By Olha Hembik | 2025-09-10

WARSAW -- A massive construction project is underway in a forest in Russia's Kaliningrad region. Trucks deliver materials, and loaders rumble through the site.

In 2023, workers cleared the forest, built roads and erected a fence. Behind it, Russia is constructing a large signals intelligence facility, according to OSINT analysts with Tochnyi, an online platform.

Near Chernyakhovsk, satellite images show a vast circular antenna complex just 25 kilometers (about 16 miles) from Poland's eastern border. The pattern of concentric rings, access routes and a checkpoint stand out. The array spans up to 1,600 meters (some 5,300 feet) in diameter.

The system, known as a circularly disposed antenna array (CDAA), is used for military signals intelligence and communications.

"This is an antenna system used for military signals intelligence and communications ... also known as 'the Kremlin's ear,'" Alexander Antonyuk, a political consultant and serviceman in the Ukrainian Armed Forces, told Kontur. "In terms of scale, it is one of the largest such facilities in Europe."

The facility is significantly larger than known CDAAs, even those recently built in Cuba, allegedly in collaboration with China, according to Tochnyi.

How does it work

A CDAA consists of vertical monopole antennas arranged in concentric rings to detect and locate radio signals.

Its primary purpose is interception. These antennas can capture transmissions across long distances, including military and tactical communications, civilian traffic and even navigation systems, said Antonyuk.

Analysts say CDAAs operate across a range of a few MHz up to 28 MHz and can detect signals as far as 7,400 kilometers (about 4,600 miles).

Antonyuk noted the system "does not jam or disrupt networks, but it transmits coordinates and data to electronic warfare units," which then interfere with communications.

"It is the eyes of those who control this system," he said.

The site enables passive intelligence collection and could expand Russia's electronic warfare reach. Tochnyi analysts call it "a core component of Russia's modern hybrid warfare strategy."

USSR's tactics now

Amid the war in Ukraine, Moscow is turning to advanced listening systems alongside its missile arsenal, Rzeczpospolita reported in August.

Tochnyi analysts said placing the CDAA in Kaliningrad is logical, allowing Russia to monitor NATO's electronic communications across Eastern Europe and the Baltic region.

They added that very low and low frequency capabilities could improve communications with submarine crews in the Baltic Sea and North Atlantic. Similar systems were widely used during the Cold War for direction finding, surveillance, and submarine communications.

"Deploying tactical systems for intercepting radio communications closer to the enemy has been a practice since the time of the confrontation between the Soviet Union and the West," Mykhaylo Zhyrokhov, a military expert, historian and researcher of local conflicts, told Kontur.

He pointed out that the USSR built similar facilities in Cuba and Vietnam, but they were closed in the 2000s due to a lack of funds for maintenance.

"There was an unspoken understanding that the Russians would not use the Kaliningrad Region to build such facilities. But now they don't consider themselves bound to fulfill any agreements, even minimal ones, with the Europeans," added Zhyrokhov.

A new war

Zhyrokhov said Russia is preparing for war with NATO, noting that the General Staff has such a plan in place. He argued that once the war in Ukraine ends, the defense industry, geared to conflict for the past three years, will be unable to pivot quickly to peacetime production.

"A new armed conflict will be necessary to prevent the economy from collapsing. The war will feed this dragon," said Zhyrokhov.

Antonyuk described Kaliningrad as one of the most militarized zones in Europe, with missiles, radars and electronic warfare units already deployed.

"The new facility bolsters this package, making the region a hub for electronic espionage," he said.

Russia's elite Rubicon unit, an electronic warfare force shaped by the war in Ukraine, launches up to 30 drones daily to disrupt defenses and operations. Analysts warn that Kaliningrad's new signals intelligence complex, particularly the CDAA's ability to feed targeting data to electronic warfare units, could amplify those tactics against NATO and strengthen Russia's hybrid warfare.

"In a crisis, this advantage lets Moscow more quickly deploy jamming devices and attack critical communications," said Antonyuk.

Since Russia's full-scale invasion of Ukraine, NATO's eastern members have ramped up defense spending and modernization.

In Poland and Lithuania, work is underway to fortify the Suwałki Gap, a 65-kilometer corridor linking the Baltic states to the rest of Europe and bordered by Kaliningrad and Belarus, Moscow's ally.

Poland is focusing on ground forces and border defenses to close its frontier with Belarus and Russia and to contain the Russian military presence in Kaliningrad.

"Logically, it should be harder for Russia to attack the Baltic states now," Denis Kishinevsky, a Lithuanian journalist with the Current Time TV channel, told Kontur.

The goal is to deter Russia by signaling that any provocation would trigger conflict with major powers, according to Kishinevsky. But Zhyrokhov noted that Moscow still holds an advantage through the combat experience its army has gained in Ukraine.

"Military experience and support from China and Iran could make these systems quite effective against Europe," he said.

Antonyuk urged NATO members and Ukraine's partners to strengthen communication security against emerging Russian threats. He said troops already avoid open transmissions in combat zones, contested areas and frontline cities.

Antonyuk emphasized the need for stronger encryption, reduced use of unprotected channels, frequency hopping and frequent updates to cryptographic keys for data protection.

"All this is no longer just a formality. It is a question of real resistance to Russian espionage," he said.