HF Propagation in Tropical Regions

The paper makes an analysis of the propagation of HF radio signal in a tropical region. The propagation of HF radio signal through the ionosphere is used widely in Nigeria, most especially within the airports. This paper surveys and highlighted the problems experienced by HF radio signal in its journey through the special ionosphere of a tropical region. Based on purely technical consideration, the efficiency of various modes of communication in any particular circumstances is dependent on a number of factors. Some of the more important ones are: transmission distance between terminal stations; the propagation mechanism involved and its susceptibility to fading effects and interference; the availability of frequency assignments; the channel capacity of the system and whether or not ´drop off´ facilities are to be provided at intermediate points; and the design and sitting of antenna arrays