Statistics-based characterizations of acoustic propagation, namely, fading and coherence, are being developed as
functions of urban terrain zones. The fading and coherence curves are characterized for each of several urban terrain
zones of interest, and the resulting curves are parameterized as a function of frequency and distance from the source.
With the parameters for signal fading and coherence as a function of frequency, distance to source, and urban terrain
zone type, the decision support tool SPEBE (Sensor Performance Evaluator for Battle-space Environments) is extended
to urban areas. Combined with a separate effort characterizing background noise levels as functions also of
urban terrain zones, a tool for predicting probability of detection for various sources in urban areas is demonstrated.
Future US Army ground sensors in urban terrain will process acoustic signals to detect, classify, and locate sources of
interest. Optimal processing will require understanding of the effects of the urban infrastructure on sound propagation.
These include multi-path phenomena that must be accounted for in sensor placement and performance algorithms. This
work applies Fourier analysis to urban acoustic wave-field data from three-dimensional high-performance computations
to generate statistical measures of signal fading caused by scattering. The work calculates these measures from ratios of
Fourier transforms of wave-field signals with and without scattering to isolate the structure-induced scattering.