Ridge feature extraction and effect on radio propagation for wireless communications

When diffraction of ridges is required for predicting radio signal in mountainous regions, the realistic shape of ridges is often simplified (e.g., as a knife edge or a wedge). Also, the ridge orientation is usually ignored and the EM waves are assumed to be normally incident on the ridge. As more accurate radio propagation prediction is needed for advanced wireless communications, it is necessary to take into account more realistic features of ridges. For example, the slopes and orientation of ridges should be considered as two key features since they directly affect the values of diffraction coefficients. In this paper we present methods to extract these features of ridges based on digital terrain elevation data. The effect of the ridge orientation on the diffracted field is then investigated.