Showing papers by "Robert T. Shin published in 1997"

A method of moments model for VHF propagation

Abstract: Predictions of a numerical model for site specific very high frequency (VHF) propagation over irregular terrain are compared to experimental data and to other propagation models. The numerical model is based on an iterative version of the method of moments (MOM) known as the banded matrix flat surface iterative approach (BMFSIA) for either perfectly conducting or penetrable surfaces rough in one direction only. Due to the large size of the numerical problem (65000 to 130000 unknowns), a parallel implementation of the method is presented and applied in the simulations. Comparisons with measurement data show good agreement overall and also illustrate the sensitivity of the model to input terrain profiles. Comparisons with other propagation models show good agreement also in cases where these models are expected to be valid and further clarify the limitations of the approximations made in these methods.