Small unmanned aerial vehicles (UAVs) are increasingly becoming a challenge for both civilian and military security. Even simple modifications of these inexpensive and widely available systems can create a serious threat which potentially causes major damage. Using signals from global navigation satellite system (GNSS), UAVs are able to operate over long distances and to find their target zone without remote control of a pilot. In this flight mode, radio direction finder cannot detect any transmitted signal. Typical countermeasures like RF jamming or Wi-Fi hacking become ineffective to stop the threat.

The DLR smart GPS spoofing approach is a promising technology for a cost-effective countermeasure against such autonomously flying Micro UAVs. Several dedicated devices must reliably interact to fulfil this task. The optical identification and position measurement of the UAVs was developed at the DLR Institute of Technical Physics. By optimizing the tracking processes and the laser ranging systems, even small and agile targets can be tracked. The measured position and flight data are forwarded to a GPS spoofing system developed by the DLR Institute of Communications and Navigation. The emitted GPS signal is modified in such a way that the UAV leaves its original flight trajectory and is redirected to a save one. Outside the protected area the UAV can be forced to ground without collateral damages. The feedback loop via the independent optical position measurement ensures that the desired flight trajectory is maintained. The basic functionalities of the smart GPS spoofing countermeasure were successfully demonstrated in realistic field tests. The optical setup and first results will be discussed.