Radar systems are used over a wide range of frequencies in the electromagnetic spectrum, depending on the specific application and operational requirements. The frequency range for radar extends from very low frequencies (VLF) of approximately 3 kilohertz (kHz) to extremely high frequencies (EHF) exceeding 100 gigahertz (GHz). The choice of frequency band depends on factors such as desired range, resolution, atmospheric conditions and the type of targets detected.
For example, air traffic control radars typically operate in the L-band (1-2 GHz) or S-band (2-4 GHz), providing good atmospheric penetration and range for tracking aircraft over long distances. .
Aircraft radar systems, commonly called weather radars or weather avoidance radars, typically operate in the C-band (4-8 GHz) or X-band (8-12 GHz). These radar systems are designed to detect and display weather conditions, including precipitation, storms and turbulence, to pilots in flight.
The frequencies used by aircraft radio are chosen to optimize performance in detecting and avoiding bad weather, providing accurate and timely information to improve flight safety and efficiency. C-band and X-band radar systems provide high resolution and sensitivity to detect large-scale weather features and potential hazards in airspace.
Radar uses electromagnetic waves, particularly microwave signals, for its operation. Microwave signals are transmitted from the radar antenna as short pulses of electromagnetic energy.
These pulses propagate through space until they encounter an object, such as an airplane, vehicle, or precipitation particles. When microwave pulses strike an object, they are reflected back to the radar antenna, creating an echo. By measuring the time it takes for the pulses to travel to the object and return (flight time), radar systems calculate the distance to the target.
Analysis of the returned signals also provides information on the direction, speed, size and shape of detected targets.
Frequency bands used by radar systems are typically classified in terms of Gigahertz (GHZ), representing billions of cycles per second. Radar bands can span a wide range of frequencies, from a few gigahertz to tens of gigahertz or more, depending on the specific application and technology requirements. For example, radar bands may include L-band (1-2 GHz), S-band (2-4 GHz), C-band (4-8 GHz), X-band (8-12 GHz), Ku- band (12-18 GHz) and ka band (26.5-40 GHz).
Each radar band offers unique characteristics in terms of range, resolution, sensitivity and performance in different environmental conditions, allowing radar systems to be tailored to specific operational needs in various industries and applications