Source localisation on aircraft in flight - new measurements with the DLR research aircraft Airbus 320 ATRA

Abstract

Fly-over measurements with a large microphone array were performed with the Airbus A320-232 research aircraft ATRA of DLR. A large multi-arm spiral array was set up on the end of the runway of the airport. The aircraft trajectory was estimated from the vertical distance and time delays measured with an array of vertically mounted laser distance meters and GNSS trajectories recorded on board of the aircraft. Source localisation maps were obtained from a hybrid deconvolution method. The source powers in different regions of the aircraft were calculated by integrating over the source regions. The total power in the whole interrogation area matches the power in the far-field spectra, apart from contributions from sources on the ground plane which are reduced by focusing the array on the aircraft. Results from fly-overs in the same or in different configurations can be compared on the basis of the integration results and the individual sources can be ranked according to their contribution to the overall sound pressure.