Author Affiliations
1School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China2Chinese Academy of Sciences Key Laboratory of Geospace Environment, Hefei 230026, China3Anhui Mengcheng Geophysics National Observation and Research Station, Bozhou 233527, China4Northwest Institute of Nuclear Technology of China, Xi’an 710024, Chinashow less
Fig. 1. Pure rotational Raman spectrum of N2 and O2
Fig. 2. (a) Ratio of rotational Raman echo signal intensities
; (b) Comparison of statistical temperature uncertainty between 532 nm and 354.8 nm Raman lidar systems
(a)转动拉曼回波信号强度之比
;(b) 532 nm和354.8 nm拉曼激光雷达系统温度不确定度的比较
Fig. 3. Light path diagram of the Raman lidar system
Fig. 4. Temperature sensitivity of pure rotational Raman signals
Fig. 5. Statistical temperature uncertainty versus filter center wavelength for different filter bandwidth in the daytime. (a) Δλ1=Δλ2=0.1 nm; (b) Δλ1=Δλ2=0.3 nm; (c) Δλ1=0.3 nm, Δλ2=0.5 nm; (d) Δλ1=0.3 nm, Δλ2=0.8 nm
Fig. 6. Statistical temperature uncertainty versus filter center wavelengths. (a), (b) Contour map of the variation of the statistical temperature uncertainty in daytime and nighttime detection with central wavelength CWL1 and CWL2; (c), (d) CWL1 takes a fixed value, the statistical temperature uncertainty changes with CWL2 in daytime and nighttime; (e), (f) CWL2 takes a fixed value, the statistical temperature uncertainty changes with CWL1 in daytime and nighttime
Fig. 7. Contour map of statistical temperature uncertainty varying with optical density
Fig. 8. (a) Statistical temperature uncertainty; (b) Statistical error of water vapor mixing ratio in the daytime
Parameter | Value | Temporal resolution/s | 1200 | Spatial resolution/m | 105 | Emission optical efficiency | 0.8 | Quantum efficiency of PMT | 0.25 | Overlap function | 1 |
|
Table 1. Simulation parameters of Raman lidar system
Device | Parameter | Value | Laser | Wavelength/nm | 354.8 | Repetition rate/Hz | 50 | Pulse energy/mJ | 200 | Divergence angle/mrad | <0.5 | Beam expander | Beam-expansion factor | 10 | Telescope | Diameter/mm | 400 | Field of view/mrad | 0.05 |
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Table 2. Key parameters of Raman lidar system
Δλ1/nm
| Δλ2/nm
| ΔT/K
| 0.1 | 0.1 | 5.35 | 0.3 | 0.3 | 3.11 | 0.3 | 0.5 | 2.63 | 0.3 | 0.8 | 2.36 |
|
Table 3. Average value of statistical temperature uncertainty
| IF0 | IF1a/IF1b | IF2 | IF3 | IF4 | Center wavelength/nm | 355 | 354.15 | 353.3 | 407.7 | 386.8 | Band width/nm | 8.5 | 0.3 | 0.5 | 0.3 | 0.5 | Peak transmission | 0.56 | 0.59 | 0.52 | 0.75 | 0.7 | Optical density | 5 | 3 | 6 | 7 | 7 |
|
Table 4. Parameters of interference filter