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E3B13

RADIO WAVE PROPAGATION · Transequatorial propagation; long-path propagation; ordinary and extraordinary waves; chordal hop; sporadic-E mechanisms; ground-wave propagation

E3B13E3B →

What type of polarization is supported by ground-wave propagation?

  1. AVertical
  2. BHorizontal
  3. CCircular
  4. DElliptical
Why Ground-wave (surface-wave) propagation depends on the wave clinging to the boundary between air and the conducting earth. A horizontally polarized electric field runs parallel to that conductive surface, so the ground effectively short-circuits it and the wave dies within a short distance. A vertical electric field is perpendicular to the ground and survives, which is why AM broadcast and 160/80 meter surface-wave work uses vertical antennas over good ground or a radial system.
Watch out Horizontal polarization is the usual choice for HF skywave dipoles and beams, but at ground level those signals are absorbed almost immediately, so they contribute nothing to surface-wave range. Circular and elliptical polarization are terms from satellite and VHF work, not surface-wave propagation.
Ground wave wants the E-field standing up: vertical polarization. Lay it flat and the earth shorts it out.
HamSandwich explanation, first draft. The question and answers are the NCVEC text.
← E3B12 All of E3B

The rest of E3B

  1. E3B01 Where is transequatorial propagation (TEP) most likely to occur?
  2. E3B02 What is the approximate maximum range for signals using transequatorial propagation?
  3. E3B03 At what time of day is transequatorial propagation most likely to occur?
  4. E3B04 What are "extraordinary" and "ordinary" waves?
  5. E3B05 Which of the following paths is most likely to support long-distance propagation on 160 meters?
  6. E3B06 On which of the following amateur bands is long-path propagation most frequent?
  7. E3B07 What effect does lowering a signal's transmitted elevation angle have on ionospheric HF skip propagation?
  8. E3B08 How does the maximum range of ground-wave propagation change when the signal frequency is increased?
  9. E3B09 At what time of year is sporadic-E propagation most likely to occur?
  10. E3B10 What is the effect of chordal-hop propagation?
  11. E3B11 At what time of day is sporadic-E propagation most likely to occur?
  12. E3B12 What is chordal-hop propagation?
  13. E3B13 What type of polarization is supported by ground-wave propagation?
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