Fraunhofer Institute for High Frequency Physics and Radar Techniques FHRDaily life on Earth increasingly depends on satellites for technical services. The growing amount of space debris threatens this critical infrastructure. To protect satellites from collisions, the position and velocity of space objects must be known. The space surveillance radar GESTRA (German Experimental Space Surveillance and Tracking Radar), developed at Fraunhofer FHR for the German Space Agency inside DLR, is an important partner here: it detects and tracks space debris objects to build a trajectory data catalog while also contributing to strong capability development in Germany’s space surveillance. For operators of critical satellite infrastructure, this means more safety, more predictability, and greater protection against failures.
Evolution with a new receiver and networking
With GESTRA EUSST (deployment of an additional receiving unit) and GESTRA Networking (development of algorithms and operations control software for networked systems), GESTRA is being expanded to improve object position determination in low Earth orbit. In principle, expanding the GESTRA system with additional similar receiving and transmitting units should further enhance the performance of the GESTRA sensor network. The following goals are intended to be achieved:
- Detection of smaller particles through the GESTRA system network
- Improvement of trajectory determination for objects
For active satellites, a collision with a particle of about 1 cm in diameter is considered critical. With the extended GESTRA architecture, we support operators in early risk identification and in making more informed operational decisions.
Stronger together: study confirms benefits of radar networks
To explore possible extensions, Fraunhofer FHR, in cooperation with Fraunhofer FKIE, conducted a study on the advantages of radar networks. The result: deploying multiple transmitters and receivers and networking them yields the greatest benefit with respect to the goals mentioned above. For GESTRA, the most efficient solution with the greatest added value was initially chosen to expand by an additional receiver. The findings of the study are used in the GESTRA EUSST and GESTRA Networking projects, where the concrete use cases are specified and adapted to real systems. In summary: with GESTRA EUSST, a partially mobile phased-array radar receiving system will emerge, operating in the L-band between 1280 and 1380 MHz, extending the lessons learned from the GESTRA system. This benefits operators with a scientifically grounded, technologically mature, and real-world-conditions-optimized solution.
Partially mobile system on a container basis
GESTRA EUSST is designed as a partially mobile, container-based system that includes all infrastructure such as climate control and power generation. Like GESTRA, this unit also features mechanical and electronic beamsteering through the 3D positioning unit or the digital beamformer. In the future, the EUSST receiver, together with the sensor unit developed in the GESTRA project (transmitter and receiver in networked operation), is intended to monitor low Earth orbit (100 km to 3000 km altitude). GESTRA Networking provides the required operating and data evaluation software. This creates a powerful overall system that actively supports operators of satellite fleets, space agencies, and security-critical infrastructures in collision avoidance. Together, these projects will ensure increasingly accurate tracking of space debris in the future.