The talk will present the design and measurement results from two Raman lidars for simultaneous water vapor, temperature and aerosol observations, recently developed at the Swiss Federal Institute of Technology –Lausanne (EPFL). In both lidars, the water vapor mixing ratio is derived from water vapor and nitrogen vibrational signals and the aerosol extinction and backscatter are measured using pure-rotational Raman and elastic signals.

The first lidar is an fully automated, water vapor /aerosol lidar developed for operational use in MeteoSiss. The lidar supplies water vapor mixing ratio and aerosol extinction and backscattered coefficients at 355 nm. The operational range of the lidar is 100-7000 m (night time) and 100- 5000 m (daytime) with time resolution of 30 min. The spatial resolution varies with height from 25 to 300 m in order to maintain the maximum measurement error of 10%. The system is designed to provide long-term database with minimal instrument-induced variations in time of the measured parameters. The lidar is in a test phase in the main aerological station of Meteoswiss- Payerne and will be operational from September 2008. Upgrade with a temperature channel is ongoing and it will be operational in 2010.

The second lidar is a new generation solar-blind system with an operational range 10-500 m and high spatial (1.5 m) and temporal (1 s) resolutions for simultaneous humidity, temperature, and aerosol measurements in the lower atmosphere. To maintain the measurement accuracy while operating with fixed spatial and temporal resolution, the receiver is designed to provide lower than 10 dynamic range of the signals within the operational range of the lidar. The lidar has 360° azimuth and 240° scanning ability and can be operated in an automated mode. The lidar is used to study the structure of the lower atmosphere over complex terrains and in particular to advance our understanding of turbulent blending mechanisms in the unstable atmosphere.