Reference:R&D Report 9842 Title:The UK Civil Aircraft Noise Contour Model ANCON - Improvements in Version 2 Description:Version 1 of the UK aircraft noise contour model (ANCON-1) is described in DORA Report 9120. This supplementary report describes changes that have been made to upgrade the model to ‘Version 2’ standard (ANCON-2). Until a planned self-contained replacement for DORA Report 9120 is released, the two reports together provide an interim technical description of the ANCON-2 noise model as of June 1999.
The process by which ANCON-2 calculates noise exposure is, for the most part, the same as that of ANCON-1. The main change is that the contribution to Sound Exposure Level from an aircraft flight segment is now derived from Noise-Power-Distance tables as a function of engine thrust rather than from wholly empirical Reference Noise Levels (RNLs).
The first edition of the updated ANCON-2 model (‘ANCON-2.1’), used to produce the 1996 and 1997 Leq contours for the London airports, is described briefly in an appendix; however, like its predecessor, ANCON-2 will be subject to continuing development as the DORA database expands and internationally agreed modelling procedures are improved.