# Using High Frequency Propagation to Calculate Basic Maximum Usable Frequency

## TL;DR

This study compares observed and predicted ionospheric data for the F2-layer using the IRI model, focusing on high frequency propagation and BMUF, across different solar activity levels at a mid-latitude station.

## Contribution

It evaluates the accuracy of the IRI model in predicting BMUF and foF2, introducing correction factors to improve prediction during varying solar activity periods.

## Key findings

- Good correlation between observed and predicted foF2, except in specific months.
- High correlation for BMUF during low solar activity years.
- Correction factors improve BMUF prediction accuracy.

## Abstract

A comparison between observed (obs.) digital ionospheric sounding data and predicted (pre.) using International Reference Ionosphere (IRI) model for critical frequency (foF2) and Basic Maximum Usable Frequency (BMUF) of ionospheric F2-Layer has been made. A mid-latitude region selected for this research work by using data from station Wakkanai ($45.38^{o} N$, $141.66^{o} E$). This study included 12 monthly median data from year (2001, $R_{12}=111$) selected for high Sunspot number (SSN) and years for low SSN (2004, $R_{12}=44$) and (2005, $R_{12}=29$). Frequency parameters foF2 reveals that there is a good correlation between observed and predicted except for January of years 2001 and 2004, and BMUF revealed that there is a good correlation between observed and predicted for years of low SSN and all months except in month 1, 9 and 12 of year 2004, for year 2001 of high SSN there is a bad correlation. A correction factor as a function of time used from fitting technique to correct the predicted value with observed value of BMUF for year 2001.

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Source: https://tomesphere.com/paper/1908.01836