Airborne system for fast measurements of upwelling and downwelling spectral actinic flux densities.
Airborne system for fast measurements of upwelling and downwelling spectral actinic flux densities.
复制标题
用于快速测量上升流和下降流光谱光化通量密度的机载系统。
DOI：
10.1364/ao.44.000434
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发表时间：
2005
期刊：
影响因子：
1.9
通讯作者：
T. Trautmann
中科院分区：
文献类型：
--
作者：
E. Jäkel;M. Wendisch;Anke Kniffka;T. Trautmann
介绍了一种用于快速测量 305-700 nm 波长范围内光谱光化通量密度的机载系统。该系统称为光化通量密度计 (AFDM)。 AFDM 利用二极管阵列技术，分别测量下降流和上升流光谱光化通量密度，时间分辨率小于 1 s。对于机载测量，这意味着空间分辨率约为 60 m（假设飞机平均速度为 60 m/s）。因此，AFDM 可以解决光化辐射场的快速变化，这对于不均匀云或表面反射的条件特别重要。介绍了 AFDM 的实验室表征测量，并介绍了一种校正光学入口非理想角度响应的方法。此外，还显示了与光谱辐照度测量同时采样的示例现场数据。对光化通量密度测量光谱的水平变化进行了量化，并提出了阴天情况下的剖面测量。最后，讨论了云对光谱光化通量密度的影响。
An airborne system for fast measurements of spectral actinic flux densities in the wavelength range 305-700 nm is introduced. The system is called the Actinic Flux Density Meter (AFDM). The AFDM utilizes the diode array technique and measures downwelling and upwelling spectral actinic flux densities separately with a time resolution of less than 1 s. For airborne measurements this means a spatial resolution of approximately 60 m, assuming an average aircraft velocity of 60 m/s. Thus the AFDM resolves fast changes in the actinic radiation field, which are of special importance for conditions of inhomogeneous clouds or surface reflection. Laboratory characterization measurements of the AFDM are presented, and a method to correct the nonideal angular response of the optical inlets is introduced. Furthermore, exemplar field data sampled simultaneously with spectral irradiance measurements are shown. The horizontal variability of the measured spectra of actinic flux density is quantified, and profile measurements for overcast situations are presented. Finally, the effects of clouds on the spectral actinic flux density are discussed.