Progresses in remote sensing of the atmosphere using the Udar (Light detection and
ranging) technique closely follows progresses in Laser technology. We developed a
mobile DIAL (differential absorption Lidar) system, based on high repetition rate
Excimerpumped dye lasers, for performing 2D and 3D-mappings of concentration
of NO, N02, S02, and 03. The high sensitivity of the system has been used for
numerous environmental studies and measurement campaigns, providing for the
first time a direct correlation between emission and immission.
Attractive results have been obtained under urban conditions, because of the
presence of strong concentration gradients, and fast fluctuations due to traffic. A
comparative study between Lyon, Stuttgart, Geneva and Berlin will be presented. In
particular, the Berlin-campaign demonstrates the possibility of detecting unknown
emitters and monitoring exportation-importation processes of atmospheric
pollution. A new stationary DIAL system has been recently constructed and
implemented on the top of a building in the center of the city Leipzig. It will
routinely perform concentration mappings of nitrogen oxides, sulfur dioxide and
ozone, giving access to long term evolution of pollution distributions.