Calibration and Improved Speckle Statistics of IM-CW Lidar for Atmospheric CO2 Measurements
Calibration and Improved Speckle Statistics of IM-CW Lidar for Atmospheric CO2 Measurements
复制标题
用于大气 CO2 测量的 IM-CW 激光雷达的校准和改进的散斑统计
DOI：
10.3390/atmos11070737
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发表时间：
2020-07
期刊：
影响因子：
2.9
通讯作者：
Guanglie Hong
中科院分区：
文献类型：
--
作者：
Xindong Liang;Hao Liu;Tao Chen;Wei Kong;Guanglie Hong
研制了一种用于大气CO2测量的强度调制连续波（IM-CW）积分路径差分吸收（IPDA）光纤激光雷达。在提高测量精度方面，有两个主要的挑战在以前的研究中没有得到足够的重视：一是光学元件的温度敏感性，由于元件特性的漂移而导致的偏差;二是散斑噪声恶化的信噪比。通过热控制组件，实现了0.003 dB的目标校准精度，对应于1 km路径上优于1 ppm的CO2浓度精度。移动漫射器可以通过时间平均来减少散斑噪声。在本文中，通过使用安装在光学天线上的振动电机，由发射的激光束的扰动代替漫射器的移动。选择具有小波长间隔的开和关波长可以改善两个激光散斑场之间的相关性。这些改进导致IPDA激光雷达系统的精度提高。最后，分析了改进后的激光雷达性能。利用地形靶标模拟了大气CO2浓度的日变化，结果与现场传感器测量的数据吻合较好。IPDA激光雷达和原位传感器之间的偏差的均方根（rms）小于1.4%。
An intensity modulated, continuous-wave (IM-CW) integrated path differential absorption (IPDA) fiber-based lidar is developed herein for measuring atmospheric carbon dioxide (CO2). There are two main challenges in improving measurement accuracy, which have not been given enough attention in the previous research: one is that temperature sensitivity in optical components causes biases, due to the drift of component characteristic, and the other is that speckle noise deteriorates the signal-to-noise ratio. With the components thermally controlled, a target calibration accuracy of 0.003 dB is realized, corresponding to a CO2 concentration precision of better than 1 ppm for a 1 km path. A moving diffuser can reduce speckle noise by time averaging. In this paper, movement of the diffuser is substituted by the perturbation of the emitted laser beam by using a vibrating motor mounted on the optical antenna. Selecting on and off wavelengths with a small wavelength separation can improve the correlation between two laser speckle fields. These improvements result in the improved accuracy of the IPDA lidar system. Finally, the lidar performance was analyzed after the improvements described above were implemented. The diurnal variations of the atmospheric CO2 concentration using a topographic target were performed, and the results showed good agreement with the data measured by an in situ sensor. The root mean square (rms) of the deviation between the IPDA lidar and the in situ sensor was less than 1.4%.
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影响因子：
1.6
作者：
I. Freund
通讯作者：
I. Freund
影响因子：
5
作者：
Abshire, James B.;Ramanathan, Anand;Browell, Edward V.
通讯作者：
Browell, Edward V.
DOI：
--
发表时间：
2001
期刊：
--
影响因子：
--
作者：
J. Sathaye;S. Schneider;T. Stocker;B. Robinson;R. Scholes;G. Richels;R. Pachauri;B. Pittock
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影响因子：
1.9
作者：
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通讯作者：
S. Kameyama;M. Imaki;Y. Hirano;S. Ueno;S. Kawakami;D. Sakaizawa;T. Kimura;M. Nakajima
影响因子：
1.9
作者：
Gibert, Fabien;Pellegrino, Jessica;Di Nepi, Giorgia
通讯作者：
Di Nepi, Giorgia