3-68K4 A
What is the main underlying operating principle of an aircraft's Distance Measuring Equipment (DME)?
A. A measurable amount of time is required to send and receive a radio signal through the Earth's atmosphere.
B. The difference between the peak values of two DC voltages may be used to determine an aircraft's distance to another aircraft.
C. A measurable frequency compression of an AC signal may be used to determine an aircraft's altitude above the earth.
D. A phase inversion between two AC voltages may be used to determine an aircraft's distance to the exit ramp of an airport's runway.
