A Decentralized but Synchronous Multi-ChannelMeasuring System for Aircraft Noise Recording

摘要

The field of aero-acoustics is gaining increasingly in importance. One area ofthis field is concerned with the audible behavior of airplanes during take-off, fly-by and landing.This not only is a question of recording the noises, but also of identifying the mechanismsby which they are produced and their effects at ground level. Both the increasing level ofaircraft traffic and the increasing environmental awareness of the population are triggeringsuch investigations, the goal of which is to minimize both the noise generated by the aircraftthrough technical improvements and the impact of this noise on local residents through acousticoptimization of flight paths.In order to capture such aircraft noise over a wide area under field conditions with a minimumof effort, a measuring system with 60 microphones and a master station has been designed andimplemented. The core requirements placed upon this system are high degrees of mobility andflexibility, excellent data integrity and solid construction.These requirements precluded cabled connections between the individual measurement points.For all microphones, the master station is required to provide a real-time display of their soundlevels and third-octave spectra as well as to guarantee sample-synchronous sound recording. This high degree of data integrity together with the synchronous resolution of all measured values formed the most important preconditions for this project. Furthermore, the master station was also required for remote control and monitoring of each channel. A cost-effective solution was implemented based on 30 acoustic measuring instruments and modern network technologies.