E3B12 - What is chordal-hop propagation?

Question

What is chordal-hop propagation?

Answer Options

  • A) Propagation away from the great circle bearing between stations
  • B) Successive ionospheric refractions without an intermediate reflection from the ground
  • C) Propagation across the geomagnetic equator
  • D) Signals reflected back toward the transmitting station

Correct Answer: B


Explanation

Chordal-hop propagation is a special, highly efficient mode of long-distance communication on HF. Most multi-hop propagation involves the signal bouncing between the ionosphere and the Earth’s surface (I-G-I-G hops). This mode bypasses the signal degradation and scattering that occurs upon hitting the ground.

Chordal-hop propagation is defined as successive ionospheric refractions without an intermediate reflection from the ground. The radio wave is confined to the region between the maximum ionization level of the F-layer and the bottom side of the ionosphere, traveling along a ‘chord’ of the Earth’s circumference, providing cleaner, longer-distance communication.


This topic was automatically created to facilitate community discussion about this exam question. Feel free to share study tips, memory tricks, or additional explanations!