Unmanned aerial systems (UAS), commonly referred to as drones, are being deployed in an increasing number of applications, including delivery, inspection, mapping and surveillance. Beyond the single-aircraft operations established today, current developments point towards the swarm concept, in which several UAS operate in coordinated formation. Such formations offer gains in efficiency and a reduction in logistical effort, but they also raise concerns regarding noise, particularly in urban environments. The acceptance and deployment of drone swarms may therefore depend on how they sound \u2014 a question that has to be addressed in advance if the technology is to be environmentally compatible. Acoustic simulation and auralization methods developed at IHTA make such an assessment possible: rather than describing predicted noise as a value on a noise map, the virtual swarm is auralized. Swarm formation, routing and operating conditions can thus be varied systematically, and the resulting perceptual consequences, in particular the annoyance experienced by listeners, quantified in listening experiments that can inform early-stage planning and the regulation of swarm deployment and routing.<\/p>\n
A swarm flyover in an urban environment places substantial demands on the simulation: higher-order reflections between building facades, diffraction, multiple moving sources with direction-dependent radiation, and propagation through an inhomogeneous medium must all be accounted for simultaneously. The simulation workflow therefore has to be verified against measured data.<\/p>\n\n\t\t