Doppler, Surveillance, Tracking… How Many Types of Radars Are There and What Are Their Uses in Aviation?

18/07/2025

In the world of aeronautics, new technologies are a key part of the industry’s evolution. New methods are constantly emerging to improve operational safety, and we often highlight them on this blog. However, it’s worth looking back at certain technologies that, although developed many years ago, remain cornerstones of our industry. One such technology is radar. Do you know how many types of radar exist and how they are used in aviation?

A Brief History of Radar

First, let’s explore what radar is, the technology behind it, and how it came to be. To understand its origins, we need to go back to 1886. That year, German physicist Heinrich Rudolf Hertz demonstrated that electromagnetic waves (which carry energy through space from one point to another) are reflected by metallic surfaces. This was the starting point for a system that would go on to revolutionize communications in the broadest sense (it’s no coincidence that the unit of frequency, the hertz, is named after him).

From that point, the development of an anti-collision system for ships using electromagnetic waves emerged in 1904. That same year, Marconi patented the radio—a technology largely attributed to Nikola Tesla, who also laid the groundwork for antenna technology and, in turn, early radar systems.

“Radar” is a lexicalized acronym for Radio Detection and Ranging. It marked the beginning of a new era in communications and transportation safety.

What Exactly Is Radar?

Radar is a system that uses pulses of radio waves (electromagnetic waves): it emits them and detects the signals that are reflected back from objects. In other words, it analyzes the echo of these bouncing waves to determine an object’s distance, speed, and direction.

Just like tuning a radio at home by adjusting the dial to the correct wavelength, different radar types operate within distinct radiofrequency spectrums. Let’s take a closer look.

Common Types of Radar Used in Aviation

With this understanding, it’s easy to imagine the wide range of uses radar has today. We see it daily on the roads, where it detects speeding vehicles, for example. Since its development—especially in the years leading up to World War II—its applications have expanded into many fields, most notably aviation.

ATC Radars (Air Traffic Control) is a broad term that encompasses all radar systems used in both civil and military air traffic control. As one would expect, these systems are highly sophisticated. Here are the most commonly used radar types in the aviation industry:

Air Surveillance Radar (TAR)

Found in airport control towers, this is an approach radar system. It detects approaching aircraft and determines their position. These radars operate in the E-band (part of the radiofrequency spectrum ranging from 2 to 4 gigahertz) and can track aircraft flying below 25,000 feet (approximately 7,600 meters) within a radius of up to 110 km (60 nautical miles).
Due to the need for constantly updated approach data at airports, these radar antennas rotate rapidly—up to 15 revolutions per minute.

Precision Approach Radar (PAR)

As the name suggests, this radar system manages aircraft during the final approach phase. Its precision enables pilots to navigate even under low-visibility conditions. A radar operator gathers the information and relays it to the pilot either via radio or a digital link. These systems operate in the X-band (approximately 8 to 12 gigahertz).

Surface Movement Radar (SMR)

Operating strictly within the airport environment, this radar monitors all movement areas including runways, taxiways, and aprons. The radar waves bounce off ground vehicles and transmit this data back to the radar antenna. SMR systems typically operate within the X to K bands (ranging from 8 to 27 gigahertz).

En-Route Radar

This radar type manages air traffic outside of the immediate airport environment. It operates in the D-band, which spans frequencies from 1 to 2 gigahertz. These radars detect the position, heading, and speed of aerial targets (including unmanned aerial vehicles) within a range of up to 450 kilometers.

Doppler Radar

Among its many uses, Doppler radar plays a vital role in meteorology—essential for the safety of all forms of transportation. These radars, often used by law enforcement to detect speeding vehicles, are typically installed onboard aircraft. They generate high-quality visual information, helping pilots identify nearby storm systems, precipitation, and the intensity of such weather phenomena.

Photo | deepblue4you

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