Abstract: | Measurements of propagation effects on satellite down-links to tropical locations are rare. This paper describes two experiments that will provide new and useful data for radiowave propagation in tropical Africa. A discussion of the African tropical climate is included that shows the wide range of rainfall patterns throughout the continent. Also, the broad distribution of climate in Mali, the West African country where the experiments will be located, is described. A rain-rate measurement programme involving autonomous terminals based on tipping bucket rain-gauges is presented. An experiment measuring the slant-path attenuation of the 12·5 GHz beacon of the ESA satellite OLYMPUS is described. The paper also discusses how the measured data in both experiments will be relayed daily from Mali to Virginia Tech by the low earth orbit satellite VaSTAR. |