Of all the drone-related incidents to make the headlines in recent years, few are as infamous as the one that brought Gatwick Airport to a standstill in December 2018.
Affecting over 1,000 flights and 140,000 passengers, the incident cost Britain’s second-largest airport £1.4 million. To this day, it remains an object lesson in the threat drones pose to civilian and military aviation and serves as a timely reminder of the importance of effective countermeasures.
Anti-drone technology comes in many shapes and sizes, ranging from detection and monitoring equipment to more active countermeasures. The most robust solutions combine different sensor technologies to create a layered system.
But today, we take a closer look at one of the most common drone detection systems: acoustic sensors.
Why Use An Acoustic Sensor Against Drones?
Acoustic sensors are, essentially, powerful microphones that can be used to detect unauthorised drone activity and protect assets.
Acoustic sensors form part of an array that picks up on the sound drones emit during flight to detect their presence and calculate their direction of travel. Larger, distributed arrays can even triangulate the rough position of individual drones.
What sets acoustic sensors apart from other solutions is their ability to detect both manually controlled and autonomous drones. Working in tandem with radar, cameras, and radio frequency analysers, they can fill an important gap in your drone defences.
Pros and Cons of Acoustic Sensor Against Drones
Pros
- Detects all types of drones
- Highly mobile
Acoustic sensors are simple but effective.
Unlike radio frequency analysers, acoustic sensors can detect any drone within the near-field of the electromagnetic spectrum – including autonomous units that don’t require radio waves to function. They can also differentiate between ground clutter and genuine drone activity, which some drone detection systems can struggle with.
Acoustic sensors are completely passive, which means you don’t need any additional licenses to operate them.
Cons
- Ineffective in noisy environments
- Limited range (max. 300-500m)
- Affected by wind direction and temperature
Though popular in both civil and military aviation, acoustic sensors are ineffective as a primary drone detection system.
With a maximum range of between 300-500m, acoustic sensors offer only limited coverage compared to other systems. Background noise, wind direction, and temperature can also reduce the effective range of an acoustic sensor array.
Drone swarms pose another problem.
Acoustic sensors can identify a swarm, but they may struggle to distinguish between individual drones within it. To identify and track multiple targets simultaneously, you need a more advanced radar systems.
Vendors
Squarehead Technology
Founded in 2004 and based in Norway, Squarehead Technology is one of the market leaders in precision acoustic detection.
Squarehead’s flagship product, the Discovair G2, filters out unwanted background noise to provide superior range and more reliable drone detection than conventional systems. Whether deployed independently or integrated with complementary drone detection and mitigation systems, the Discovair’s patented microphone array provides 24/7 coverage in a range of conditions. And it doesn’t require direct line-of-sight to be effective.
Head over to the Squarehead website for full product specs.
Enhance Your Drone Detection Capabilities
Acoustic sensors are at their most effective when they’re part of a network.
Even the most sophisticated drone detection solutions have blind spots. But by combining them, you can overcome the individual weaknesses of each technology and mitigate drone threats before they become a serious problem.
