Fraunhofer Institute for High Frequency Physics and Radar Techniques FHRIn Wachtberg near Bonn, Fraunhofer FHR operates the TIRA (Tracking and Imaging Radar) as an experimental sensor for space surveillance for the Federal Ministry of Defence and the Federal Republic of Germany. With its comprehensive capabilities for space situational awareness via radar, TIRA makes an important contribution to protecting national infrastructure in space. TIRA also provides mission support for international space organizations and satellite operators.
Comprehensive space situational awareness through radar technology
TIRA serves primarily as an experimental platform for developing and researching radar methods to detect and characterize objects in space. The data and insights gained from TIRA observations form, among other things, the basis for re-entry predictions (as demonstrated most recently with the ISS battery pack), conjunction assessments, analysis of fragmentation events, and support for on-orbit removal of satellites as well as missions for active disposal of space debris. In this way, they help ensure the safety and stability of our national space infrastructure in projects conducted with partners such as the Space Command (WRKdoBw) and the joint space situational awareness center of the Bundeswehr (WRLageZ), the German Aerospace Center (DLR), and the European Space Agency (ESA). Space agencies from around the world also rely on TIRA’s capabilities.
High-precision radar data for time-critical space applications
The space surveillance radar possesses globally unique capabilities outside the USA: ground-based, high-precision orbit and imaging data for objects in space, including estimates of orbital parameters, intrinsic motion, lifespan, size, shape, mass, and material properties. Applications range from precise mapping of space debris to avoidance maneuvers and imaging of out-of-control objects. Especially in time-critical situations, TIRA provides quickly available, robust data that directly support operational decisions. The combination of narrowband tracking, high coherence, and broadband imaging makes TIRA a powerful instrument for fundamental research as well as for operational space surveillance.
Pace-setter capabilities
With the growing use of space for military and civilian applications at high density and including increasingly smaller satellites, new research topics emerge. To address these challenges, Fraunhofer TIRA researchers continuously advance their work. In recent years, the drive systems of the fully movable Azimuth-Elevation Cassegrain antenna, the transmitter of the tracking radar, and the overall radome protecting the facility have been completely renewed.
Currently, radar instruments for target tracking and target imaging are in the focus of development. TIRA’s sensitive pulse-Doppler tracking radar in the L-band, with its monopulse system, is used to address research questions on detection, discrimination, precise orbit tracking, and orbital determination of satellites and space debris in low Earth orbit (LEO) up to geostationary orbit (GEO) for objects with diameters of a few centimeters. The highly dynamic antenna enables nearly seamless target tracking across the horizon plane of visible orbital segments.
In addition, Fraunhofer FHR researchers are working on developing a new, high-resolution, polarimetric imaging radar for TIRA that can accurately image ever-smaller satellites and their appendages. These modernizations not only secure the system’s performance but also create the foundation for future operational and scientific applications.