Fot

In this chapter, the results that have achieved from the modelestablished in this research project work are presented. The predictionmodel have been made by using the international prediction model(REC533 model). The established model is used to calculate the frequencyof optimum traffic (FOT).The calculations of frequency of optimum traffic (FOT) for theMiddle East region have been divided in to two zones according on theirdistances from the transmitting point (Iraq, Baghdad). For every zone, thepredicted results achieved from the established model have been made fourrelationships between the frequency of optimum traffic (FOT) and theeffective parameters shown above. These results have been represented byusing the graphical diagram.The radius of the first studied zone was taken 1000 Km fromBaghdad site and in four directions. From the results listed in chapter four,it can be concluded that the daily FOT values are greater than those atnight hours. The local time variation of FOT with respect to direction, isrelatively high along south direction, this is due to strong variation in theionosphere when moving south toward Equator (due to the solar radiationwhich strikes the Atmosphere with less solar zenith angle). So trying toestablish HF-link passing over Arabian Gulf zone and near the equatorialline must be a ware from the strong variation in the electron distribution inthese areas where causes high absorption of long radio waves.Also for December month (Winter season) the range of frequenciesis between 6 and 22 MHz for high solar activity, and (6-19 MHz) for lowsolar activity where the minimum value represents the FOT value forsunrise time. Also at sunrise time FOT values not affected by the variation