Use of a Model for Coherence Loss in the Context of Aircraft Fly-Over Measurements

Kurzfassung

Recent work on the auralisation of aircraft fly-overs has made it possible to accurately model the atmospheric loss of coherence during propagation based on the environmental conditions. This contribution discusses the impact of these models on acoustic source localisation results on the analysis of fly-over measurements with microphone arrays.We present a method that determines a modified point spread function (PSF), which takes the coherence loss into account. This modified PSF allows the optimisation of the array design and the calculation of shading factors, which so far have been based on design principles and experience. The aim is to generate robust localisation results for measurements under less than ideal environmental conditions.Furthermore, such a PSF can be applied in the hybrid deconvolution for moving sources, where it can significantly reduce the impact of the coherence loss on the source localisation results and the reconstruction of the source amplitudes. The capabilities and limits of this approach are demonstrated with synthetic test cases as well as microphone array measurements.