Analysis of the data collected so far can be viewed by adding the Overlay "dB(A)MAX Noise Contours.... Landings on Northern Runway Only" to the map.
As the title suggests only observations of aircraft landing on the northern runway were used in the creation of the contours, at the moment there is not
enough data to create a similar contours for the southern runway - when there is these will be added to the map.
Even though the iPhone has been calibrated against a profession grade Sound Level Meter the accuracy of the contours can not be
guaranteed and should therefore be treated as illustrative rather than definitive.
How to add the Overlay to the map:
How to interpret the contours:
dB(A) indicates the A weighted maximum sound level caused by the over flight of an aircraft. The value of dB(A) max was obtained for individual AudioBoo recordings that were then analysed using specialist (GIS) computer software. dB(A)Max does not take into account the duration or number of noise events so does not represent any measure of exposure to noise. The sample size is relatively small and in some areas observations, that are required to create the contours, are totally absent. The lack of observations directly north of the airport means that the contours, incorrectly, interpret these area to have similarly high dB(A)Max noise levels as experienced east of the runway - where there are measurements.
By all means please view the Contours Overlay together with the AudioMarkers (just tick both boxes), however, please remember that it is only the AudioBoo samples associated with aircraft landing on the northern runway that where used in their creation and currently there is no way of telling which these are - I am working on it!
Further information will be added in due course - in the mean time drop me an email should you have any questions
|Thanks to the services of...
|Defra: Airport noise maps
|GISc at Birkbeck
|CAA: Environmental Issues
|Apple App Store
|BAA Heathrow: Noise