Feasibility Study of Multi-Wavelength Differential Absorption LIDAR for CO2 Monitoring
AbstractTo obtain a better understanding of carbon cycle and accurate climate prediction models, highly accurate and temporal resolution observation of atmospheric CO2 is necessary. Differential absorption LIDAR (DIAL) remote sensing is a promising technology to detect atmospheric CO2. However, the traditional DIAL system is the dual-wavelength DIAL (DW-DIAL), which has strict requirements for wavelength accuracy and stability. Moreover, for on-line and off-line wavelengths, the system’s optical efficiency and the change of atmospheric parameters are assumed to be the same in the DW-DIAL system. This assumption inevitably produces measurement errors, especially under rapid aerosol changes. In this study, a multi-wavelength DIAL (MW-DIAL) is proposed to map atmospheric CO2 concentration. The MW-DIAL conducts inversion with one on-line and multiple off-line wavelengths. Multiple concentrations of CO2 are then obtained through difference processing between the single on-line and each of the off-line wavelengths. In addition, the least square method is adopted to optimize inversion results. Consequently, the inversion concentration of CO2 in the MW-DIAL system is found to be the weighted average of the multiple concentrations. Simulation analysis and laboratory experiments were conducted to evaluate the inversion precision of MW-DIAL. For comparison, traditional DW-DIAL simulations were also conducted. Simulation analysis demonstrated that, given the drifting wavelengths of the laser, the detection accuracy of CO2 when using MW-DIAL is higher than that when using DW-DIAL, especially when the drift is large. A laboratory experiment was also performed to verify the simulation analysis. View Full-Text
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Xiang, C.; Ma, X.; Liang, A.; Han, G.; Gong, W.; Yan, F. Feasibility Study of Multi-Wavelength Differential Absorption LIDAR for CO2 Monitoring. Atmosphere 2016, 7, 89.
Xiang C, Ma X, Liang A, Han G, Gong W, Yan F. Feasibility Study of Multi-Wavelength Differential Absorption LIDAR for CO2 Monitoring. Atmosphere. 2016; 7(7):89.Chicago/Turabian Style
Xiang, Chengzhi; Ma, Xin; Liang, Ailin; Han, Ge; Gong, Wei; Yan, Fa. 2016. "Feasibility Study of Multi-Wavelength Differential Absorption LIDAR for CO2 Monitoring." Atmosphere 7, no. 7: 89.
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