Results and implications from ITALSAT propagation experiment measurements at the CCLRC-Chilbolton Observatory

We have shown that measurements of atmospheric loss along a slant path provide information that is vital to system designers striving to maximise the performance to be obtained from communication systems operating at Ka-band and V-band frequencies. These are systems in which low fade margins inevitably constrain availability, and fade mitigation techniques are developed to counter the effects of deep fades caused by rain. These measurements have shown that, at V-band, attention must also be paid to the attenuating effect of light rain and cloud - both can be significant sources of signal loss. To fully appreciate the true nature of the dynamic aspects of atmospheric induced fades it is apparent that measurements collected over extended periods provide the true nature of fade slope, fade/interfade duration, and the relationship between signals at different frequencies. It is an acknowledged fact that propagation prediction procedures need to be rigorously tested against real measurements in order to be credible, and useful, to system design engineers. The V-band measurements collected at the Chilbolton Observatory in southern England are being used to perform that role.