The consumer drone market has experienced significant growth in the past few years.
Drones are now widely available. Even high-street retailers and supermarkets sell a wide range of models. And while this has made the skies more accessible to the average person and uncovered a host of new commercial applications, drones pose a serious threat to the aviation and security sectors.
Anti-drone technology continues to advance in response. System integrators have access to a wide range of solutions – from simple and affordable drone detection systems to more advanced, military-grade countermeasures.
The most robust solutions combine different sensor technologies to create a layered system. In this article, we focus on one of the most popular drone detection systems: radio frequency (RF) analysers.
What are Radio Frequency Analysers?
Radio frequency analysers are a type of drone detection system. They come in two main categories:
- Direction finders
- RF signal decoders
Direction Finders
Direction finders combine antennae and interior sensors to detect the control signal or data link that travels between a drone and its control unit. This lets you know when an unauthorised UAV enters restricted airspace so you can take appropriate action.
Typically, you'll need a network of at least 3 RF direction finders to locate a single drone.
RF Signal Decoders
RF signal decoders extract information about the drone and its pilot directly from the drone system data, rather than its RF emissions. They also come in two varieties.
The first are proprietary systems that drone vendors design to work exclusively with their own models. For example, DJI Aeroscope RF decoders detect control signals from any untampered DJI drone. The second type of RF decoder isn't restricted to specific makes and models. Instead, they use reverse engineering to break the encryption on the data link that connects the drone to its control unit.
Individual signal decoders offer better coverage than direction finders, meaning you don't have to deploy them as part of an array to accurately detect drone activity.
Pros and Cons of RF Drone Detection
Pros
- Cost-effective
- Scalable
- Easy to deploy
- Versatile
When you hear ‘radio frequency analyser’, you probably think of hyper-advanced and expensive technology. In reality, RF technology is cost-effective, scalable, and easy to deploy.
Even the most basic radio frequency analysers can detect and, in some cases, identify multiple drones simultaneously. And because they’re passive (i.e., they don’t cause physical damage to the target) you don’t need a license to purchase or install them.
RF analysers are also versatile. Alongside static systems for airports and military airbases, some vendors sell portable solutions that enable law enforcement agencies and security teams to monitor drone activity in the field.
Cons
- Can't detect autonomous drones
- Limited operational range
- Susceptible to adverse weather conditions and terrain
No technology is infallible. And radio frequency analysers are no exception.
Direction finders are only effective as part of an array and are incapable of detecting autonomous drones. Similarly, proprietary RF signal decoders are effectively blind to other models, as well as tampered or homemade drones.
There are also technical limitations that affect both varieties. It's often only the most expensive equipment that can locate and track drones in real-time. In addition, radio frequency analysers are less effective in areas with high radio traffic, poor meteorological conditions, or rugged terrain. This can significantly reduce their operational range compared to other, more advanced drone detection systems, like radar.
Vendors of RF Drone Detection
Rhode & Schwarz
Munich-based Rhode & Schwarz combine over 85 years of industry experience with market-leading technological expertise to develop, manufacture and sell a comprehensive range of radio frequency analysers.
Its ARDRONIS product line functions as a critical early warning system for civil and military aviation. Each model can automatically classify the type of drone signal, determine its trajectory, and locate the pilot. ARDRONIS can even disrupt the radio control link between a drone and its controller, which prevents the drone from reaching its target.
A detailed product list is available on the Rhode & Schwarz website.
RF Drone Detection: The Right Choice?
Radio frequency analysers are less effective than purpose-built drone radars at tracking and monitoring drone activity over a wide area, due to their limited range and sensitivity to atmospheric conditions.
Much like optical and acoustic sensors, RF analysers are best deployed as part of a wider network of counter-measures that incorporates purpose-built drone detection radar to provide unparalleled coverage.
