Seasonal Variations of the Optimum Reliable Frequencies During Maximum and Minimum Periods of Solar Cycle 24


  • Samar Abdalkaream Thabit University of Information Technology & Communication.
  • Loay E. George University of Information Technology & Communication.
  • Khalid A. Hadi Department of Astronomy & Space, College of Science, University of Baghdad.



In this research, the seasonal Optimal Reliable Frequency (ORF) variations between different transmitter/receiver stations have been determined. Mosul, Baghdad, and Basra have been chosen as tested transmitting stations that located in the northern, center, and southern of Iraqi zone. In this research, the minimum and maximum years (2009 and 2014) of solar cycle 24 have been chosen to examine the effect of solar activity on the determined seasonal ORF parameter. Mathematical model has been proposed which leads to generate the Optimal Reliable Frequency that can maintain the seasonal connection links for different path lengths and bearings. The suggested ORF parameter represented by a different orders polynomial equation. The polynomial equation has been determined depending on different selected parameters (path length, bearing, time (day), months and BUF values). The suggested seasonal ORF parameter was examined for the three stations of the adopted years. The value of the seasonal ORF ionospheric parameter increased with the increase of path length and varies with the bearing between the transmitting and receiving stations also, the seasonal ORF values were higher at maximum solar cycle (2014) than the minimum solar cycle (2009).


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Author Biography

  • Samar Abdalkaream Thabit, University of Information Technology & Communication.
    astronomy and space department


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Key Dates





Original Article

How to Cite

S. A. Thabit, L. E. George, and K. A. Hadi, “Seasonal Variations of the Optimum Reliable Frequencies During Maximum and Minimum Periods of Solar Cycle 24”, Al-Mustansiriyah Journal of Science, vol. 31, no. 4, pp. 15–27, Dec. 2020, doi: 10.23851/mjs.v31i4.887.