Radar Basics

Air-Defense Radars

Air-Defense Radars can detect air targets and determine their position, course, and speed in a relatively large area. The maximum range of Air-Defense Radar can exceed 300 miles, and the bearing coverage is a complete 360-degree circle. Air-Defense Radars are usually divided into two categories, based on the amount of position information supplied. Radar sets that provide only range and bearing information are referred to as two-dimensional, or 2D, radars. Radar sets that supply range, bearing, and height are called three-dimensional, or 3D, radars.

Air-Defense Radars are used as early-warning devices because they can detect approaching enemy aircraft or missiles at great distances. In the case of an attack, early detection of the enemy is vital for a successful defense against attack. Antiaircraft defenses in the form of anti-aircraft artillery (abbreviated to „AAA”), missiles, or fighter planes must be brought to a high degree of readiness in time to repel an attack. Range and bearing information, provided by Air-Defense Radars, used to initially position a fire-control tracking radar on a target.

Figure 2: Diagram of a typical 2D-Radar, the rotating cosecant-squared antenna pattern.

Figure 2: Diagram of a typical 2D-Radar, the rotating cosecant-squared antenna pattern.

Another function of the Air-Defense Radar is guiding combat air patrol (CAP) aircraft to a position suitable to intercept enemy aircraft. In the case of aircraft control, the guidance information is obtained by the radar operator and passed to the aircraft by either voice radio or a computer link to the aircraft.

Major Air-Defense Radar Applications are:

• Long-range early warning (including airborne early warning, AEW)
• Ballistic missile warning and acquisition
• Height-finding
• Ground-controlled interception (GCI)