The ionosphere is that portion of the atmosphere that lies between about 50 km and about 1000 km. For most of that altitude range the ionosphere lies well within the thermosphere. The bottomside ionosphere is defined as the region between about 90 km and 350 km, the upper limit corresponding to the height at which maximum electron density occurs within the ionosphere. This region has the natural property of reflecting radio waves and is, therefore, crucially important for High Frequency (HF) Radio Communications.
The Amateur Radio and Defence communities are the prime users of the ionosphere for HF radio communications. One of the problems experienced by these users is the lack of real time propagation information. There are many software packages to determine HF propagation conditions, and one of these is used within South Africa to display propagation conditions. However, there is a need for a real time indication of propagation, and also for an African developed propagation path prediction service.
The international beacon project is a system of beacons distributed around the globe operating in rotation on five different frequencies (14.1, 18.11, 21.15, 24.93, 28.2 MHz). The schedule and location for the beacons can be obtained from the website: http://www.ncdxf.org/Beacons.html
There is a receiving station for monitoring these beacons at the HMO. The data from this receiving station is collected, archived and displayed in real time on the HMO space weather website. The idea behind this project is to use the data collected in Hermanus for the African beacons to determine the feasibility of producing a propagation prediction facility for African Space Weather operations. Available is a newly developed ionospheric map which can be used to insert ionospheric conditions. The archived data will need to be processed into a useable form for developing such a model, and various modeling techniques will need to be employed to determine the most suitable.