An analytic model for acoustic scattering from an impedance cylinder placed normal to an impedance plane

Abstract

An analytic model for the scattering of a spherical wave off an infinite right cylinder embedded perpendicularly in a ground surface is developed in cylindrical coordinates. The model is developed to simulate a single tree and is developed as a first piece to creating a model for estimating attenuation in a forest based on scattering from individual tree trunks. Comparisons are made to the plane wave case, the transparent cylinder case, the transparent ground case, and the rigid ground case as a method of theoretically verifying the model. Agreement is excellent for all benchmark cases. Model sensitivity to five parameters is determined, which aids in error analysis, particularly when comparing the model results to experimental data, and offers insight into the inner workings of the model. An experiment was performed to collect real-world data on scattering from a cylinder normal to a ground surface. The data from the experiment is analyzed with a transfer function method into frequency and impulse responses. The model results are compared to the experimental data. Agreement is good below 1500 Hz, and poor for higher frequencies.