@article{MAKHILLRJAS2012799245,
    title = {Variability of the Critical Frequency of the F<SUB>2</SUB> Layer, foF<SUB>2</SUB> in West Africa using Ionosonde Stations at Ouagadougou and Dakar},
    journal = {Research Journal of Applied Sciences},
    volume = {7},
    number = {9},
    pages = {474-480},
    year = {2012},
    issn = {1815-932x},
    doi = {rjasci.2012.474.480},
    url = {https://makhillpublications.co/view-article.php?issn=1815-932x&doi=rjasci.2012.474.480},
    author = {O.R. and},
    keywords = {Ionosphere,variability of foF2,critical frequency,equatorial input,West Africa},
    abstract = {The critical frequency of the F<SUB>2</SUB> layer of the ionosphere, foF<SUB>2</SUB> is responsible for various effects on radio communication such as refraction, scintillation, absorption, error in Global Positioning System (GPS), jitter and phase delay. The variations of the critical frequency of the F<SUB>2</SUB> layer at two different locations over West Africa were studied using ionosonde data for a solar cycle (1979 to 1989) at low, moderate and high solar activity, 1986, 1983 and 1989, respectively. The ionosonde stations are Dakar in Senegal (15&deg;N, 17&deg;W) and Ouagadougou in Burkina Faso (12&deg;N, 1.8&deg;W). The investigation of critical frequency of the F<SUB>2</SUB> layer, foF<SUB>2</SUB> using Relative Standard Deviation (RSD) revealed the spread and the occurrence of foF<SUB>2</SUB>. The results obtained in this study are proposed as equatorial input values for the development of a Variability Model for the International Reference Ionosphere.}
    }