White Paper
Limitations of Decoding/Decrypting
Relying on Radio Frequency (RF) decoding alone for UAS detection and location is quickly becoming unreliable in the face of ever-advancing RF encryption, spoofing and autonomy.
RF decoding hacks into the RF signal to read communication between the drone and its remote to extract data such as GPS coordinates (if available), altitude, and speed. However, there are many limitations to relying solely on decoding in one’s security apparatus.
Most importantly, in the United States and many other countries, it's illegal to decode these signals. Only the AeroScope® can circumvent these restrictions because it leverages DJI’s End User License Agreement (EULA), that all DJI users agree to when they perform the initial setup and configuration of their drone, thus allowing for this transfer of information.
Many drones, including DJI encrypt their RF signals to avoid being located. These encryption keys can be easily updated and changed to ensure that decoding remains not only expensive but also unreliable. The moment it is known that an RF signal is understandable, the manufacturer or user can simply leverage a new encryption mechanism.
Not all drones come equipped with GPS boards installed. Therefore, if there is no GPS board then there is no coordinate data to extract even if decoding is possible. This non-existant GPS board issue is particularly true for the DIY drone market.
Unencrypted drone data can be susceptible to tampering. The concern lies in the potential manipulation of data transmitted by drones, a tactic known as spoofing. Spoofers can alter drone signals, making them seem to originate from a different location or masquerade as another drone altogether. Equally, spoofers can easily generate a drone signal where there is no drone at all. This presents a substantial hurdle in drone detection efforts, especially when relying on RF decoding techniques.
Today, we see all of the above hurdles being implemented on both sides of the Ukraine/Russian conflict to hide the true location of unmanned aircraft systems (UAS) in the skies above. These techniques will quickly migrate to other parts of the world as users become more sophisticated.
RF Localization Through AoA/TDoA
Alternatively, RF Localization through AoA / TDoA offers a failsafe and legal way to detect and locate drones.
In this methodology, one sensor can be used to determine the direction of the drone and multiple sensors can be leveraged to calculate the exact position of the drone based on triangulation from multiple direction sensing sensors.
Measures difference in time of arrival between several sensors. TDoA depends on the distance between the drone and sensors.
Conclusion
RF Localization through AoA / TDoA is 100% legal in the United States as these methods simply identify the RF communication without reading it. Additionally, because AoA / TDoA methods focus on signal origin rather than signal content, they cannot be bypassed, encrypted or spoofed, unlike decoding. AoA / TDoA are preferable for applications where the reliability and authenticity of drone detection are paramount.
Relying solely on decoding technology is becoming impractical in the face of advancing drone technologies. Today’s reality calls for a more versatile and adaptive approach to drone detection that moves beyond the limitations of decoding. Incorporating a multi-sensor strategy, which includes RF triangulation, radar, and camera sensors, will provide a more robust and effective response to the complex and evolving nature of drone threats.
Kai Baumgart, Director of RF Development
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