Coherent 2 μm differential absorption and wind lidar with conductively cooled laser and two-axis scanning device

A coherent 2 μm differential absorption and wind lidar (Co2DiaWiL) was developed to measure CO2 concentration and line-of-sight wind speed. We conductively cooled a pumping laser head to −80°C and diode arrays to approximately 20°C. A Q-switched laser outputs an energy of 80 mJ (pulse width 150 ns (FWHM), pulse repetition frequency up to 30 Hz). CO2 measurements made over a column range (487-1986 m) for 5 min accumulation time pairs achieved 0.7% precision. Line-of-sight wind speeds for ranges up to approximately 20 km and returns from a mountainside located 24 km away from the Co2DiaWiL were obtained.