The word radar is an abbreviation for radio detection and ranging. It uses the reflection of electromagnetic waves to detect an object at a distance that cannot be observed visually. From its serious use in 1940s.
During the world war two where it allowed the British Air Force to detect German bomber before they become visible and to intercept them.Modern Radar is capable of detecting the presence shape and motion of ships, aircraft land vehicles and people at distances ranging up to hundreds and thousands of miles, depending on the conditions.Radar is based on the principle that high frequency RF signals are reflected by conductive targets. The most usual targets are airplanes, missiles, ships and automobiles. renault onderhoud . Pearl Jewellery . In a radar system, a signal is transmitted toward the target. The reflected signal is picked by receiver in a radar unit. The reflected or returned radio signal is called an echo. Marquee Wedding . The radar unit can then determined the distance to the target. Its direction or azimuth, and in some cases, its elevation or distance above the ground.