G3C - Radio Wave Propagation
General Class
Ionospheric layers and characteristics; critical frequency; HF propagation
11 questions
Which ionospheric region is closest to the surface of Earth?
What is meant by the term “critical frequency” at a given incidence angle?
Why is skip propagation via the F2 region longer than that via the other ionospheric regions?
What does the term “critical angle” mean, as applied to radio wave propagation?
Why is long-distance communication on the 40-, 60-, 80-, and 160-meter bands more difficult during the day?
What is a characteristic of HF scatter?
What makes HF scatter signals often sound distorted?
Why are HF scatter signals in the skip zone usually weak?
What type of propagation allows signals to be heard in the transmitting station’s skip zone?
What is near vertical incidence skywave (NVIS) propagation?
Which ionospheric region is the most absorbent of signals below 10 MHz during daylight hours?