Backscatter

A form of radio wave propagation which occurs when the MUF maximum usable frequency rises above the 30MHz. Radio Waves are reflected towards the earth’s surface at a larger detectable continuum of angles than usual. A detectable fraction of a radio signal is now reflected at a very sharp angle back into region just surrounding the transmitting station but usually beyond the range of ground wave communications. Backscatter signals are generally weaker than the normal reflected radio waves and during periods of low solar flux while during periods of very high solar flux, even small stations may produce readable signals. Backscatter signals are generally very stable and rarely influenced by QSB. Backscatter signals are easily distinguishable as they resemble a “hollow” or “barrel” sound.