A general approach for extending the range of application of standard noise mapping methods

Abstract

International audienceStandard noise mapping software implements standard prediction methods. Such methods are often unable to predict the effects of complex or innovative noise reduction measures, and therefore unsuitable for local planning and impact studies. On the other hand, advanced prediction schemes are considered too slow for practical use in noise mapping. In this paper we will present a new approach combining standard engineering noise prediction schemes with user-defined extensions. Extensions are used to predict level differences and/or additional insertion losses for the complex devices as compared to standard devices supported by the standards. The insertion losses can be estimated from experimental data, from analytical considerations or by means of numerical simulations. This approach can be used to implement such features as: barriers with cantilever, trenches with partial covering, interaction between train body and nearby barriers, reflections from complex walls, diffraction by screen tops, low barriers near traffic lanes, belts of trees with specific planting schemes, ground roughness elements Extensions are implemented as independent software modules and therefore do not interfere with the standard methods. Disabling extensions allows calculation of noise maps according to legal requirements, enabling extensions allows assessment of noise levels at the local level, including the effects of innovative mitigations