Modeling RF and acoustic signal propagation in complex environments

A computational framework is described for modeling acoustic and radio-frequency (RF) signal propagation in complex environments, such as urban, mountainous, and forested terrain. In such environments, the influences of three-dimensional atmospheric fields and terrain variations must be addressed. The approach described here involves creation of a full environmental data representation (abstraction layer), which can be initialized with many different environmental data resources, including weather forecasts, digital terrain elevations, landcover types, and soil properties. The environmental representation is then converted into the parameters needed for particular signal modalities and classes of propagation algorithms. In this manner, execution of the signal propagation calculations is isolated from the sources of environmental data, so that all models will function with all types of environmental data. The formulation of the acoustic (infrasound and audible) and RF (VHF/UHF/SHF) feature spaces is also described. Example calculations involving infrasound propagation with 3D weather fields and RF propagation in mountainous terrain are provided.