Experimental Systems

The large radar system TIRA serves as an experimental sensor for monitoring near‑Earth and geostationary orbit and provides highly precise tracking and imaging data for national and international partners. As a central research instrument at Fraunhofer FHR, TIRA supports the development of advanced radar techniques for detecting, tracking, and characterizing objects in space. The data it generates form a key basis for re‑entry predictions, collision avoidance, fragmentation analyses, and operational decision‑making at the German Space Situational Awareness Center. The system combines an L‑band tracking radar with a broadband Ku‑band imaging radar, enabling the determination of orbital parameters, motion, size, shape, and material properties—even for small objects. Continuous modernization efforts—including new drive systems, a renewed radome, and the development of a high‑resolution polarimetric imaging radar—ensure that TIRA remains at the forefront of technology and provides a foundation for future scientific and operational applications.

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• TIRA

The space surveillance radar GESTRA enables systematic monitoring of large orbital volumes in low Earth orbit and provides precise orbital data to the Space Situational Awareness Center operated by DLR and the German Armed Forces. The semi‑mobile system detects and tracks satellites, debris fragments, and small objects, making a significant contribution to assessing potential collision risks. During a 2023 capability demonstration, GESTRA detected an average of more than 200 objects per hour, including small satellites at altitudes of several hundred kilometers. After successful calibration, GESTRA has been part of the European Space Surveillance and Tracking (EU SST) program since 2024 and delivers up to 13,000 tracks per day. Its phased‑array technology with 256 individual elements enables highly flexible, real‑time beam steering, supported by mechanically adjustable antennas. With the projects GESTRA‑EUSST, GESTRA‑Networking, and GESTRA‑TX2, the system is currently being expanded to further increase resolution and overall performance.

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• GESTRA

Realistic airborne testing requires flexible and precisely controlled experimental conditions. The Fraunhofer FHR drone platform provides a versatile environment in which drones can be deployed both as sensor carriers and as defined targets with configurable radar signatures. This enables the creation of realistic scenarios for the evaluation, validation, and optimization of advanced sensor technologies and system solutions. The integrated sensor suite—including radar, lidar, cameras, and ultrasonic systems—supports the development of complex systems and innovative applications. High-precision positioning based on Global Positioning System data with real-time kinematic correction (GPS‑RTK) allows accurate tracking of flight trajectories and ensures reliable analysis of measurement data. This provides a robust foundation for applications such as drone detection as well as automated flight and landing procedures.

Use Case Example

• UAV Rescue

As a standalone millimeter-wave imaging system, SAMMI 3.1 enables precise inspection of a wide variety of materials—completely contactless and without the use of ionizing radiation. The system penetrates electrically non-conductive materials such as plastics, wood, or glass and generates high-resolution 3D synthetic aperture radar (SAR) images in real time, including both amplitude and phase information.

This makes it possible to visualize internal structures without damaging the object under test. Owing to its reflective measurement principle, SAMMI 3.1 is also suitable for inline operation and can be directly integrated into industrial processes. Typical applications range from non-destructive testing and material analysis to quality control and even use as a mail scanner in postal facilities.

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• SAMMI 3.1

Our modular 3D scanner is a flexibly configurable radar imaging system that enables full 3D measurements using synthetic aperture radar (SAR), supported by precision linear stages and a rotating turntable. Its wide frequency range, spanning from 1 GHz to 240 GHz, provides either high-resolution surface profiles or insights into internal structures, depending on the material properties and system configuration.

The system has demonstrated its performance in numerous scientific and industrial applications, delivering robust datasets for process monitoring, material characterization, and quality assessment. Owing to its modular architecture, it can be precisely tailored to specific requirements and supports a broad spectrum of use cases—from non-destructive testing and materials research to automotive engineering, medical technology, and quality assurance, as well as applications in food and agricultural technology and security inspection.

