radiovågning

Radiovågning, or radio wave propagation, is the study of how radio waves travel through the Earth's atmosphere and beyond. It depends on frequency, environment, and time. The concept is central to wireless communication, broadcasting, radar, and navigation.

Ground wave propagation follows the Earth's surface, especially at low frequencies. It depends on ground conductivity and terrain, and attenuates with distance and frequency. At higher frequencies, ground waves diminish and line-of-sight becomes more important.

Line-of-sight propagation applies when the path between transmitter and receiver is unobstructed. At VHF and higher bands, antennas must be elevated to overcome curvature of the Earth, with range roughly limited by the horizon and terrain.

Skywave propagation uses the ionosphere to reflect or refract radio waves back to Earth, enabling long-range communication beyond line of sight. The ionospheric reflection is strongly affected by solar activity, time of day, season, and frequency, creating hours of good propagation or poor propagation.

Other effects include tropospheric propagation, ducting, diffraction over obstacles, multipath fading, atmospheric absorption, and rain fade at higher frequencies. Weather and atmospheric conditions can modify propagation characteristics for microwave and higher bands.

Practical uses and modeling: Engineers consider radiovågning when selecting frequencies, designing antennas, and planning networks. Propagation models and measurements help forecast link budgets and reliability.