Radio Propagation Calculation: A Technique Using 3D Fresnel Zones for Decimeter Radio Waves on Lidar Data

This article discusses the Fresnel radio tool (FRT) model for radio-coverage prediction based on the Fresnel-zone calculation. The 3D Fresnel zones are calculated from the transmitter (Tx) source to each cell on a raster digital map. For numerical calculation purposes, Fresnel zones are cross sectioned to a finite number of fragments. The attenuation and phase shift of each segment can be adjusted according to the obstacle type. At the target receiver (Rx) point, contributions from each fragment, represented by complex numbers, are summed and converted to a signal strength.