Interference pattern for the radio path from HWU on 18.3 kHz to PI5FTS

Distance: 611.1 km

Interference pattern


This sine curve shows the interference pattern for this particular radio path as a function of the virtual height of the D-layer. At the top of the sine the ground wave and the sky wave are in phase, resulting in a higher signal strength of the received signal. At the bottom of the sine the ground wave and the sky wave have the opposite phase, resulting in a lower signal strength. With undisturbed conditions during the hours when the Sun is above the horizon, the virtual height of the D-layer is almost 80 km. During a Sudden Ionospheric Disturbance (SID), caused by e.g. a solar flare, the virtual height of the D-layer will temporarily be lower. At dawn and dusk the virtual height of the D-layer will be higher.

Last update: 2016-08-10