Counter Drone Knowledge Center – ACI World
Technology on both the UAS and C-UAS fronts is changing rapidly. With this evolution, many DTI and C-UAS technologies for airport type environments are still under development but solutions are becoming available. These offer a variety of options for detection, identification and/or mitigation. These comprehensive multi-layered options often combine radar, RF, audio, acoustics, cameras, and artificial intelligence (AI) for detection that could be combined with different mitigation options such as electronic interference or kinetic interdiction. For detection, technology providers have focused on the following technologies considered applicable around airports:
Radar technology plays an important role as the primary means of detecting UAS-based threats. The radar can detect UAS vehicles of any size thanks to its specific radar signature. The radar can search, detect and track multiple objects simultaneously. However, it needs to scan large areas quickly with high sensitivity, and be able to eliminate false hits through different algorithms. Challenges in using radar include lack of automation, reliance on trained operators, high system costs, and variable detection accuracy. A key element in identifying unauthorized drones is the need to find the pilot and the radar is unable to geolocate the UAS pilot.
Radio Frequency (RF)
A more common UAS identification tool is the use of radio frequency or RF. The use of RF scanners provides a cost-effective solution to detect, track and identify UAS over an average detection range of 1-3 km. This detection uses algorithms to scan known frequencies to find and geotag RF transmitting devices with an approximate location of a UAS vehicle and its operator. This is effective if the UAS is transmitting a signal. However, RF detection sensors can only detect a few airborne subjects at a time and accuracy can be compromised by obstacles affecting line of sight. Despite this, the use of RF has a high probability of detection with a low false alarm rate.
A less commonly used detection method, optical sensors can use infrared or thermal imaging as well as a standard daylight camera to detect unauthorized UAS. Electro-optical sensors use a visual signature to detect UAS, while infrared sensors use a heat signature. Optical sensors provide images on the UAS vehicle and its potential payload and can record images as forensic evidence. The challenge with optical systems is that by themselves they can be difficult to detect as they can be challenged by redirection to false targets and are limited by weather conditions. For increased efficiency, the use of optical/infrared could be coupled with radio frequency or radar solutions for UAS detection.
Another tool that could be paired with other detection systems is the use of acoustics that detect sounds produced by UAS engines. These would need powerful algorithms to determine the type of UAS and be able to differentiate between authorized and unauthorized UAS. With this, performance might be affected by wind and other background noise. The cost of this technology is low to medium with a medium probability of detection with higher false alarm rates. Another concern is the lack of geolocation of the operator unlike the other detection methods mentioned above.