Determination of the Annual Optimal Reliable Frequency for Different Transmitter/Receiver Stations Distributed over the Iraqi Territory

Abstract

This paper aimed to determine the Optimal Reliable Frequency (ORF) that can maintain certain connection link between different transmitter/receiver stations laid over the Iraqi territory. Three different transmitting sites were chosen as tested stations located in the northern, central, and southern regions of Iraq. These sites are Mosul, Baghdad, and Basra, respectively. In this study, the years 2009 and 2014, which represent the minimum and maximum years of solar cycle 24, were chosen to examine the effect of low and high solar activity on the determined ORF. The datasets of the Best Usable Frequency (BUF) were calculated using the ASAPS international communication model. An analytical study was made on the generated BUF parameter dataset of the annual time for the adopted years. Also, an analytical simulation was made for the suggested ORF parameter depending on the BUF parameter datasets. The results of this simulation showed that the suggested ORF parameter can be represented by polynomial equation of different orders. The suggested formula was determined depending on different tested parameters (path length, bearing, time (day) and BUF values). For this purpose, a certain program was built using a visual basic programing language (VB6). The suggested ORF parameter was investigated for the annual time for the three sites of the years 2009 and 2014.

Examining the Seasonal Correlations Among Different Ionospheric Indices During Solar Cycle Twenty-Four

“…The ionospheric parameter determines the optimum range of frequencies (HF) reflected from the ionospheric layers between two terminals at a certain moment. There are many important parameters in HF ionospheric communications that can be used to maintain the connection links between two terminals [11][12][13]. Following are the definitions of some ionospheric communications parameters that will be adopted in this research:…”

“…The Best Usable Frequency (BUF) refers to the frequency at which a radio wave can be transmitted and received most effectively over a given distance at a particular time. It can be defined as the frequency from a specified set that offers a maximum signal-to-noise ratio (S/N) while also satisfying the specified minimum take-off angle, required S/N ratio, and probability level [12].…”

Evaluation of the Annual Correlations between Different Solar-Ionospheric Indices During Solar Cycles 23 and 24

“…Thabit, S. A., et al ( 2021) have identified the Optimal Reliable Frequencies (ORF) of the year for various transmit/receive stations located in various regions in Iraq. The calculated parameter values are based on observations of the ionosphere (T-index) and the results of this simulation show that the proposed ORF parameters are represented by polynomial equations of different orders [18].…”

Investigation of the Electron Coefficients of (Ar, He, N2, O2) Gases in the Ionosphere

“…The ionosphere layer in the upper atmosphere is a primary source of a real ionization neutral particles plasma [7][8] . The ionosphere is made up of different layers due to the different wavelengths in the sun's ultraviolet spectrum 9 . During the day, the solar flux and electron density increase in the ionosphere.…”

“…BOLSIG+ was used to calculate the electronic coefficients and collapse voltage gradient for the environment of the planetary System, as well as solve the Boltzmann equation 15 . The ionosphere's layers differ due to different wavelengths in the sun's ultraviolet spectrum 9 . Earth's ionosphere is made up of three parts: D (50-90) km, E (90-150) km, and F (150-500 km) 12 .…”