CRFS breakthrough extends counter UAS detection capabilities


CRFS, a global leader in RF spectrum monitoring and geolocation solutions, has released a new version of its spectrum monitoring software, RFeye® Site, that extends the range and accuracy for detecting and geolocating hostile or unauthorized drones.

The patented technology employs three new features that can provide operators in charge of facility security with an early warning of approaching drones and greater precision in geolocating the targets.  These new features include Antenna Sequencing, TDOA Synthetic Vector, and Intelligent Receiver Selection.

The sooner an operator can be alerted to the presence of a drone, the sooner they can decide what action to take,” said Malcolm Sellers, CRFS Product Manager. “These new features in RFeye Site extend the drone detection capabilities and provide a crucial advance warning of an approaching threat.”

The new features include:

Increased detection range with RFeye Node antenna sequencing

The first new feature is the ability to automatically sequence between directional and omni-directional antennas on the same RFeye Node receiver. By using a high gain directional antenna, facing the most likely direction of a potential threat, detection and geolocation range can be dramatically extended. An omni-directional antenna can be utilized on the same receiver to cover other directions and deliver comprehensive coverage. RFeye Site can cycle through these antenna types at rapid speed in a sequence designed to maximize probability of intercept.

Advanced warnings with Synthetic Vectors

TDOA Vector

With small COTS drones, Time Difference of Arrival (TDOA) geolocation is accurate to ~5km from the center of the Node receiver network. At greater distances, achieving highly accurate geolocations can become challenging. The latest release of RFeye Site, includes the ability to create a Synthetic Vector (line of bearing) from TDOA geolocations, which will deliver the bearing and RMS of an acquired target up to 10km from the center of the Node network.

This early warning will help an operator ensure they have other detection sensors, such as radar and EO, pointing in the correct direction as the drone approaches. Once the drone gets closer, RFeye Site will automatically switch to geolocation mode to be able to accurately geolocate the drone in three dimensions and feed this data into any available counter measure.

Improved TDOA accuracy with intelligent RFeye Node selection

Where there is a high-risk high of unauthorized drone activity, such as an airport, customers have chosen to deploy a greater number of RFeye Nodes around the installation for increased coverage.

However, if all the Nodes in the network are asked to contribute to a geolocation, the result can be negatively impacted by poor line of sight and sub-optimal network geometry. Instead of manually selecting the best placed RFeye Nodes for the geolocation, RFeye Site now takes in the incoming data from all the Nodes in the network, and automatically selects the best Nodes to carry out the 2D or 3D TDOA geolocation. This automatic Node selection noticeably improves accuracy, giving the operator increased confidence in the geolocation result.

These new features are available now in RFeye Site V1.50 to all new and existing customers with current support contracts. More information can be found at


About CRFS

CRFS creates deployable systems to detect, identify and geolocate signals in complex RF environments. We provide end-to-end automated solutions for spectrum management and deconfliction, interference hunting and threat detection, using our intelligent receiver technology, software and advanced analytics. Our RFeye systems are widely deployed by military, intelligence, law enforcement, and regulatory agencies.

CRFS designs, builds, programs and deploys systems and solutions from their production facilities in the UK and USA. We also have a network of trusted international partners that provide local support to our global customer base.


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