Radar mainly uses radio waves for its operation. Radio waves are a type of electromagnetic wave that lies in the radio frequency portion of the electromagnetic spectrum. These waves have wavelengths ranging from millimeters to meters and propagate through the atmosphere and space at the speed of light. Radar systems emit radio waves from an antenna and detect their reflections from objects to determine the presence, location, and characteristics of those objects.
Radar systems use specific radio wave frequencies depending on their operational requirements and applications.
Commonly used frequencies include S-band (2 to 4 GHz), X-band (8 to 12 GHz), and Ku-band (12 to 18 GHz). Each frequency band offers advantages in range, resolution, atmospheric penetration and interference rejection, allowing radar systems to be adapted for different uses such as air traffic control, weather monitoring and military surveillance.
Doppler radar uses microwaves, which are a subset of radio waves with higher frequencies typically ranging from 1 to 300 GHz.
Microwaves used in Doppler radar systems allow the measurement of Doppler shift, which is the change in frequency of the radar signal reflected from a moving target. By detecting this frequency shift, Doppler radar systems can accurately determine the speed and direction of moving objects, such as aircraft, weather systems or vehicles.
Sonar, which stands for Sound Navigation and Ranging, uses sound waves for its operation. Specifically, sonar employs underwater acoustic waves, which are mechanical waves that travel through water.
These waves have frequencies generally ranging from a few hundred Hertz to several tens of Kilohertz. Sonar systems emit pulses of sound waves into the water and detect their reflections from underwater objects, enabling the detection of submarines, underwater terrain and marine life. Sonar technology plays a crucial role in naval operations, underwater exploration, fisheries management and maritime research