• F2 layer is a thin black line, often embedded
in a red or green line.
• Propagation is best on frequencies having multiple
horizontal reflecting red/green layers. (These are not actual reflecting layers. They are produced by multiple bounces between the F2 and the ground.)
• F2 layers with higher altitudes produce weaker signals
than F2 layers with lower altitudes. (400 vs 350 km for example)
• A thick E layer (below 150 km) can produce
excellent propagation when there is no F2 layer.
• Vertical "rain" indicates a weak reflecting layer
with increased atmospheric noise.
• Vertical artifacts below 150 km are foreign or
domestic broadcast stations.
Ionogram provided by UML Space Science Lab