Interference Measurements in a Rail Environment

Abstract

It is hard to beat an established system. With this conclusion Europe started to built up the new independent navigation system GALILEO. The established GPS system has to be outperformed to guarantee a good market position. In terms of navigation systems this means clearly: More bandwidth, new frequency bands and new services. But bandwidth was rare and many frequency bands are occupied. The only solution was a share with other services such as DME services. The remaining question was: How silent are the new frequency bands? Interference problems with GPS made clear: Even the well established L1 band might not be as quiet as assumed. Therefore the German Aerospace Centre (DLR) carried out a measurement campaign in the GJU funded GIRASOLE project and performed a measurement campaign in rail, maritime and land mobile environments. The huge amount of data was pre processed to extract the interferers out of the sampled signals. The interference was classified by periodogram estimations and DBSCAN clustering. The result provides a valuable preview what GALILEO will be faced with when the system will be operational.