With weather patterns growing increasingly unstable, so does the need to alert the public to flood warnings. Added to that the potential threats posed by the War in Ukraine to Western Europe, and the German federal government and associated German states, decided to update their existing post-Cold War sirens. One local authority installed a new digital siren system that was funded by an 88 Mio EUR-backed funding program. Electronic sirens support power control with the option to change signal direction and manage speech transmissions. The responsibility for simulating how the sound from this new system propagates fell to ATDI’s flagship modelling tool, HTZ.
HTZ features a Sound coverage calculator which allows users to calculate the impact of different terrains, building density, signal strength, heights of emitters and the siren system configuration on sound propagation. These simulation results reflect the different heights of the emitting installation, power direction and minimum sound levels.
The Accellonet team set up siren locations as “stations” and used the signal direction as an antenna parameter. Predominantly, the omnidirectional signal propagation from a source point was applied as default. They incorporated a building layer using LOD2 data and a 1m grid clutter to model the coverage areas. The results identified that buildings were the main sound blockers with streets propagating the sound well. The results were exported to a GIS for presentation along with the site parameters for planning.
This project is the first of many planned across Germany. The 88 Mio EUR funding program will finance the replacement systems for up to 16 local authorities. Lessons learned from the installation of this first system provide a strong foundation for future rollouts.
Accellonet proposes to improve integration by using geographical information systems such as ArcGIS and with the aid of scripting speed up calculations.