E-Skip

Related wiki pages : Propagation, Meteor scatter, Aurora, Tropospheric ducting

What is it?
The E-layer is the lowest layer of the atmosphere and can typically be found at altitudes between about 80km and 100km. the E-Layer is characterised by high electron densities, and high temperatures (between 300K and 122K)

E-Skip propagation is the reflection of radio waves off the E-Layer, allowing reception many thousands of kilometres distant from normal reception areas.

E-Layer communications are characterised by:
 * weaker but longer paths than usual
 * directions for optimal communications, and hence target areas are predictable
 * time frames for communications are predictable
 * QSB (fading) is slow and predictable

At which frequencies does E-Skip occur?
E-Skip generally occurs at night in the medium and shortwave HF parts of the spectrum.

Sporadic E-Skip
Sporadic E-skip is associated with scattered regions of especially dense ionisation that occur seasonally within the E-layer. generally it occurs:


 * daily during the day in equatorial regions
 * commonly in temperate regions in late spring, early summer and sometimes in early winter
 * in association with auroras in Polar regions
 * at frequencies up to about 150MHz
 * can provide communication over distances up to 2,400Km

Sporadic E-Skip is characterised by:
 * strong, relatively short paths
 * unpredicatable times
 * unpredictable directions
 * fast and unpredictable QSB (fading) events