An impedance UTD model for the prediction of terrain undulation and roughness effects in radiating systems

A feasibility study of evaluating the terrain effects on radiating systems using analytical and computational techniques is presented. The problem of site effect evaluation is divided into three stages: terrain modelling, ray tracing and field evaluation. Innovative techniques are introduced at each stage to make the model versatile enough to handle most general terrain contours and also reduce computational requirements to a minimum. The result is a scheme that can evaluate most terrain types on a mini/micro computer. The model developed is applied to study the site effects on two important electromagnetic systems for navigation and position location: the instrument landing system (ILS) and the microwave landing system (MLS). A summary of results for actual sites is presented