Influence analysis of the detection accuracy of atmosphere water vapor using the solar-blind ultraviolet Raman lidar

Abstract Solar-blind ultraviolet Raman lidar can realize the daytime detection of atmospheric water vapor, as the transmitting wavelength of 266.0 nm and its excited vibrational Raman spectra of N2, O2 and H2O are within the solar-blind region. However, the spectra of the O3, NO2, SO2 absorptions and fluorescence are within the solar-blind region as well, and Raman channel of H2O still has a small amount of residual solar background noise, which will influence the detection accuracy and detection capability of the solar-blind ultraviolet Raman lidar. Moreover, although a high efficiency polychromator is required to extract the vibrational Raman spectra of N2, O2 and H2O, the suppression of aerosol Mie scattering and molecular Rayleigh scattering, and optical cross-talks are still required to discuss carefully in detail. Simulation results show that the retrieval accuracy of water vapor mixing ratio using the solar-blind Raman lidar are mainly influenced by the O3 absorption and the optical cross-talk of aerosol Mie scattering and molecular Rayleigh scattering. The rejection ratio with more than 5 orders of magnitude to elastic scattering signal is required in the design of polychromator to avoid the optical cross-talk between each extracted spectrum. The influences of NO2, SO2 absorptions, solar background noise and fluorescence on the retrieval of water vapor mixing ratio can be neglected. The theoretical analysis of the solar-blind ultraviolet Raman lidar on the retrieval of water vapor mixing ratio can further enhance the performance of the system detection accuracy and detection capability.