Artillery locating radar

Artillery locating radars work by emitting a narrow beam of radio waves and detecting the echoes from incoming projectiles. By measuring the projectile's trajectory at multiple points, the radar computes its ballistic path and extrapolates backward to determine the launch point. This process, known as back-tracking or inverse trajectory analysis, relies on precise Doppler and angle measurements.¹

Modern systems use phased-array antennas that can electronically steer the beam in milliseconds, allowing them to track multiple targets simultaneously. The radar typically operates in a search mode to acquire targets, then switches to track mode to refine the trajectory. The computed origin is displayed on a tactical map, often with a confidence ellipse indicating the likely error area.²

The concept emerged during World War II, when the British developed the GL Mk. II radar for gun-laying, but the first dedicated artillery locating radar was the US AN/MPQ-10, introduced in the 1950s.³ It used a parabolic reflector and could locate mortars within a few hundred meters.

The Vietnam War spurred advances, as the US Army deployed the AN/TPQ-31 and later the AN/TPQ-36 and AN/TPQ-37 Firefinder radars. These systems used phased-array technology and could locate artillery at ranges up to 50 km.⁴ The Soviet Union developed analogous systems like the ARKS-1 and Zoopark-1.

Contemporary artillery locating radars, such as the US AN/TPQ-53 and the Swedish Arthur (Artillery Hunting Radar), offer high mobility and rapid deployment. The AN/TPQ-53 can detect rockets, artillery, and mortars simultaneously, and its active electronically scanned array (AESA) provides a 90-degree coverage that can be rotated 360 degrees.

These systems integrate with fire control networks, automatically transmitting target coordinates to counter-battery assets. The Arthur system, developed by Saab, is used by several NATO countries and has a reported accuracy of 0.2% of range. Other notable systems include the Chinese SLC-2 and the Indian Swathi.

Artillery locating radars are vulnerable to electronic warfare, including jamming and deception. Some artillery projectiles are designed with reduced radar cross-section, and rocket-assisted projectiles can alter trajectory unpredictably.⁵ Additionally, the radar's own emissions can be detected by enemy ESM (electronic support measures), making it a target for anti-radiation missiles.

To mitigate these risks, modern systems employ frequency hopping, low probability of intercept (LPI) techniques, and rapid relocation after firing. The AN/TPQ-53 can be set up and taken down in under five minutes.

One obscure fact is that the first practical artillery locating radar was developed by the British during World War II, but it was not widely used until the Korean War.³ Another is that the AN/TPQ-36 was initially designed to locate mortars, but its software was later upgraded to handle rockets and artillery.

In the 1980s, the Soviet Union deployed the Zoopark-1, which used a passive phased-array and could locate up to 100 targets per minute. A niche application is the use of artillery locating radar in civilian contexts, such as detecting illegal mining explosions or monitoring volcanic eruptions, though these are experimental.⁶

Counter-battery fire

Fire directed at enemy artillery to destroy or neutralize it.

Phased-array antenna

An antenna with multiple elements that can steer the beam electronically without moving.

Back-tracking

The process of computing a projectile's origin from its observed trajectory.

Circular error probable (CEP)

A measure of accuracy; the radius of a circle within which 50% of rounds land.