What Is Drone Radar? (AESA, SAR, GMTI)

The radars that see through clouds, track movement, and steer electronically

One of a drone's most valuable features may be its cameras, but its real strategic power often comes from a component you can't even see: radar. Cameras show you what's visible; radar lets you see through clouds, through night darkness, and detect movement kilometers away. In this post, we'll break down the three core radar technologies used in drones — SAR, GMTI, and AESA — in plain language, then take a look at systems Türkiye has developed in this space, such as SARPER, MİLSAR, and GÖKTÜRK-3.

Why can radar see things a camera can't?

A camera only works where there's light. Radar, on the other hand, sends out its own signal and listens for its return — so it doesn't need light at all. This means radar can operate in complete darkness, under thick cloud cover, and even through fog or rain. That's exactly why adding radar to a drone turns it into a platform that can operate "in any weather."

SAR: The camera that sees through clouds

SAR (Synthetic Aperture Radar) works by sending radar waves toward the ground and collecting the signals that bounce back, building a high-resolution image or map from them. Unlike a regular camera, it can work just as clearly in the dark or underneath cloud cover.

There's a small trick behind how SAR works: as the drone moves, it combines the signals it collects along the way, effectively behaving as if it had a much larger antenna than it actually does. This lets it capture sharp images — even of a small vehicle or a freshly made tire track — from hundreds of meters up.

In practice, SAR is used for things like:

  • 1Detecting a weapons depot or a newly constructed structure
  • 2Spotting small ground changes, such as a freshly dug trench or a new tire track
  • 3Getting reliable imagery even at night or in bad weather

GMTI: The observer that catches movement

If SAR takes a "photograph" of an area, GMTI (Ground Moving Target Indicator) tracks who's moving within it. It does this using a principle from physics called the Doppler effect: the signal reflected from a stationary object stays the same, while the signal from a moving object shifts in frequency. GMTI picks up on that shift, filters out the static terrain from the screen, and flags only what's moving — a truck, a vehicle, even a group of people on foot.

This isn't passive observation — it's an active "who's going where" kind of tracking. GMTI plays a critical role in spotting logistics movements or the early signs of a build-up before it happens.

AESA: Radar's electronic "eye"

Older radars had to physically rotate to look in a given direction — slow, and limited. AESA (Active Electronically Scanned Array) takes a completely different approach: its antenna is made up of hundreds, even thousands, of tiny transmitter modules. These modules can electronically steer the signal in any direction needed, without any physical part moving at all.

The advantages this brings:

  • Multi-tasking: It can capture imagery (SAR mode) and track moving targets (GMTI mode) at the same time.
  • Harder to detect: Because signals are spread across a wider frequency band, enemy radar detection systems have a harder time picking them up.
  • Durability: Even if one module fails, the system keeps working.
  • Speed: Electronic steering responds far faster than physically rotating ever could.

In short, AESA provides the flexible backbone that makes both SAR and GMTI possible.

Türkiye's solutions: SARPER and MİLSAR

Two notable systems stand out in this field from Türkiye: SARPER (ASELSAN) and MİLSAR (Meteksan). Both are capable of SAR and GMTI at the same time — meaning they can capture imagery and track moving targets simultaneously.

SARPER was designed specifically for light and medium-range drones, and was first integrated into the ANKA platform. Its ability to operate at altitudes up to 30,000 feet allows the drone to carry out missions from a safer distance, beyond the reach of enemy missile systems. It also outputs data compliant with NATO's STANAG 4607 standard, which makes data sharing with allied forces much easier.

MİLSAR, on the other hand, has mainly been integrated into larger, heavier drones like AKSUNGUR. Thanks to its dedicated maritime search mode, it can detect surface vessels — and even drifting mines — making it especially valuable for naval operations. Weighing under 30 kilograms, it can be easily integrated into a wide range of drone platforms.

One step beyond the sky: GÖKTÜRK-3

Türkiye's radar-based intelligence capacity doesn't stop at drones. GÖKTÜRK-3 is being developed as Türkiye's first military observation satellite equipped with SAR technology. The goal is to reduce reliance on satellite imagery from foreign providers and give Türkiye the ability to observe anywhere in the world, in any weather, day or night, using its own capacity.

While a drone's radar monitors a specific area closely and in real time, a satellite can track a much wider area over a much longer stretch of time. Put together, these two layers form a complementary surveillance network: drones deliver fast, detailed responses, while the satellite provides the bigger picture and reveals changes over time.

Key Takeaway

What these systems have in common is that Türkiye developed the radar technology equipping its drones largely on its own. This reduces external dependency while keeping the maintenance, development, and export potential of these technologies within the country. As AI-powered image analysis tools increasingly combine with this radar data, target detection and classification are expected to become faster and less prone to human error in the future.

Sources and Further Reading

Official Institutional Sources

ASELSAN Official Website — Radar Systems and MURAD AESA Radar
Meteksan Defense — MİLSAR SAR/MTI Radar System
TUSAŞ — GÖKTÜRK-3 Project
Presidency of Defense Industries (SSB) — GÖKTÜRK-3 Project Details
TÜBİTAK Space Technologies Research Institute — Satellite Projects

Technical Documents

Radartutorial.eu — SAR and AESA Radar Principles
NASA Earthdata — Synthetic Aperture Radar (SAR) Basics
A. Moreira et al. (2013), "A Tutorial on Synthetic Aperture Radar"
Northrop Grumman — Active Electronically Scanned Array (AESA) Radars
Millî Savunma Platform — SARPER and MİLSAR Technical Documents

Data Standards

STANAG 4607 — NATO Standard Imagery Format

Suggested Further Reading

"A Tutorial on Synthetic Aperture Radar" — A. Moreira (IEEE, 2013)
Capella Space & ICEYE — SAR Technology Basics guides
Defense Post & Bliley Technologies — AESA Radar articles
ASELSAN Magazine, Issue 120 (September 2024) — Radar Systems Special Issue