Small Range Site Diversity Considerations Based on Long-Term Data from a Very Dense Rain Gauge Network

Site diversity is a technique used to improve the reliability of satellite communication systems, particularly during severe rain events. The technique works by linking two or more ground stations that receive the same signal and by compensating deep rain fades that occur in one station by another station where the signal is better at the time. In order to find ideal distances between the ground stations, the spatial correlation of rainfall is investigated based on long-term data from a very dense rain gauge network in the Alpine foreland of southeast Austria in the region of Feldbach. The dataset allows to investigate spatial rain correlation up to distances of 17 km. The data reveals that the correlation coefficient between the rain rate time series of two rain gauges drops below 0.5 if the instruments are more than 4 km away. For an individual year, a local minimum for the correlation was found at 13 km separation.