Feasibility Study for Future Spaceborne Coherent Doppler Wind Lidar, Part 2: Measurement Simulation Algorithms and Retrieval Error Characterization
Feasibility Study for Future Spaceborne Coherent Doppler Wind Lidar, Part 2: Measurement Simulation Algorithms and Retrieval Error Characterization
复制标题
DOI：
10.2151/jmsj.2017-018
复制
发表时间：
2017-06
影响因子：
3.1
通讯作者：
P. Baron;S. Ishii;K. Okamoto;Kyoka Gamo;K. Mizutani;C. Takahashi;T. Itabe;T. Iwasaki;T. Kubota;T. Maki;R. Oki;S. Ochiai;D. Sakaizawa;M. Satoh;Yohei Satoh;T. Tanaka;M. Yasui
中科院分区：
文献类型：
--
作者：
P. Baron;S. Ishii;K. Okamoto;Kyoka Gamo;K. Mizutani;C. Takahashi;T. Itabe;T. Iwasaki;T. Kubota;T. Maki;R. Oki;S. Ochiai;D. Sakaizawa;M. Satoh;Yohei Satoh;T. Tanaka;M. Yasui
日本正在进行一项利用搭载在超低空卫星上的相干多普勒激光雷达测量对流层风的可行性研究。所考虑的激光雷达使用3.75W的2.05微米激光光源。为了评估测量性能，进行了风测量的模拟。任务定义在配套文件(第1部分)中给出，而在本文中，我们描述了测量模拟器，并对反演的视线(LOS)风的误差进行了表征。风场是由噪声后向散射信号的多普勒频移反演出的，沿轨道的水平分辨率为100公里，垂直分辨率在0.5至2公里之间。云场和风场是观测系统模拟实验的伪真值，而气溶胶数据来自Model-of-Aerosol-Species-IN-the-Global-AtmospheRe(MASINGAR)，受伪真值风的约束。本文给出了一颗近极轨道卫星和35°天底角的夏季整整一个月资料的分析结果。在距地面8公里以下，反演优良率为30-55%，中位数LOS风误差优于0.6m S−1(水平风为1.04m S−1)。在对流层上层，这一比例在南半球和高纬度地区不到15%。然而，在北热带和中纬度地区，这一比例仍然是35%，那里经常出现冰云。不同纬度的对流层中值视风测量误差为1~2m S−1(水平风为1.74m~3.5m S−1)。这些误差主要是由空间大气不均匀引起的不确定因素造成的。
A feasibility study of tropospheric wind measurements using a coherent Doppler lidar aboard a super low altitude satellite is being conducted in Japan. The considered lidar uses a 2.05 µm laser light source of 3.75 W. In order to assess the measurement performances, simulations of wind measurements were conducted. The mission definition is presented in a companion paper (Part 1) while, in this paper, we describe the measurement simulator and characterize the errors on the retrieved line-of-sight (LOS) winds. Winds are retrieved from the Doppler-shift of the noisy backscattered signal with a horizontal resolution of 100 km along the orbit track and a vertical resolution between 0.5 and 2 km. Cloud and wind fields are the pseudo-truth of an Observing System Simulation Experiment while aerosol data are from the Model-of-Aerosol-Species-IN-the-Global-AtmospheRe (MASINGAR) constrained with the pseudo-truth wind. We present the results of the analysis of a full month of data in summer time for a near-polar orbiting satellite and a LOS nadir angle of 35°. Below » 8 km, the ratio of good retrievals is 30 – 55 % and the median LOS wind error is better than 0.6 m s −1 (1.04 m s −1 for the horizontal wind). In the upper troposphere, the ratio is less than 15 % in the southern hemisphere and high-latitudes. However, the ratio is still 35 % in the northern Tropics and mid-latitudes where ice-clouds frequently occur. The upper-tropospheric median LOS-wind measurement error is between 1 – 2 m s −1 depending on the latitude (1.74 – 3.5 m s −1 for the horizontal wind). These errors are dominated by uncertainties induced by spatial atmospheric inhomogeneities.