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
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 |