is a phenomenon where stations in a distance of 900 (rarely less) to 2500 km suddenly appear with strong signals. This usually occurs during the summer months during daytime or the evening. It's like a window suddenly open to another area. And this window can move. So in Germany it can start with stations from Madrid, then move to Valencia, one hour later Sicily and Tunisia appear. Select 'Sporadic E in the parameter menu' and see which stations are most likely to appear. The powerful ones centered around 1700 km get the highest index. It's recommended to limit the frequency range.