Simplification of real-world terrain for outdoor acoustic propagation modeling

Approaches to outdoor sound propagation include models of attenuation for a set of standardized barriers and terrains. These various approaches take care to represent the physical nature of each barrier type. However selection of the appropriate barrier model for a real-world terrain segment is rarely presented. Complex logic is required to determine the appropriate barrier model to apply in the instances where the selection is addressed. This paper presents the Critical Point Analysis Terrain Simplification (CPATS), an algorithm for reducing the complexity of real-world terrain profiles. CPATS implements a finite differencing schema to determine critical points within the terrain segment. The results of this model are compared to a maximum deviation algorithm (MaxDev) of reducing terrain complexity. A statistical comparison between CPATS and MaxDev terrains is completed showing the superior capabilities of the CPATS model. The effect of the different simplified terrains is examined using the outdoor sound propagation code NORD2000. (C) 2016 Institute of Noise Control Engineering.