Projects

You know it from driving: when you pass an object, you only get a relatively fleeting glimpse. If you circle around the object, you can view it from all sides. The same applies to radar imaging. Typically, SAR is flown with an aircraft in a straight line over the object and radar data are collected during that pass. With circular SAR, the aircraft flies circular orbits over the area to be observed. While this makes signal processing more challenging, it provides a significantly expanded data base because a given area can be illuminated over a long period — and as with radar, independent of time of day and weather.

The field‑of‑view range of phased array antennas is inherently limited by physical constraints. Through the use of electronically tunable metamaterials, this range could be expanded in the long term, thereby enabling new application possibilities

Radar is the most important sensor for autonomous driving. A hHigh spatial resolution is achieved, according to the multiple-input/multiple-output (MIMO) principle, by a large number of antennas, each connected to individual gates ports of integrated radar ICs. When designing the complex high-frequency interconnect networks, the previously used printed circuit board technologies reach their limits.

Future-proof space situational awareness with radar: Fraunhofer FHR has further developed the signal processing systems of the target-tracking radar at the TIRA large-scale radar facility, thereby significantly expanding the capabilities of radar-based space observation. A special target was chosen for the first experiments with the new instrument: the Moon. The result is a high-resolution radar image of the entire lunar surface visible from Earth.

TIRA-Digital modernizes the signal processing of the L-band target-tracking radar of the space surveillance radar TIRA. Through an innovative, software-based architecture, radar signals are digitized directly at the antenna and processed in real time. The obtained data underpin forecasts, warnings, and analyses for national and European space infrastructure and strengthen Germany’s sovereignty in space intelligence. Thus, TIRA Digital creates a future-proof foundation for reliable decision-making and the safe operation of orbital systems.

Fraunhofer FHR is equipped with a variety of instruments and facilities to perform numerous types of RF measurements. This includes the characterization of antennas and RF circuits, monostatic radar cross section (RCS), and measurements of electromagnetic material parameters. In addition to standard procedures, customized measurement solutions can also be developed. Our in-house precision mechanics workshops provide valuable support.

In the deployment of airborne radar systems, a central objective is to obtain results of the highest possible precision in the detection and classification of objects on the ground. Research conducted at Fraunhofer FHR has demonstrated that multidimensional radar imaging can provide valuable additional information about a scene. The institute addresses this topic on behalf of the German Armed Forces and actively contributes to relevant NATO research groups.

Hypersonic weapons have now become part of numerous international weapons systems and represent a growing security policy challenge for Europe as well. Against this background, Fraunhofer FHR is working on the further development of radar-based detection and defense methods and, within the framework of the HypS²tar (Hypersonic Signature Studies for Radar) research initiative, is investigating the interactions between radar waves and plasma-physical effects during hypersonic flight.

Cognitive radar systems respond to their environment and adjust their parameters in real time. Fraunhofer FHR is contributing to the development of a demonstrator with space-capable hardware that is intended to illustrate these capabilities. The institute provides a pre-trained neural network as well as decision criteria to detect and avoid disturbances in a radar signal before the SAR (Synthetic Aperture Radar) image is captured. SAR satellites deliver high-resolution images of the Earth's surface day and night. So far, raw data are mostly transmitted to Earth and processed and analyzed on the ground with classical algorithms.

High‑resolution imaging despite the simultaneous motion of both the sensor platform and the target scene, combined with rapid changes in viewing direction—this is the performance profile envisioned for a novel airborne radar system. An eagle possesses an exceptionally high visual acuity and can precisely detect and interpret ground structures even while in flight. Researchers at Fraunhofer FHR are working to replicate this capability technologically: a radar system mounted on an aircraft that provides an electronically steerable, highly agile field of view. The viewing angle is intended to be redirected toward relevant scenarios within extremely short time intervals. Which scenarios are considered relevant will in the future be determined by a specially developed processing and decision‑making algorithm.