Meteorological and Terrain Effects on RF Propagation

Both terrain profile and near-ground meteorological conditions can have significant effects on the propagation of Radio Frequency (RF) radiation, especially for near-ground propagation paths. High-resolution terrain data obtained from the United States Geological Survey (USGS), and range-dependent gradient of the lower atmospheric refractive index calculated from near real-time weather data from the National Oceanic and Atmospheric Administration (NOAA) were used as inputs to the Aerospace Radio Frequency Propagation Tool (APRT) propagation model. Field measurements show that the model using the near real-time weather data generates more accurate propagation loss predictions than the model using constant weather data.