Noise levels from low flying military jet aircraft in the UK are controlled by restrictions placed upon the height and speed at which particular types of aircraft are allowed to fly. This ensures that, on the ground, disturbance and annoyance are minimised and noise levels are kept below those accepted for occupational health effects even though people may be subjected to noise from several aircraft or several overpasses in any one day. The aircraft are authorised to fly at low level in any unrestricted airspace outside civilian and military air traffic control zones but certain locations are excluded such as major built up areas and large industrial sites. This wide access to airspace minimises the number of times particular properties are overflown. As part of an ongoing scientific evaluation noise signature measurements of low level overflights have been made to establish the effect of shielding, reflections and reverberant build up in the spaces within groups of buildings. This paper describes the project and considers the results in the form of changes to the signature waveshapes and the resultant effect on the metrics in current use to describe this type of noise in the community.
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