Last Updated on October 28, 2026 by John Berry
Ground wave path loss
Ground wave propagation is complex! The ground wave comprises three parts – a direct wave between transmitter and receiver, a reflected wave from the ground between the terminals, and a surface wave. The ground wave path loss, Lb is given by: Lb = 142+20logf -E. Here’s how it’s used.
Ground conductivity and relative permittivity
Ground wave propagation in the frequency range 10kHz to about 30MHz depends a lot on the characteristics of the ground and sea between the stations. Ground and sea are defined by their electrical permittivity, ε, and electrical conductivity, σ. Here’s how they are presented on atlases.
Ground wave path budget
The GRWAVE Fortran application was for many years the standard method for calculating path loss assuming ground wave propagation. In recent years, the ITU has deprecated GRWAVE. The current Recommendation, ITU-R P.368-10 (08/2022), names NTIA’s LFMF-SmoothEarth program as its official software. This budget calculator uses LFMF to compute ground wave margins for given distance or maximum ranges for zero margin. CALCULATOR