LORAN-C Positioning Errors Caused by Scattering from Wires Above the Earth

In this paper, the scattering of a LORAN-C navigation signal by a powerline is calculated. The results of the derivation can be used to predict positioning errors for land-based applications of LORAN-C, such as vehicle-location schemes. The only assumptions are that the line spacing is small compared to its height and that the LORAN-C signal is narrow band, and not incident at a grazing angle. From this general result, a very simple theory for predicting positioning errors is derived which is valid for most parameters of interest. It is found that, when a LORAN-C receiver is located near a powerline, position errors of 1 km are possible. This value is in accord with published experimental results. Further, it is shown that position errors are significantly greater when the LORAN-C signal approaches the transmission line at a small angle.