Clear-air scintillation and multipath for low-elevation high-latitude satellite communication links

One year of measured beacon data at 20 GHz from 3 high latitude locations in Norway are analyzed and compared with existing scintillation models. Severe fading of up to 45 dB was recorded at Isfjord Radio, while fades below 8 dB were recorded at the other locations. The measured amplitude distribution becomes highly asymmetrical during severe fading. Long term fading levels for Vadsø and Røst are lower than predicted by ITU-R, but compare well with a modified model based on a previous measurement at high latitudes. The composite model used for Isfjord Radio gives lower predictions than the measured fading values. The fading levels are also higher than recorded during previous measurement at the same location at a lower frequency. The slope observed for deep fading matches well with the deep fading part of the ITU-R model. Monthly and daily variations are most severe at Isfjord Radio and virtually absent at Røst.