E-Skip

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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

Further reading

Propagation and radio wave theory
Propagation Aurora * E-Skip * IPS * Lightning scatter * Meteor scatter * Satellites * Trans-Equatorial Propagation * Tropospheric ducting
Interference QRM * QRN
Theory Electromagnetic Waves * Frequency Wavelength and Period