Use Case Example

• AFARA

Our reflector-based receiving systems enable highly sensitive and directional signal reception in the L- and X-band frequency ranges. Equipped with parabolic reflectors (including multifeed capability in the L-band) and high-precision positioning systems, they capture signals from aircraft and satellites with high spatial accuracy. Integrated precision timing sources allow for exact time synchronization of the data, while the highly focused antenna beam enables reliable tracking of known flight trajectories. The systems provide precise reference data for measurement campaigns and experimental setups, support the validation of phased-array radar systems, and—thanks to their high directivity—are particularly well suited for ground-based airspace and orbital surveillance applications.

Use Case Example

• GESTRA-Space Surveillance wiht Radar Networks

LIRIS (Linear Radar Imaging System) is a high-resolution radar scanning system operating in the D-band (120–170 GHz) for contactless and non-destructive testing of materials. It enables detailed imaging analyses, particularly for electrically non-conductive materials such as plastics, ceramics, and composite structures. Even very small impurities, air inclusions, or delaminations within the material can be reliably detected—especially in cases where optical methods reach their limits. Owing to its inline capability, LIRIS is ideally suited for industrial quality control and sorting processes, for example in the detection of hard-to-identify black plastics. The system thus provides a powerful solution for modern production environments and demanding inspection tasks in both industry and research.

Use Case Example

• Waste4Future

The airborne radar system MIRANDA‑35 is a high-performance synthetic aperture radar (SAR) system operating in the 35 GHz frequency range. It enables highly precise imaging with a range resolution of up to 10 centimeters. With a bandwidth of 1.5 GHz, it delivers detailed radar imagery independent of weather and lighting conditions. This makes MIRANDA‑35 particularly well suited for demanding airborne reconnaissance and surveillance missions. Funded by armasuisse, the system is part of international research collaborations, including close cooperation with Armasuisse and the University of Zurich. Thanks to its high reliability and operational flexibility, MIRANDA‑35 makes a significant contribution to the advancement of modern airborne sensor systems.

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• German-Suisse Cooperation with Armasuisse and University of Zürich

Phoenix‑94 is a drone-mounted synthetic aperture radar (SAR) system operating in the 94 GHz frequency range, combining high resolution with maximum operational flexibility. With a bandwidth of 3 GHz, the system achieves a range resolution of approximately 5 centimeters and delivers highly detailed radar imagery from a wide variety of perspectives. Its integration on unmanned platforms makes Phoenix‑94 particularly well suited for mobile and rapidly deployable reconnaissance missions. The system has been successfully validated in international measurement campaigns, including within the NATO SET‑317 initiative, and was part of the SCOUT25 technology demonstration in Switzerland. Phoenix‑94 thus represents a prime example of modern, agile radar technology for airborne applications. 

Use Case Example

• Radar Systems from Fraunhofer FHR Support NATO Measurement Campaign

MIRANDA‑94 is a state-of-the-art synthetic aperture radar (SAR) system operating in the 94 GHz frequency range. With a bandwidth of 4 GHz, it achieves an exceptional range resolution of up to 4 centimeters. An integrated gimbal system stabilizes the radar and compensates for aircraft motion, enabling the acquisition of precise image data even during demanding flight maneuvers such as circular SAR operations.

The system is ideally suited for high-resolution reconnaissance and surveillance missions and opens up new possibilities in airborne remote sensing. MIRANDA‑94 is deployed, among others, in future-oriented programs such as FCAS and supports the development of innovative sensor solutions for complex operational scenarios.

The drone-mounted SAR system Phoenix‑35 operates in the 35 GHz frequency range and, with a bandwidth of 1.5 GHz, achieves a range resolution of approximately 10 centimeters. It combines a compact design with ease of integration into UAV platforms and delivers reliable imaging performance even under challenging operational conditions. Phoenix‑35 is particularly well suited for flexible surveillance and reconnaissance missions where mobility and rapid deployment are critical. Funded by Armasuisse, the system is used in German-Swiss collaborative projects and supports the development of new applications in the field of airborne radar sensing. With its balanced combination of performance and flexibility, Phoenix‑35 represents a versatile tool for modern remote sensing.

Use Case Example

• German-Suisse Cooperation with Armasuisse