| A | B |
|---|
| Radar | Radio Detection and Ranging. It is used to get information about distant objects like distance, speed, direction and shape |
| Antenna | sends out waves, and receives waves that have bounced off something |
| Echoes | returning radio waves |
| Display | lets people see the information that the radar system has collected. |
| Doppler Shift | a change in the frequency of the waves emitted by the direction of a moving object |
| Pulse Radar | transmits waves in short bursts, receiving echoes in the time between transmissions |
| Radio Waves | received by an antenna, they are invisible waves that each travel at a different frequency, used to broadcast sounds and pictures |
| Transmitter | used to change or modulate a carrier wave, it comes from a microphone that translates sounds into electrical signals |
| Carrier Wave | determines where you'll find the signal on your radio dial |
| Receiver | picks up radio waves and converts them back into electrical signals, it separates the signals from the carrier wave, amplifies the signals and then plays them through a speaker, which converts them back into sound |
| AM | (amplitude modulated) the signal is measured by it's amplitude, or height. They are long and shallow, making them low frequency waves. |
| FM | (frequency modulated) signal is measured by it's frequency, or the number of waves per second. They are high frequency waves that have a short wavelength. |
| Ionosphere | a part of the Earth's atmosphere, stretches from 50-80km above the Earth's surface. Low frequency waves travel by bouncing off of it. High frequency waves bounce through it, so satellites are used to bounce the waves back through. |
