Radar is a system used to pinpoint the location, speed, or course of an object. Radar 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 radar was truly used.

Radar works by sending radio waves into the air, which are reflected back by the object and interpreted by a receiver. Radar has an almost unlimited range, since radio waves can be amplified using several mechanisms. There are basically five types of radar:

• Detection and search radar: such as the "early warning radar," which is used for long-range detection of objects, and the Target Acquisition (TA) Radar Systems, used to locate surface-to-air missiles (SAM). These types of radar are frequently used in the military and in coastal surveillance, as well as for detecting car speed during highway patrol.

• Missile guidance systems are radar used to locate the target of a missile. This is often present in military aircraft.

• Radar for biological research: bird and insect radar are used frequently by scientists to track the migration patterns of animals. 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: used by airports to ensure the safety of planes, this type of radar 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: mostly used to measure and locate precipitation, this type of radar can also measure wind direction and speed.