Space: Precise detection of the position of object

It is not only on roads in metropolitan areas that traffic density is high. Low-Earth orbit is also very busy and sometimes crowded: It is littered with active satellites as well as space debris – their density is increasing rapidly.

This rush hour in space is accompanied by increasing hazards: collisions can destroy satellites and affect infrastructure that is important to society (e.g., navigation or communication satellites). It is therefore essential to detect, monitor and track space objects: If these are always in view, countermeasures can be initiated in good time in the event of imminent danger, such as evasive maneuvers by satellites.

GESTRA and TIRA: Hand in Hand

The radar systems researched and developed by Fraunhofer FHR’s Business Unit Space are ideally suited for monitoring, observing and identifying objects in low-Earth orbit. In this context, the two radar systems TIRA and GESTRA complement each other perfectly. The GESTRA radar system, which was developed on behalf of the German Space Agency at DLR (German Aerospace Center), allows continuous monitoring in wide-range space – it can be used to determine the orbital data of many objects simultaneously. In addition, GESTRA can be used to determine the altitude of objects as well as their inclination – the degree between the Earth’s equator and their orbit. Another special feature: GESTRA combines phased array antennas, mechanical mobility of the radar units in three axes, and mobility of the entire system. GESTRA can thus be deployed at any location, enabling a network of radar systems for space surveillance.

If, on the other hand, a specific satellite or other space object needs to be detected more precisely, TIRA is the system of choice. It allows satellites to be detected and imaged with much greater precision – and additionally enables statements to be made about the satellite itself. If a satellite is not working, for example, TIRA can be used to clarify whether this may be due to the solar panel not being deployed correctly. The ability to image space objects in high definition using TIRA is unique in Europe, which is why the system has already supported numerous missions.

To date, the Business Unit Space has been focusing on the space situational awareness of space objects. The plan is to expand Earth-based SSA sensors to include a space-based radar. In this case, the radar system that observes the space objects is no longer located on Earth, rather on a satellite in orbit. The portfolio is also to be expanded with the inclusion of other research topics such as active antenna technologies for communications satellites, SAR (Synthetic Aperture Radar) technology for Earth observation satellites and satellite-based microwave radiometers for climate and environmental research. The Business Unit Space will therefore be even more broadly positioned – the major competencies will then also benefit other space research fields.

Technical contributions from the business unit

»Baptism of fire« of the space surveillance radar GESTRA

Christoph Reising


The search for the needle in the haystack

Jeremias Schroer, M. Sc.


High-resolution imaging radar for space observation

Dr. rer. nat. Jens Klare


Garbage collection for orbit

Frank Schlichthaber


My house, my car, my space surveillance radar?

Christoph Reising


Radar networks in practice: GESTRA meets EUSST

Dipl.-Ing. Markus Gilles


Space surveillance using radar networks

Rudolf Hoffmann

Pioneering work in commercialization

Dipl.-Ing. (FH), BW Markus Postma

Higher sensitivity with deep-frozen radar receivers

Dipl.-Ing. (FH) Andreas Fröhlich


Future TIRA – space observation radar of the future

Dr. rer. nat. Jens Klare


GESTRA Milestones 2020

Dipl.-Ing. Helmut Wilden


Retrieving space debris: The space observation radar TIRA can provide support

M. Sc. Nora Egli

GESTRA: low Earth orbit always »in sight«

Dipl.-Ing. Helmut Wilden


Space Debris Under the spotlight: High-precision orbit determination with TIRA

Dr. rer. nat. Jens Klare


Sharper ISAR images of satellites and other space objects

Dr.-Ing. Delphine Cerutti-Maori

Detect space debris better with higher transmitting power

Christoph Reising

Despite all expectations

Dipl. Phys. Frank Schlichthaber