探测低空大气CO2浓度的同时可以探测大气风场。采用相干探测较非相干探测具有更高的信噪比, 而目前1.5 μm波长由于在人眼安全、系统设计简单廉价等方面存在一定优势, 使1.5 μm可能成为未来探测气溶胶激光雷达的主流波长。本文阐述了激光雷达相干探测大气CO2与风场的原理, 设计了1.5 μm相干探测激光雷达系统, 并对系统的信噪比进行了估算, 得出结论: 1.5 μm相干探测风场与CO2是可行的, 经过3分钟的脉冲积累, 在3km处仍具有高于10的信噪比值。

Concentration of CO2 and wind field in low altitude can be measured by coherent lidar simultaneously, with better signal-to-noise ratio (SNR) than incoherent detection. At present the 1.5 microns laser is both eye-safe and low-cost for building a lidar system . The 1.5 microns wavelength will also be the best candidate for the future aerosol lidar. In this paper, the principles of detecting concentration of CO2 and wind field with coherent lidar are described and the design details of coherent lidar with 1.5 microns are given. From the simulated SNR, it can be concluded that heterodyne detection of wind field and concentration of CO2 with 1.5 microns is feasible and the estimated SNR at 3km distance in daylight can be better than 10 for 3 minutes integraton.