Research for protection

In the German Bight, the ELO project is now intended as the first major step toward protecting the infrastructure. The project is working to develop real-time capabilities for assessing the situation on the ground during maritime emergencies. Images and videos from various sources, including drones, are being used to do this.

This technology is designed to help salvage ships that have run aground or been involved in accidents, but even more, it will also contribute to protecting critical infrastructure points such as harbors and offshore wind farms against illegal activity like sabotage, allowing for early detection of threats and initiation of countermeasures.

The offshore drone campus operated by the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Cuxhaven is involved in the ELO project. Kai Brune and his team are responsible for integrating drone systems into the situation center’s operations concept and for automatically generating image and video materials in the German Bight. Transferring smooth, high-resolution images from a moving drone many kilometers away to screens at the situation center is a huge challenge.  

As the aircraft for use over the North Sea, the researchers use the S360Mk.II manufactured by project partner Hanseatic Aviation Solutions. Its wingspan of 3.6 meters makes this fixedwing drone perfect for use over the open sea. “We have already carried out several successful flights to Helgoland and back using this system,” Brune says, pleased.

When it comes to getting drones ready for challenging flights over the North and Baltic Seas, Fraunhofer IFAM is one of the top partners in Europe. In addition to the location in Cuxhaven, the institute operates the Test Center for Maritime Technologies on the island of Helgoland in partnership with the German Research Center for Artificial Intelligence (DFKI). The center’s activities include testing drone technologies for use under extreme offshore conditions.

As soon as a threat to critical infrastructure on the sea floor emerges, it is important to be present there as well with mobile systems. The situation calls for uncrewed underwater vehicles with powerful sensors, long-lasting batteries and AI controls. They need to be rugged enough to go about their dangerous business even at depths as great as 1,000 meters. The Advanced Systems Technology branch AST of the Fraunhofer Institute for Optronics, System Technologies and Image Exploitation IOSB in Ilmenau provides a research platform for this. A test pool affords the opportunity to develop and test hardware and software for underwater vehicles and components. A pressure test unit tests component assemblies to ensure that they are well sealed and stable.

Drone expertise also includes knowing how to detect and protect against them when they enter the areas around military sites, airports or power plants without authorization. So far, this has been done with radar systems or cameras. These systems are technologically complex and require a lot of energy, plus radar is easily detectable by the radio waves it emits. Radar systems also cannot be operated in densely populated urban areas or near hospitals or residential buildings due to harmful electromagnetic emissions.

Christian Steffes from the Fraunhofer Institute for Communication, Information Processing and Ergonomics FKIE has a solution: passive radar. These kinds of systems do not emit any radiation themselves. Instead, they harness the fact that flying objects also reflect mobile communication signals. Passive radar can use differences between the direct signals emitted by the mobile phone base station and the waves bouncing off the object to calculate values such as distance, direction of movement and speed. This technology does not rely exclusively on publicly accessible cell phone networks but also on LTE 450, a mobile communication standard developed specifically for secure communication for operators of critical infrastructure. It is especially robust, with special failsafes.

But there is a catch, of course. “Passive radar is not as accurate as conventional radar systems,” Steffes says. “But once a single drone or a drone swarm has been detected and further intel is needed, we use additional sensors such as cameras or active radar.” To do this, Fraunhofer FKIE has developed a fusion engine that combines and analyzes the full range of sensor data. These kinds of multi-sensor systems are increasingly playing an important role in security and defense technologies.

Werner Riedel holds the title of Chief Scientist Defense at the Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institut, EMI and is also an honorary professor at Furtwangen University and a visiting professor at Nanyang Technological University (NTU), one of Singapore’s top universities. He also has decades of experience in civilian and military security research at the EU level.

Riedel welcomes the focus on drone technology. “Drones will be critically important to scenarios in defense and security over the next few years. Here in Germany and across Europe, we need to intensify our research on further development and integration if we are to keep up in this arena.”

