Study of the correction factors for aircraft noise façade measurements

Abstract Nowadays, society has the need for air transportation all around the world. The yearly increase in the number of passengers forces airports to operate to a maximum of their capacity. This leads to an augmentation of the fleet of each airline and consequently to an increase in aircraft noise emissions. Accordingly, procedures for measuring aircraft noise levels have been developed. There are international standards that specify how transport noise (aircraft, traffic and railroad) must be measured. ISO 1996-2 standard has an appendix called Annex B which specifies the reference position of the microphone to undertake the measurement, and simplified correction factors to use in case that the measurement must be located near a reflecting surface (3 dB) or directly over a reflecting surface (6 dB). A facade behaves like a reflecting surface and the correction factor to apply is relevant to the study of noise because with the reflections produced on the outside of a building, people nearby can be affected. Therefore, numerous studies verifying the correction factors of ISO 1996-2 Annex B have been performed on facades, particularly for traffic noise. Most of the findings from these studies demonstrate that features of the source-receiver geometry change the correction factor. However, this correction factor has not been tested yet for aircraft noise whose source-receiver geometry differs from that of traffic noise. This paper intends to test the correction factor for aircraft noise on facade. It also tries to determine which relationship can be found among the noise level at the reference position and features like the facade noise level, source-receiver geometry and flight type.