A Raman Lidar system to measure water vapor and temperature in the atmospheric boundary Layer

A new generation high resolution Raman lidar has been developed at the Swiss Federal Institute of Technology at Lausanne (EPFL) to measure at unprecedented resolution water vapor and temperature profiles simultaneously in the atmospheric boundary layer (ABL). This system operates in the solar blind spectral region and comprises a high energy high repetition rate fourth harmonic Nd:YAG laser, a multi-mirror multiple field of view telescope system, a high throughput prism based water vapor polychromator, and a double grating temperature polychromator. The high dynamic range is based on 4 mirror system which permits measurements up to 500 m with a near constant signal to noise ratio. Temperature and water vapor are measured in the ABL with constant signal to noise at 1.5 m and 1 second resolution. System description details and calibration procedures are described in this presentation. First applications include high resolution observations of the diurnal cycle of the atmospheric boundary layer evolution near the earth's surface, including day and night time transitions.