Noise is one of the most important environmental problems in the vicinity of traffic installations such as airports, roads and railway lines. Traffic noise originates from propulsion, wheels and air flow and is emitted into the atmosphere. The propagation of sound waves in the atmosphere is largely determined by refraction, absorption and scattering depending on the actual state of the atmosphere. Reflections and diffractions at the topography (vegetation, buildings, hills etc.) cause further modifications. Since the topography again influences the atmosphere, the complete system of atmosphere, topography and sound field has to be considered.
At the DLR Institut für Physik der Atmosphäre simulation models are developed that describe the system of atmosphere, topography and sound waves in a consistent manner. Such models are the basis of more simplified noise prediction tools. These tools can be used, for example, to define low-noise approach and departure routes at airports depending on the actual weather type and taking advantage from the natural damping properties of the atmosphere and the ground. Further applications are the planning of low-noise traffic lines as well as other noise reducing measures (e.g. noise barriers).
Our research activities are embedded in the DLR-projects "VEU" (traffic development and environment) and "flexiGuide" (flexible air traffic management to protect the environment).