A mixed-path groundwave field-strength prediction virtual tool for digital radio broadcast systems in medium and short wave bands

The emerging digital technologies for the communication bands from LF up to VHF - bands traditionally used by analog radio systems - necessitate revisiting early analytical propagation methods, and urge engineers to develop novel propagation prediction tools. Existing analytical propagation techniques are based on ray-mode approaches and the Millington curve-fitting approach for mixed-path propagation. These have been endorsed and are used in related ITU (formerly, CCIR) recommendations. These techniques are discussed, with characteristic examples produced via a newly introduced MF/HF groundwave propagation prediction virtual tool (GPVT)