Ionospheric high frequency wave propagation using different IRI hmF2 and foF2 models

Abstract

High frequency (HF) electromagnetic wave propagation is commonly used in long-distance communication and detection. The ionosphere is a highly variable medium affecting this propagation. However, mean climatological conditions are useful in order to determine a “base level” for the design and operation of systems using HF waves that propagate in the ionosphere. Important variables that determine these conditions are the ionosphere peak height, hmF2, and F2 critical frequency, foF2. In the present work the effect of different hmF2 and foF2 model options in IRI-2016 and its spatial variability are analyzed through the analysis of the ground range and reflection height of HF ray paths using a numerical ray tracing method. The model options are M(3000)F2, AMTB and SDMF2 for hmF2, and URSI and CCIR for foF2. We perform this study for a quiet day, April 26 at 12 LT, and solar activity maximum conditions. Ground range and reflection height variation between values obtained with the different model options are on average not greater than ~40%, but can be higher for a Pedersen ray case. These variations are in general much stronger than those obtained when Earth's magnetic field is neglected in ray path assessments. However, while the magnetic field effect is of “physical” origin that has always the same sign, the effect of changing a model used for certain parameter's estimation depends on the model performance which may vary with location and time.