Defense

Air space surveillance and radar imaging for remote reconnaissance

The radar systems developed in the Business Unit Defense monitor airspace from the ground – the radar systems look from the ground into the air. Attached to aircraft or satellites, radar systems monitor air, sea and land areas. Using remote imaging reconnaissance, buildings and other static objects can be surveyed, as can moving objects such as cars. Target classes are also detected: In the air helicopters, missiles and the like are distinguished; on the ground, vehicle classes can be recognized, for example. A general trend that is starting to emerge in the radar field: The use of higher frequencies is increasing. This means that smaller and lighter radar systems can be realized, and the increasing use of mobile communications and WLAN is also making the current frequency range more constricted. With its 300-gigahertz radar, the Business Unit Defense is in the big league on an international level.

Further radar developments for defense

Radar is also a practical solution for some close range issues: It can be important on drones or other unmanned aerial objects, as well as on robots or on vehicles. On military vehicles, it is possible to recognize when the vehicle is being fired on: For example, if a grenade is approaching, the hundredths of a second are crucial to initiate active protection measures.

If another country wants to reconnoiter the conditions in this country, this is by no means welcome. For this reason, the Business Unit Defense is working on deceiving and jamming radar systems with the corresponding transmitters – to impede or prevent any exploration by this means. Passive radar is an ideal solution to conceal one’s own observation and to thus protect against these types of jamming attempts. This involves not transmitting the signals oneself, but using the radio waves of others to monitor the airspace – in such a way that one does not make oneself noticed. The market launch of such a system for monitoring the airspace of wind turbines in the Business Unit Human and Environment was successful.

Cognitive radar is still a rather new field of research for the Business Unit Defense. Achieving the optimum setting of a radar system for its use is usually a complex challenge. In the future, the radar will use its own intelligence to set its own parameters and adapt them optimally to the task. After all, it makes a big difference whether radar images are to be taken of areas with high mountains or over the sea with strong waves. Good results have already been achieved in the field of such a cognitive radar, which have also been transferred to industry. Fraunhofer FHR is also already applying its accumulated know-how in the still quite fresh research field of metamaterial design in initial projects for targeted radar backscatter reduction.