Radar is a system used to pinpoint the location, speed, or course of an object. It can be used to track anything from aircraft to weather formations. It can also be used to detect speeding traffic, wind speed, and uneven terrain. The term RADAR is an acronym meaning Radio Detection and Ranging, although the term is now used as a single word rather than an abbreviation. The first radar patent was filed in 1904, but it wasn't until the Second War World that the system was truly used.
A radar system works by sending radio waves into the air, which are reflected back by the object and interpreted by a receiver. It has an almost unlimited range, since radio waves can be amplified using several mechanisms. There are basically five types:
- Detection and search radar includes the "early warning radar," used for long-range detection of objects, and the Target Acquisition (TA) Radar Systems, used to locate surface-to-air missiles (SAM). These types are frequently used in the military and in coastal surveillance, as well as for detecting car speed during highway patrol.
- Missile guidance systems are used to locate the target of a missile. This is often present in military aircraft.
- Radar for biological research includes tracking birds and insects to trace their migration patterns. Bird radar is also being used at NASA's Kennedy Space Center in Florida to track the presence of birds, especially vultures, near launching pads. Trap and release programs have been implemented to prevent birds accidentally impacting the shuttles after liftoff.
- Air traffic control and navigation radar is used by airports to ensure the safety of planes. This type detects the proximity of an aircraft and identifies the identity and altitude of the plane. Radio beacons and Distance Measuring Equipment (DME) also fall into this category.
- Weather-sensing radar systems are mostly used to measure and locate precipitation. They can also measure wind direction and speed.