As drones become smaller and more widely used, detecting them in low-altitude airspace has become increasingly important. But how can radar detect a small drone flying at low altitude?

The answer lies in electromagnetic waves.

How Does Radar Detect a Drone?

Radar does not“see”a drone like a camera. Instead, it transmits electromagnetic waves into the surrounding airspace. When these waves encounter a drone, part of the energy is reflected back toward the radar.

The radar receives these echoes and analyzes them to determine whether a target is present. By processing the returned signals, radar can obtain information such as the target’s distance, direction, and speed.

The basic process is:

Transmit → Reflect → Receive → Analyze → Track

How Does Radar Know Where the Drone Is?

Radar determines the drone’s distance by measuring how long the electromagnetic wave takes to travel to the target and return. It can also determine the target’s direction through its antenna system.

Modern phased-array radar can electronically control its radar beam, allowing it to scan airspace rapidly and locate targets precisely.

How Does Radar Measure Drone Speed?

Radar can measure a drone’s movement through the Doppler effect. When a drone moves toward or away from the radar, the frequency of the reflected signal changes.

By analyzing this frequency shift, radar can estimate the drone’s radial velocity and continuously monitor its movement.

Why Is Small Drone Detection Challenging?

Small drones generally produce weaker radar echoes than large aircraft. At the same time, buildings, trees, vehicles, birds, and terrain can also create unwanted echoes, known as clutter.

Modern radar therefore uses technologies such as Digital Beamforming (DBF) and advanced signal processing to identify weak target signals while reducing the impact of clutter. Multi-target tracking also enables the radar to monitor several targets at the same time.

YFR-03: Low-Altitude Security Intelligent Detection System

YFR-03 combines microwave radar, DBF, mechanical scanning, and multi-target tracking for low-altitude security applications.

With a detection range of 6–100 km, depending on target RCS and operating conditions, YFR-03 can be used for critical area protection, counter-drone operations, and border security.

Supporting target velocities from 1–100 m/s, it can simultaneously detect and track multiple low-altitude targets, including drones and other Low, Slow, and Small (LSS) targets.

YFR-03 is available in X-band and Ku-band configurations. X-band offers a balance between detection range and environmental adaptability, while Ku-band provides higher angular resolution for precise detection and tracking of small targets.

By combining advanced radar technology with multi-target tracking, YFR-03 provides reliable situational awareness for modern low-altitude security applications.