Reconstruction of the Earth Surface Potential Distribution Using Radial Basis Functions

摘要

A credible reconstruction of a continuous two-dimensional earth surface potential distribution from a discrete set of noisy samples is essential for correct identification of regions with high values of touch and step voltages, as a part of grounding grid safety assessment procedure. This research provides some new and useful insights on the earth surface potential distribution reconstruction quality, focused mainly on the most commonly used radial basis function (RBF) interpolation kernels. The RBF approach to reconstruction was chosen because of the underlaying algorithm simplicity and the fact that it provides natural mathematical framework for smooth interpolation and approximation of potential fields from irregular sampling sets. Since the quality of potential distribution reconstruction is heavily influenced by the choice of interpolation method, sampling layout and a priori knowledge of the grounding grid structure under test, this research also elaborates some heuristic guidelines for planning proper sampling procedure and illustrates some examples of reconstructed functional shape distortions due to poor sampling layouts.