The Fraunhofer Institute for Applied Optics and Precision Engineering IOF is developing a technology to neutralize drones. The team of researchers is working with laser technology at a wavelength of two micrometers. High-performance lasers capable of hitting objects at distances of many kilometers have used the one-micrometer wavelength so far. However, at this range, not only the laser beam itself but also the laser light reflecting off of objects is harmful to people’s eyes, so these systems are not permitted in densely populated areas.

By contrast, the radiation scattered when a two-micrometer laser is used is absorbed by water, including by the human cornea, which is moist. This makes it significantly less of a risk to people’s eyes. To generate this wavelength, the Fraunhofer researchers added thulium, a rare earth, to optical fibers and developed a special lens. Three laser beams are passed through a diffraction grating that combines them into one. This is also made possible by improved methods for cooling the lasers. At the same time, the grating reflects more than 99 percent of the laser light, so it does not heat up as much.

Thomas Schreiber, head of the Laser and Fiber Technology department at Fraunhofer IOF, comments: “Because of the precision effects of the laser beam, we can use it like a scalpel. It has a diameter of about one centimeter at a distance of one kilometer, so with an approaching drone, you could point it directly at the control electronics.” German navy frigates could also use the high-performance laser to defend themselves against approaching flying objects. One advantage is that the laser does not require any ammunition that needs to be stored and replenished. 

When smart defensive systems go toe to toe against smart drones or drone swarms, there are certain positives as well. After all, no one gets hurt at first when machines fight machines.

However, in the world of AI, software and autonomous systems, threat scenarios are growing more complex. Meaning that hybrid threats are on the rise. Hans Peter Stuch, who leads a research group at the Fraunhofer Institute for Communication, Information Processing and Ergonomics FKIE, does not like the word “hybrid.” “It’s overused. True hybrid attacks are coordinated attacks originating from different domains.” For example, there might be a wave of social media posts criticizing the railway operator. Meanwhile, a cyberattack targets a signal box. And unknown parties attack a power line. Each of these attacks seems to be a minor annoyance in its specific domain, like a bee sting, but together, they add up to a significant threat or do huge amounts of damage.

To counter threats of this kind, the team at Fraunhofer FKIE is working on a system that collects information from different domains, including data from physical sensors such as surveillance cameras or radio receivers and from software tools that log malware attacks in the network. There are also structures in place to monitor social media for patterns such as a sudden spike in certain keywords. All of this information is combined to produce a visualization of the situation. This big-picture view makes it possible to see that the different events taking place in different domains are in fact connected, even if they occur with long gaps in between.  

To help those responsible for security respond appropriately when faced with a cyberattack, the experts at Fraunhofer FKIE offer regular security training sessions. Their main customers are energy suppliers and grid operators, and interest has been growing in recent years. “In many cases, we see that communication and coordination are the issue. Unclear responsibilities are a risk factor, too,” explains Martin Serror, who works as a cybersecurity instructor himself. “Knowing that, we put communication and coordination front and center in our training courses. We offer a true-to-life simulation environment tailored to the specific customer. Typically, we have participants go about routine tasks before facing a sudden cyberattack.”

The HERAKLION project, which is being supported by the German Federal Ministry of Research, Technology and Space (BMFTR), aims to develop heuristic resilience analyses for municipalities using data space functionalities. It might sound like an abstract scientific study, but this can actually save lives. “Take catastrophic flooding, for example. Thanks to HERAKLION, first responders know ahead of time which detours to take because other roads are washed out, how many people, buildings and critical infrastructure points are affected and which gyms and similar facilities are accessible for evacuees,” says Kai Fischer, manager of the Robustness and Resilience Analysis group at Fraunhofer EMI.

To gather the information needed for this, HERAKLION efficiently combines data from different sources: population structure, weather, forest fire risk, maps of areas at risk of flooding or heavy precipitation and much more. For maximum real-world utility in the way the information from the data analyses is displayed on the dashboard, the developers worked with disaster preparedness groups and first response planners right from the start. 

Riedel, an expert in this field, sees the lines between civil defense and defense technology becoming increasingly blurred: “The distinction was always a bit artificial. Resilient infrastructure, protecting the civilian populace and defense ultimately deal with many of the same topics, structures and capabilities.”

