China's 'Stealth Ships' Aren’t So Stealthy After All

China's Type-022 missile boats have long been seen as stealthy.

The boats feature sharp angular lines and hidden missile launchers.

In reality, the boats show up in commercially available radar scans of the Chinese coastline.

China's largest class of warships—once thought to be wholly resistant to radar detection—are actually quite visible to radar scans after all.

The Houbei-class fast-attack boats, which bristle with anti-ship missiles, are easily seen in Synthetic Aperture Radar (SAR) that remote sensing companies use, according to naval authority H.I. Sutton, author of the Covert Shores blog. He has uncovered convincing evidence that the Type-022's radar-evading design is a myth. This calls into serious question whether other forms of radar can detect the boats, too, and whether or not their stealthy lines are actually just for show.

In the mid-2000s, China built a fleet of 82 Type-022 fast-attack craft. Known as the Houbei-class, the tiny boats are just 141 feet long and displace 250 tons. A catamaran design, each can sail at a top speed of 36 knots and support a crew of 14. Each is equipped with an AK-630 30-millimeter Gatling gun and eight YJ-83 anti-ship missiles, giving them the firepower of a destroyer. China likely built the large fleet of ships, useful for coastal defense, as a response to the aircraft carrier USS Nimitz's transit of the Taiwan Strait in 1995. At the time, the People's Liberation Army Navy was powerless to stop the carrier from passing through the waterway separating Taiwan from mainland China.

The Type-022 boats have long been seen as stealthy. The boats have a low profile in the water, flat surfaces, and sharp, angular lines. The eight anti-ship missiles are carried above deck, but in sloped box launchers that are part of the hull (rather than in individual missile canisters like Harpoon missiles on the deck of an Arleigh Burke-class destroyer).

Sutton agrees that the Houbei-class boats certainly look stealthy: "Everything is carefully angled and even the window frames have saw-tooth edges," he notes in a piece for USNI News. Even Combat Fleets of the World, the authoritative guide to navies worldwide, describes the Type-022 class as including "numerous signature reduction and stealth features."

Well, maybe not.

Sutton worked with San Francisco, California-based Capella Space to show that space-based Synthetic Aperture Radar can easily detect the boats. Various features of the boats are visible in the radar images he acquired, including the bow and missile box launchers.

Radar covers a large band of frequencies in the electromagnetic spectrum, and the bands, typically named with a Roman letter, often have unique capabilities. Synthetic Aperture Radar, for example, can penetrate clouds, rain, and even tree canopy cover to survey the ground below. This makes it particularly suitable for remote Earth-sensing duties, including tracking forests, ice, and even different types of agricultural crops. Capella satellites use X-band radar in the 9.4 to 9.9 Gigahertz range.

So, is the Type-022's detectability by Synthetic Aperture Radars a problem for the Chinese fleet? It's quite possible. The AN/APG-81 radar mounted on the nose of the F-35 Joint Strike Fighter also operates in the X-band. Ticonderoga and Arleigh Burke-class cruisers and destroyers use the SPY-1 radar system (which operates in the S-band), which is also used to an extent in Synthetic Aperture Radar. Other military surveillance assets, including satellites and aircraft, also use dedicated SAR radar to track everything from tank columns to the periscopes of submarines.

Photo credit: Getty Images

Fortunately, there are real stealth ships.

The Arleigh Burke-class destroyers were the first surface combatants in the U.S. Navy built with radar reduction in mind. Although the Burke-class ships are covered from bow to stern with guns, antennas, missile launchers, and even hand railings, they are thought to incorporate some level of radar efficiency reduction. (That's a good thing for wartime, not so good for peacetime, when navigating around commercial ships that rely on radar for situational awareness.)

The kings of stealth at sea are the U.S. Navy's three Zumwalt-class stealth destroyers. The Zumwalt, Michael Monsoor, and Lyndon B. Johnson appear in some ways similar to the Type-022, but the U.S. military's long experience with stealth means their covertness is unquestionable. Each of the destroyers is 600 feet long, yet reportedly appears the same size on radar as a small fishing boat.