An Interview with Weibel Doppler Radars

An Interview with Richard Engelholm, Business Development, Weibel

Explain a little about your role at Weibel Scientific.

My name is Richard Engelholm, and I work with Business Development in Weibel. Basically, I strive to identify companies, agencies and authorities that would benefit from our XENTA long-range drone surveillance radar. However, since I’m not a sales guy I don’t have the obligation of insisting that our product solves all of your problems. I have the privilege and time to dive into the counter drone realm and get to know all about the challenges, friction and pitfalls, and I have the freedom to share that knowledge with stakeholders looking to engage in counter drone solutions.

Describe how different stakeholders from various parts of the critical infrastructure sector perceive the current and future threat of drones.

The future proliferated drone threat can be described in two different axis. One axis constitutes the responsible end-user, e.g. private corporations vs. governmental institutions. To the first category, the threat is first and foremost a commercial threat where drones interrupt the operational stability, where the governmental institutions will be oriented towards their responsibility to protect their citizens. Both directly by ensuring safe daily lives in and around crowded areas and events, and indirectly by protecting e.g. parliaments, heads of states and law enforcement facilities from drone attacks.

The other axis constitutes the addressed drone threat that overall can be divided into non-hostile and hostile drones. Off course, a drone is not hostile in itself – it is merely a tool to carry out hostilities, sometimes operated by a pilot and sometimes pre-programmed for autonomous flight.

These two axis put together result in four ring corners where end-user motivation, responsibility, cost level and acceptable tolerances are variables.

Can you explain the two areas of “protecting high value assets” and “ensuring operational resilience and stability” and how best manufacturers such as Weibel should respond?

As mentioned, any state has an obligation to protect both its citizens and its governmental institutions. Especially the protection of heads of states are of the utmost importance and these institutionalized individuals are often – by an adversary – considered high value targets and so they require a high level asset protection. To put it blunt, the adversary needs to succeed only once, while we need to succeed every time. That calls for extremely low tolerance which increases the complexity and cost of the needed system (of systems).

As a contrary to this low-tolerance-high-cost demand, commercial actors like industrial ports or airports take a different approach. To them, the counter drone system is an investment in ensuring operational stability and resilience. This motivation leads to a mandatory decision on the trade-off between system costs and acceptable risks. An airport might feel forced to accept some minor risk of perimeter intrusion, as long as the air traffic safety isn’t compromised.

Can you explain the long-range surveillance radar, XENTA and why / how it was developed?

For 45 years Weibel Scientific has developed and manufactured some of the world’s best Doppler Radars. Where a traditional pulse radar needs (at least) two measurements in order to identify an object’s movements, a Doppler Radar uses continuous wave technology thereby providing instantaneous information of an object’s velocity and direction. Our portfolio of Doppler Radars are designed to detect and track all kinds of aerial objects from small projectiles via aircraft to the warheads of an intercontinental ballistic missile thousand miles away. Actually, our largest Doppler Radar is able to discriminate such a warhead from the surrounding decoys and chaffs allowing the ballistic missile defence to engage the right object in a time critical situation.

Approximately five years ago Weibel took it upon ourselves to utilize our know how in Doppler Radar technology to create a drone surveillance radar. To a radar it is a highly complex task to detect and classify a drone. How do you discriminate it from the surrounding birds? How do detect it if it hides in front of an air-condition fan or spinning car wheels? We use supervised machine learning to ensure and continuously improve XENTA’s classification ability, and the radar classifies objects in six categories: Class I drones, Class II drones, missiles/artillery, helicopters, aircraft and birds/unidentified. Off course, when you want to detect very small objects, you also detect a lot more non-interesting objects like trees, cars, wind turbines and so on. To avoid too much of this so-called clutter, we’ve trained XENTA to discriminate between objects in four parameters; direction, elevation, range and velocity. This way, XENTA picks up even the smallest drones without cluttering the radar picture to the operator.

