# Commission Directive (EU) 2015/996 of 19 May 2015 establishing common noise assessment methods according to Directive 2002/49/EC of the European Parliament and of the Council (Text with EEA relevance), Division: Source directivity

Extent: E+W+S+N.I.

The horizontal directivity ΔLW,dir,hor,i in dB is given in the horizontal plane and by default can be assumed to be a dipole for rolling, impact (rail joints etc.), squeal, braking, fans and aerodynamic effects, given for each i-th frequency band by:
ΔLW,dir,hor,i = 10 × lg(0,01 + 0,99 · sin2 φ)
(2.3.15)
The vertical directivity ΔLW,dir,ver,i in dB is given in the vertical plane for source A (h = 1), as a function of the centre band frequency fc,i of each i-th frequency band, and for – π/2 < ψ < π/2 by:
ΔL W,dir,ver,i = 40 3 × 2 3 × sin 2 × ψ − sin ψ × lg f c,i + 600 200
(2.3.16)
For source B (h = 2) for the aerodynamic effect:
ΔLW,dir,ver,i = 10 × lg(cos2 ψ)
for ψ < 0
(2.3.17)
ΔLW,dir,ver,i = 0 elsewhere
Directivity ΔLdir,ver,i is not considered for source B (h = 2) for other effects, as omni-directionality is assumed for these sources in this position.

---
Source: https://www.legislation.gov.uk/eudr/2015/996/annex/division/ASSESSMENT/division/2/division/2.3/division/2.3.2/division/9 (the official version)
Page: https://openlegislation.uk/eu-directive-2015-996/annex/division-ASSESSMENT/division-2/division-2.3/division-2.3.2/division-9
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.