New Possible Chinese Radar Installation on South China Sea Artificial Island Could Put U.S., Allied Stealth Aircraft at Risk

This post has been updated to include additional comments from the Department of Defense.

A possible new Chinese radar installation in the South China Sea could put American and allied stealth aircraft at risk as part of a wider detection network similar to U.S. efforts to find Russian bombers in the Cold War.

Late January satellite imagery from the Center for Strategic and International Studies and DigitalGlobe show the installation of what’s likely a high frequency radar installation the Chinese disputed holding of Cuarteron Reef near the Philippines.

The imagery from DigitalGlobe shows a field on the island with 65 foot-tall poles in a field on reclaimed land on the reef – China’s southern most holding in the region – that are similar to other maritime HF radars, Greg Poling, head of the center’s Asian Maritime Transparency Initiative told USNI News on Monday.

“Why would you have 20-meter poles spread across this features if it’s not high frequency radar? ” Poling said.

“Maybe a giant tarp?”

It’s unclear from the imagery if the site on Cuarteron is operational but the Department of Defense issued a statement to USNI News late Monday that lines up with some of CSIS’ conclusions.

“‎Commercial imagery indicates that China is constructing a new radar system on Cuarteron Reef a disputed feature in the South China Sea. This is part of a growing body of evidence that China continues to take unilateral actions which are increasing tensions in the region and are counterproductive to the peaceful resolution of disputes,” DoD spokesman Cmdr. Bill Urban told USNI News late on Monday. ‎

“We discourage all claimants from unilateral actions. We encourage them to clarify their territorial and maritime claims in accordance with international law and request they commit to resolving their disputes through the use of peaceful dispute settlement mechanisms, such as arbitration.”

The Washington Post first reported the installation early Monday afternoon

Bryan Clark, a maritime analyst at the Center for Strategic and Budgetary Assessments (CSBA), said that while a high frequency radar on the island could have some law enforcement value – like similar radars the U.S. uses to detect drug runners in the Gulf of Mexico and the Caribbean — it’s likely an HF radar on Cuarteron has a secondary military use to detect stealth aircraft.

Similar U.S. and Russian radars can detect surface targets at ranges well over the horizon – 80 to 200 miles. However Chinese and Russian versions could also notice the presence of low observable aircraft, Clark said.

“If I’m China, this is what I want to install so I can monitor maritime and aviation contacts,” he said.

“It’s got a nice dual use. It can find other aircraft that would be hard to find with traditional early warning radar frequencies.”

China has already installed similar radars on its coastline that are used to detect the presence of stealth aircraft.

A possible HF array on Cuarteron could feed what its detects back to mainland China through data links to provide information to radars capable of better targeting stealth aircraft less real estate to scan and then route that data to anti-air warfare missile systems.

The setup “gives you some indications and warning that there are stealth aircraft in the area,” Clark said.

In particular, U.S. stealth aircraft – like the Northrop Grumman B-2 Spirit bomber and Lockheed Martin’s F-22 Raptor and F-35 Lighting II Joint Strike Fighter – are optimized against the high end of the radar spectrum.

Higher frequency radars – on their own — can tell when a low observable or stealth aircraft is in its range but do not have the fidelity to lock weapons. However — as reported by USNI News in 2014 — Russia and China both are perfecting lower band radar that could successfully target low observable aircraft working in conjunction with an HF early warning system. The radars could also provide information to Chinese fighters a general idea where to intercept an adversary.

In addition to the U.S., Australia and Japan are in the process of acquiring F-35s.

The U.S. used a similar idea when it create the Distant Early Warning line to detect Russian bombers starting in the late 1950s.

“It’s the same idea as the DEW Line,” Clark said of an HF array on Cuarteron.

“You could look at this as extending the range of their early warning radars.”

Chris Carlson, a retired U.S. Navy captain and analyst told USNI News that the installation on Cuarteron was much smaller than other similar mainland arrays and its unclear how well the secondary function of the radars would work at the size seen in the images released on Monday.

Additionally, given the location near the Philippines, the alleged HF installation on Cuarteron could also monitor U.S. aircraft movements in the country at long range — all in a package with which China can claim for civilian law enforcement uses, Clark said.

“They can say this is for fishery enforcement and maritime domain awareness and that’s what China will probably claim,” he said.

Beijing has repeatedly said the new installations on the reef, also home to a lighthouse completed in October, are to provide “better public services and goods for the international community,” according to a Monday press briefing with Ministry of Foreign Affairs spokeswoman Hua Chunying.

Last week satellite imagery of Woody Island in the Paracel chain near Vietnam revealed more than 30 mobile anti-air warfare missiles had been placed on the island – raising questions on China’s peaceful intent in the region.

Beijing implicitly defended the move of the HQ-9 system to Woody Island – confirmed last week by Foreign Minister Wang Yi.

“The Chinese side is entitled to safeguard its territorial sovereignty and maritime rights and interests,” Hua said later in her Monday briefing.

“China’s deployment of limited defense facilities on its own territory is its exercise of self-defense right to which a sovereign state is entitled under international law. It has nothing to do with militarization. It is something that comes naturally, and is completely justified and lawful. The U.S. should view that correctly instead of making an issue of that with deliberate sensationalization [sic].”