Israeli security officials publicly accused Russia of disrupting and spoofing GPS signal reception in Israeli airspace throughout the month of June. The electronic warfare at which Russia is known to be adept was reportedly traced to the Khmeimim Air Base in Syria, where Russia maintains and actively flies a large number of warplanes on behalf of the Syrian government. The base is approximately about 350 kilometers (217 miles) north of Ben Gurion, so if the accusation is true, fairly powerful equipment is behind the attack.

Both Israeli and other-nationality airline pilots have reported interruptions in GPS reception during take-off and landing at Tel Aviv’s Ben Gurion International Airport. The Israeli Airline Pilots Association labeled the interruptions a spoofing attack, causing airplane receivers to report false positions.

The International Federation of Air Line Pilots’ Associations issued a Notice to Airmen: “GPS signal loss affects RNAV arrivals and departures and may create numerous alerts for systems that rely on internal position accuracy. Flight Crews should be aware of the potential risk, avoid distractions, and plan for alternative procedures as necessary.”

Pilots have since for the most part relied on Instrument Landing System, a precision runway approach aid based on two radio beams which together with both vertical and horizontal guidance during an approach to land at Ben Gurion International Airport.

The Israeli Airports Authority stated that the GPS attacks affected only airborne crews and not terrestrial navigation systems, and that they occur only during daytime.

The Russian ambassador to Israel has denied the accusations.

In April, a U.S. research institute, the Center for Advanced Defense Studies, documented more than 10,000 separate incidents of GPS disruption on Russian soil, in northern Scandinavia and in the Middle East between February 2016 and November 2018. It said Russia was “pioneering” the technique to “protect and promote its strategic interests.” GPS World summarized the report here, stating that “The Russian Federation is growing and actively nurturing a comparative advantage in the targeted use and development of GNSS spoofing capabilities to achieve tactical and strategic objectives at home and abroad.”

Tie-in with Iran Tensions. Meanwhile the Helsinki Times reported that researchers at the Finnish Geodetic Institute noticed unusual power variations in the GPS signal on June 20 and 21: “an increase of up to 10dBHz in the carrier-to-noise ratio readings comparing with the usual daily values.” Normally the variations are between -0.5 and 0.5 dBHz.

The same findings were communicated to the research community by Peter Steigenberger, senior scientist at the German Aerospace Center, DLR:

“Based on carrier-to-noise density ratio observations (C/N0) of IGS receivers, we observed global flex power operations on June 20 and 21, 2019. Flex power started subsequently for all healthy Block IIR-M and IIF satellites on June 20 between 15:18 and 17:49 UTC. C/N0 of the P(Y)-code tracking increased by roughly 10 dB for all healthy Block IIR-M and IIF satellites whereas C/N0 of the C/A-code decreased by about 2-3 dB for the healthy IIR-M satellites only. The changes in power levels are similar to flex power mode III discussed in “Steigenberger P, Thölert S, Montenbruck O. (2019) Flex power on GPS Block IIR-M and IIF, GPS Solutions, doi:10.1007/s10291-018-0797-8″. All satellites returned to normal power levels on June 21 between 6:00 and 10:00 UTC.”

On June 20, a US military drone was downed down by Iranian missiles. On June 21 President Trump tweeted that he had called off a dawn attack on Iran that day.

Whether the spoofing affecting Israeli airspace has any connection to building tensions 1,500 kilometers to the east is unknown.