RECORD 139 - Benchmark for Acoustic Source Localization of Flyover Microphone Array Measurements

The localization of acoustic sources of aircraft in flight is a core challenge for beamforming methods since they have first been used in the early 1990s independently by Bryce, Michel and Botcher. It has remained a field of active research, where different groups have applied similar methods to reconstruct the noise levels of aircraft components. However, the details of the methods themselves as well as their implementations may differ. Until now, no flyover microphone array dataset has been made broadly accessible to the research community. With this publication, we will make a data set available of a flyover recording of the DLR ATRA research aircraft, an Airbus 320-232. The recording was made in 2016 in the context of the Low Noise ATRA Project, which aimed to test noise reduction approaches. This particular recording was chosen because in this configuration, several aeroacoustic sources on the fuselage and airframe are present. The dataset contains the calibrated pressure signals from a large array of the DLR-Engine Acoustics Department with 231 microphones, arranged in logarithmic spirals. The arrangement is stretched in the direction of fligt, resulting in a diameter of 43 m along the longer, 36 meter on the shorter side. The aircraft velocity above ground was 88 m/s and the altitude was 180 m above the array. The dataset is provided in the HDF5-file format that is organized according to the structure used for the exchange of microphone array data in the past. Here, it is extended to accommodate the trajectory of the aircraft as well. Due to the movement of the aircraft and source region, data for the trajectory in the form of waypoints and reference times is provided. In this talk and publication, we will present the methods used by our research team andthe results we were able to accomplish with them.