的性能评估。
DOI：
10.1016/j.rse.2007.08.008
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发表时间：
2008
影响因子：
13.5
通讯作者：
G. Ehret
中科院分区：
文献类型：
--
作者：
P. Girolamo;A. Behrendt;C. Kiemle;V. Wulfmeyer;H. Bauer;D. Summa;A. Dörnbrack;G. Ehret
利用激光雷达模拟器对卫星水汽差分吸收激光雷达（DIAL）系统的性能进行了评估。2002年5月15日，在欧空局的水汽激光雷达实验期间，利用机载德国航空航天中心（德国航天中心）的水汽DIAL进行的测量，结合PSU/NCAR中尺度模式（MM 5）的输出，获得了高分辨率和高精度的后向散射和水汽场。这些数据和模型输出可作为模拟器的输入，以便评估卫星DIAL在高度不均匀大气条件下的性能，包括待评估的云层。空中测量显示平流层空气侵入对流层，在德国航天中心猎鹰飞机飞行高度以上使用的MM 5数据的特点是对流层上部湿度水平非常高，与从对流层到最低平流层的中纬度强输送事件有关。模拟器的结果表明，最大系统误差不超过5%，直到16公里，除了在厚卷云和中层云的存在下，光学厚度高达2，偶尔，在干燥的平流层入侵，而当采用世界气象组织（WMO）的空间测量分辨率时，直到16 km的随机误差小于20%。数值天气预报（NWP）的观测要求。如果考虑来自参考大气的干燥的对流层上部/平流层下部（UTLS）区域，则偏差甚至更小。结果证实了卫星水蒸气DIAL系统有能力检索对流层水蒸气和粒子后向散射场的薄结构，以及即使在有云的情况下也有能力提供低偏差和随机误差的测量。
A lidar simulator has been applied to assess the performances of a satellite water vapour differential absorption lidar (DIAL) system. Measurements performed by the airborne Deutsches Zentrum für Luft-und Raumfahrt (DLR) water vapour DIAL on 15 May 2002 during ESA's Water Vapour Lidar Experiment (WALEX), in combination with PSU/NCAR Mesoscale Model (MM5) output, were used to obtain backscatter and water vapour fields with high resolution and accuracy. These data and model output serve as input for the simulator, allowing for the performance of satellite DIAL under highly-inhomogeneous atmospheric conditions including clouds to be assessed. The airborne measurements show an intrusion of stratospheric air into the troposphere, and MM5 data used above the DLR Falcon airplane flight altitude are characterized by very high upper tropospheric humidity levels, comparable to those associated with strong mid-latitude transport events from the troposphere to the lowermost stratosphere. Results of the simulator reveal that the maximum systematic error does not exceed 5% up to 16 km, except in the presence of thick cirrus and mid level clouds with an optical thickness up to 2 and, occasionally, inside the dry stratospheric intrusion, while the random error is less than 20% up to 16 km when spatial measurement resolutions are applied that follow the World Meteorological Organization (WMO) threshold observational requirements for numerical weather prediction (NWP). The bias is even smaller if a drier upper troposphere/lower stratosphere (UTLS) region from a reference atmosphere is considered. The results confirm the capability of satellite water vapour DIAL systems to retrieve thin structures of the tropospheric water vapour and particle backscatter fields, as well as its capability to provide low bias and random error measurements even in the presence of clouds.