Method for Retrieving Pollution Gas Concentration from Raman Lidar Return
HONG Guang-lie1, ZHANG Yin-chao2, ZHOU Meng-ran1, CAO Kai-fa2, ZHOU Jun2
1. Graduate School of Chinese Academy of Sciences, Beijing 100039, China 2. Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
Abstract：Raman lidar is an important tool for the detection of atmosphere pollution, and inversion for lidar returns is an important process. The key for inversion is to get transmission exponential function exp∫R0[α(λ1,z)-α(λ2,z)]. Three methods with extinction coefficient as the center are presented. First, 532 nm atmospheric extinction coefficient was used to indirectly obtain α(λ1,z) and α(λ2,z), This method has been used generally by people. Two new methods were proposed: 1, reference gas with approximate Raman wavelength is used so that α(λ1,z)＝α(λ2,z). 2, Mie-Rayleigh scattered return with wavelength λ1 or λ2 is used to compute exp∫R0[α(λ1,z)-α(λ2,z)].
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