18 January 2011
The Environmental Research and Consultancy Department (ERCD) of the Civil Aviation Authority (CAA) has produced its annual report on noise exposure contours at Heathrow, Gatwick and Stansted for 2009. This is a detailed report that includes scale diagrams of noise exposure contours providing an overall impression of their proximity to major towns.
The magnitude and extent of the aircraft noise around these airports are depicted on maps by contours of constant aircraft noise index (Leq) values. The contours are generated by a computer model validated with noise measurements, which calculates the emissions and propagation of noise from arriving and departing air traffic.
http://www.dft.gov.uk/pgr/aviation/environmentalissues/nec/secnoise09/