IRI and VLF/LF radio service planning Original Research Article

Existing propagation models of the International Telecommunication Union are reviewed and it is shown that use of improved D-region electron-density height profiles to be embodied within IRI-2000 should lead to more accurate results. Additionally, attention is drawn to limitations in the ‘equivalent frequency’ concept contained within the wave-hop method which equates ionospheric reflection coefficients at related wave frequencies and angles of incidence.