Vector vs. raster representations of 3D ridges for propagation modeling over terrains

Abstract

Digital terrain elevation data (DTED) is usually represented in raster form where the elevations are given at each cell (or point) in a regular grid. Raster forms are simple and widely used for radio propagation modeling. But a raster form does not explicitly have some key terrain features which are important to propagation modeling, such as peaks and ridges. In this paper, we propose a vector form terrain model which directly represents three-dimensional terrain structures (e.g., ridges) and can provide more accurate description of the propagation environments. It can also improve the accuracy for the calculation of diffracted field due to mountainous structures. The advantages and drawbacks of the vector form terrain model are discussed.