A very short distance dynamic diversity experiment

The objective of this experiment is to carry out a study of the rapid fading and enhancements (scintillations), simultaneously experienced by two Ka band receivers 9 metres apart. The signal source is, in this case, the beacon transmission at 20.7 GHz of the UF09 geosynchronous satellite from the US American Defence Department. The receivers are located at the UK Chilbolton Observatory in Hampshire. On-site digital signal processing permits display of the main investigated functions (time series, cross-correlation, power spectral densities, standard deviations, etc.). Fast data storage takes also place on-site, and on-line web control permits remote data monitoring, acquisition and presentation of results. Other data acquired included ground temperature and wind velocity. As regards results, analysis of the running cross-correlation indicates that for a non-negligible amount of time there is a significant negative correlation between the signals of both receivers, permitting to consider some form of dynamic diversity gain over few dBs. Often however, both signals are either hardly correlated (including the case of rain), or reasonably well correlated. This paper summarizes the installation of the receptor, the development of the data acquisition system and the preliminary results.