Reflection on curved surfaces in a 2.5D ray-tracing method for electromagnetic waves exposure prediction in urban areas

Asymptotic methods are commonly used to predict exposure to electromagnetic waves in large environments such as urban areas. Specifically 2D beam-tracing is a very efficient solution in case of GIS 2.5D environments. Nevertheless taking into account reflection on curved vertical walls or curved ground in such methods is not straightforward. Indeed curved surfaces are mostly described as meshes and lead to artificial shadowing and inaccurate electric field estimation. We explain here how to avoid such problems without modifying existing geometry by using normal interpolation in a generalized beam-tracing technique, and present results for some real cases.