Expert says spoofing may have caused drone to fall in Lithuania

An aviation engineering expert says signal spoofing likely affected the drone that fell in Pasvalys district on Sunday. Saulius Japertas, an associate professor at Kaunas University of Technology, also said Poland and Belarus may have seen the aircraft but could not take serious measures because it was flying close to the border, LRT reported.

Japertas said long-range drones typically use GPS and an inertial navigation system. A third system, which uses visual information, may also have been fitted to the drone that fell in Pasvalys district.

He compared GPS to sight and inertial navigation to hearing. GPS is accurate but vulnerable to electronic warfare, while an inertial system is resistant to such interference but much less accurate, he said.

Japertas said Russian electronic warfare systems may have imitated satellite signals, generating a stronger false signal that the drone then followed. He said the aircraft could have been a Ukrainian Liutyi, Bober or Palianytsia drone, models capable of carrying 50 to 75 kilograms of explosives.

The expert said a visual navigation system may also have failed because of the dense fog on Sunday. He added that when GPS and visual navigation are unavailable, a drone relying only on inertial navigation may continue along a steady path rather than correct its course for crosswinds. That could indicate a loss of control, though it would not prove it.

Doppler radar can help distinguish a drone from a bird, Japertas said. Their speeds and radar reflections may be similar, but the systems can detect differences between a bird’s wingbeats and a drone’s rapidly spinning propellers.

The drone entered Lithuanian airspace on Sunday morning and fell in Pasvalys district. Defence Minister Robertas Kaunas said the incident was a consequence of a Ukrainian attack on St Petersburg. Prime Minister Mindaugas Sinkevičius said after a meeting of the National Security Commission that the drone had entered Lithuania from Poland and was carrying explosives.