How does RADAR work?

How does RADAR work?

• A. Detects presence of an object and determines direction, altitude and range by reflected electromagnetic energy
• B. Uses sound waves to measure distance
• C. Requires visible light
• D. Detects only metal objects

Answer: (A)

Radar works by emitting pulses of radio energy and listening for echoes. When those pulses encounter an object, part of the energy is reflected back to the radar receiver, and the time between transmission and reception tells you how far away the object is (range). The direction to the object comes from where the radar’s antenna beam is pointed or how it is scanned, giving you the bearing or azimuth. Altitude can be inferred from the elevation angle of the beam and the geometry, or from additional height-measuring radar systems. The key idea is detecting presence and geometry solely from the reflected electromagnetic energy. This differs from using sound waves (sonar), from relying on visible light, or from the notion that radar only detects metal objects, since radar can detect many materials and shapes that reflect energy.

Radar works by emitting pulses of radio energy and listening for echoes. When those pulses encounter an object, part of the energy is reflected back to the radar receiver, and the time between transmission and reception tells you how far away the object is (range). The direction to the object comes from where the radar’s antenna beam is pointed or how it is scanned, giving you the bearing or azimuth. Altitude can be inferred from the elevation angle of the beam and the geometry, or from additional height-measuring radar systems. The key idea is detecting presence and geometry solely from the reflected electromagnetic energy. This differs from using sound waves (sonar), from relying on visible light, or from the notion that radar only detects metal objects, since radar can detect many materials and shapes that reflect energy.