Schweitzer, the managing director of Fraunhofer VVS, adds: “Handled responsibly, civil and defense research both benefit society as a whole. At the same time, they both help with efficient use of financial resources.”

One good example of civilian technology being used for military benefit is RISK.twin. This joint project being conducted by the Fraunhofer Institute for Experimental Software Engineering IESE, the University of the Bundeswehr in Munich and software company NetApp, aims to generate digital twins of bridges and highway overpasses to enable smart maintenance management.

The structures are equipped with sensors to detect values such as vibrations, expansion and temperature. Together with the base data on the specific structure, this makes it possible to gauge capacity utilization and load-bearing capacity. The sensor data can even be updated hourly on a dashboard at a situation center. NATO troops moving around Germany in a defense operation could use this information to better plan their routes. After all, military vehicles are often on the heavy side, so the functionality and load-bearing capacity of structures like these are important pieces of information. The sensors installed on bridges that have been damaged in attacks provide information on the maximum weight they can still bear without risk.

Beyond smart sensors, software tools and dashboards, a research organization like the Fraunhofer-Gesellschaft can make even more of a contribution to future safety, Riedel points out: “Thanks to our insight into cutting-edge research, we can explore which technological topics will be relevant a few years down the line and also see where there are gaps in industry projects. And then we can zero in on those gaps with our pre-competitive research, such as dissertation topics. This approach also distinguishes the innovative strength and creativity of Fraunhofer researchers.”

Right now, hypersonic weapons are one of the biggest unanswered questions in defense. Hypersonic flying objects move at speeds of Mach 5 or more, faster than 1700 meters per second. They are not only fast but can also fly low to the ground and are extremely maneuverable. So far, defending against these objects has been very difficult. That is because in the hypersonic realm, everything changes: fuel, airworthiness, materials, aerodynamics, sensors, navigation — everything has to be rethought. For example, the control electronics get very hot, with friction heat reaching temperatures as high as 3,000 degrees Celsius. The plasma that forms on the object’s surface also adversely affects radar signatures.

When it comes to how to track and defend against these objects nonetheless, Daniel O’Hagan has answers. His résumé is very impressive. He wrote his dissertation on radar technology and currently works as a research scientist at the Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR, is the chief scientist and coordinator for hypersonic technology at Fraunhofer VVS and Chair of NATO TG SET 296 Radar Against Hypersonic Threats. In cooperation with the Bundeswehr, he has also established an international workshop on the topic. His calendar has always been packed, but it is even more so now, since the start of the war in Ukraine and since Russia began using hypersonic weapons.

O’Hagan places his hopes in a multi-layered multi-sensor system to defend against hypersonic missiles, linking radar sensors and electro-optical and infrared cameras (EO/IR) together. One key element of early warning is Skywave over-the-horizon radar (OTHR). Because they can fly low to the ground, hypersonic weapons are late in appearing over the horizon, where they become visible to traditional radar systems. At such high speeds, this leaves little time to respond. Over-the-horizon systems take advantage of the fact that radar at wavelengths of between three and 30 megahertz is reflected by the earth’s ionosphere, which “illuminates” even areas beyond the horizon. By registering the reflected waves, these systems can even detect objects that are actually flying outside the direct radar range.

“No system on its own can cover all the functions needed to detect and track hypersonic flying objects,” O’Hagan says, tempering expectations. “Much like with drones, the key lies in combining different technologies, for example in the interaction of satellite monitoring with various ground-based and airborne radar systems.” The Fraunhofer researchers view these technologies for civil defense, critical infrastructure and defense as more than just a technological challenge. They are also a social responsibility. As Steffes puts it: “We need to reassure people in Germany and elsewhere in Europe that we can respond swiftly and effectively in a crisis. And that will dispel the sense of uncertainty as well.” Once that is achieved, people setting off into the North Sea by boat can do so secure in the knowledge that the cables and pipelines on the sea floor are well protected.