On time-domain numerical modeling of a ground losses in the problem of thin wire above an imperfect ground

The time domain numerical modeling of lossy ground effects in the analysis of thin wire above an imperfect ground is presented. Transient analysis via Galerkin-Bubnov Indirect Boundary Element Method (GB-IBEM) has proven to yield accurate and stable results for cases where a ground conductivity is approximated as a perfectly conducting (PEC) or pure dielectric medium. These approximations yield satisfactory accurate results for many practical scenarios, where variations in the ground conductivity do not significantly influence the transient response of the system. However, for configurations where such approximations are not satisfactory, for example if a wire is located close and parallel to the real ground, actual value of the conductivity has to be included within the numerical model. This proves to be a rather challenging task, as the numerical solution of the resulting convolution integrals dramatically increases the computation time of the overall method. This paper represents an introductory material that explains the problem and presents relatively simple modification of the GB-IBEM, necessary for the ground losses to be included in the numerical model, while the subsequent papers will address the issues of the computational efficiency.