A radio-echo sounding system consists of two main components: 1) the transmitter, and 2) the receiver. The transmitter sends out a brief burst of radio waves of a specific frequency. The receiver detects the radio waves from the transmitter and any waves that have bounced, or reflected off nearby surfaces. The receiver records the amount of time between the arrival of the transmitted wave and any reflected waves as well as the strength of the waves (measured as an AC voltage).
The radio waves travel at different speeds through different materials. For example, radio waves travel very close to 300,000,000 meters/second (3 x 108 m/s) through air, a little less than double the speed in ice at 1.69 x 108 m/s.
