To make accurate forecasts, meteorologists need data on the vertical distribution of temperature and humidity in the atmosphere. The LIDAR system developed by EPFL can collect these data continuously and automatically up to an altitude of 10km. On August 26, EPFL will officially transfer this custom-developed LIDAR to MeteoSwiss, and from this point on Swiss forecasters will have access to this source of vertical humidity data for the models they use to calculate weather predictions. The project was supported by funding from the Swiss National Science Foundation.
The LIDAR system developed by EPFL is a relative of the familiar RADAR systems used widely in weather forecasting. Instead of sending radio waves out looking for water droplets, however, the LIDAR sends a beam of light vertically into the sky. The "echo" here is a reflection of that light from different layers in the atmosphere. This reflection is used to build an instantaneous vertical profile of temperature and humidity….
Image of the new LIDAR system from the EPFL's website