PRINCIPALS OF SKY WAVE PROPAGATION
Critical Tasks: 01-5705.07-0003
In this lesson, you will learn about the fundamentals of sky wave propagation, specifically, the effects of
TERMINAL LEARNING OBJECTIVE:
State the factors involved in sky wave propagation.
Given this lesson.
To demonstrate competence, you must achieve 70 percent on the subcourse
REFERENCES: The material in this lesson was derived from FM 11-64 and FM 24-18.
Sky wave propagation is used to communicate over long distances. Sky wave propagation allows
transmitted signals to be reflected (bounced) off a portion of the Earth's ionosphere and picked up at a
receiver hundreds, or even thousands of miles away. A common example of this phenomenon is heard
on the AM broadcast band, when many distant stations can be heard after sunset or in the evening hours.
Signal officers must understand this propagation mode because they may have to establish
communications between a forward staging area in one country and an echelon of command in another.
Usually, the HF band is used for sky wave propagation.