There are quite a lot of very capable short range drone detection radar manufacturers out there, and most of them are very good at detecting drones at 1-2 miles. However, there are only a couple of manufacturers on a global scale that are able to detect drones significantly beyond that range. In what we refer to as the long-range drone detection spectrum, we’ve learned that XENTA is first among equals. Besides detecting and tracking e.g. a Phantom IV sized drone at six miles and classifying it beyond four miles, the radar has extremely high performance in accuracy. Last year, XENTA participated in the Interpol counter drone exercise in Gardermoen International Airport (Oslo, Norway) as well as the NATO Technical Interchange Exercise in The Netherlands. At both events, XENTA succeeded in detecting, tracking and classifying the required aerial targets, and as the only radar it did so without any false alarms – neither false positives nor false negatives. And that is equally important to good detection range.

Can you describe how XENTA counters the growing challenges of drones on commercial safety, homeland security and military capabilities.

XENTA is a long-range drone surveillance radar that uses an open-source interface (e.g. ASTERIX protocol) to ease integration into any air traffic management system, command and control system or similar. XENTA picks up the disturbance in the air from propellers, wings and aerial signature thereby detecting all aerial targets including hostile drones, remotely operated drones and autonomous drones.

In your presentation at CIPRNA 2022 you advocated end-users should work with technical advisers (such as Weibel Scientific) and not to jump to conclusions or make rash decisions. Can you expand on this point?

Putting together a counter drone system a highly complex task. Initially you have to carry out an analysis of the threat. Are your only concern the clumsy but compliant hobby pilots, or do you also need to be able to detect hostile and/or autonomous drones? Afterwards you should analyse the facility you have to protect. Is it a clutter rich environment? Do you have a lot of tall buildings creating masks? Are you only interested in a perimeter protection, or do you also need to be able to track objects that succeed in penetrating your perimeter protection?

After your threat analysis and analysis of your own facility and situation (including regulatory mandates and required time to respond), you can start to look for the sensors you need and the effectors, you are allowed to have. Radars are instruments of physics and so the same laws of nature apply to all radars. Weibel have chosen the X-band (8.5-10.5 GHz) because we believe these wavelengths offer the best trade-off between accuracy and resolution vs. range and weather resilience. If you instead chose the C-band (5-6 GHz), you would – generally speaking – have higher range and better weather resilience, but on the other hand lower resolution and lower “small-object-detection-capability”. Likewise, if you went for a K-band radar (18-27 GHz), you would – again generally speaking – have shorter range and higher weather vulnerability but increased resolution and a better “small-object-detection-capability.

This is just one example that a radar is not just a radar, and you shouldn’t demand from yourself to be able to navigate these highly complex systems. Therefore, the best advice I can give you even without knowing your situation is to ally with a technical expert that can help you translate your operational needs (and financial ability) into technical specifications. When you’ve identified the potential components in your system, you should insist on having them tested in the exact same conditions they will be operating in. The same harsh weather, and the worst scenarios from your threat analysis.

How will Weibel continue to lead the way in tackling drone threats in the future?

At Weibel, we are not interested in feeding you a squared solution to a problem that might be circular. Weibel are deeply concerned with the threat from drones as they are more and more integrated in our modern societies. The most innocent but clumsy behaviour can easily pose great danger to aircraft safety or supply security, and careless or criminal citizens have very easy access to inflict much greater havoc than before. Most people are very enthusiastic with the potential benefits of drones in our daily lives, but not that many have an eye out for the unintentional, negative consequences.

We are using quite a lot of our energy on bringing people together and connecting stakeholders in order to facilitate the best knowledge sharing. It’s imperative that our communities do the right thing from the start. When I look at my own capital, Copenhagen, it’s evident that the airport should acquire their own system, whereas the government is obliged to establish a counter drone system protecting the parliament and the royal family. However, all of these sensors and systems should from the beginning be made ready for integration with each other in a bigger and broader unmanned traffic management system that will enclose the entire capital region. Otherwise we will keep on chasing our own tails for many years to come.