China has established a novel system for using land-based ballistic missiles to deter America's powerful nuclear-powered aircraft carriers from coming anywhere near its coast, says a team of Indian analysts.

A constellation of satellites and at least one over-the-horizon radar give its Anti-Ship Ballistic Missile (ASBM) system the capability to work out the position of U.S. aircraft carriers at sea, according to assessments published by researchers at the National Institute of Advanced Studies in Bangalore.

Land-based ballistic missiles, carrying manoeuvrable warheads with conventional munitions, could then, if needed, target the aircraft carriers at a distance of about 2,000 km.

The ASBM had “shaken the traditional view of the U.S. Navy’s unassailable superiority in the Pacific,” according to a report prepared by a group of experts with the Institute's International Strategic and Security Studies Programme.

The system “will serve as a credible deterrent against American intervention in China's maritime disputes, of which it has several with its Asian neighbours,” it noted.

“No one thought it was possible to target moving aircraft carriers with long-range ballistic missiles,” remarked S. Chandrashekar who participated in the assessment. The Chinese had come up with “a very innovative system” based on well-understood components.

China's constellation of Yaogan military satellites includes those for electronic intelligence (ELINT) gathering that detect radio signals and other electronic emissions from an aircraft carrier and its associated warships. China currently has three clusters of ELINT satellites that provide global surveillance.

In each cluster, there are three satellites that maintain a triangular formation in orbit and can locate ships producing radio signals with an accuracy of 25 km to 100 km, according to him.

The Yaogan constellation also includes radar satellites as well as satellites with optical sensors that can establish the position of the aircraft carriers with much greater accuracy.

In the course of a single day, the current Yaogan constellation can provide about 16 targeting opportunities for ballistic missile launches when the uncertainity in an aircraft carrier's position will be less than 10 km.

“These preliminary results suggest that China has in place a space-based surveillance system that can identify, locate and track an aircraft carrier in the Pacific Ocean,” according to a recent report prepared by the analysts.

Although the land-based ballistic missiles can target aircraft carriers using just the Yaogon constellation, the number of targeting opportunities become fewer if cloud cover obscures the view of satellites with optical sensors, observed Prof. Chandrashekar.

By incorporating an over-the-horizon radar that can continually track aircraft carriers up to a distance of about 3,000 km, the Chinese gain the flexibility to launch the ballistic missiles whenever they choose, he pointed out.

He and his colleagues also found that China could modify its proven DF-21 ballistic missile to carry a manoeuverable warhead. With an onboard radar, the warhead could, as it is descended through the atmosphere, precisely locate the moving aircraft carrier and then adjust its trajectory to strike the ship with conventional munitions.

Their analysis of openly accessible images of the DF-21D indicated that this missile variant met the dimensional requirements for such a mission. It could hit ships that were about 2,000 km from the Chinese mainland.

The F-18 Super Hornet, the U.S. Navy's main carrier-borne attack aircraft, has a mission radius of about 750 km. China would therefore want to prevent America's formidable Carrier Strike Groups from venturing within 1,000 km of its coast, their report observed.

The Chinese military is known to have successfully tested the ASBM against a land-based simulation of an aircraft carrier, according to him.

“The open literature does not provide any information about whether the system has also been tested with a ship at sea,” he told this correspondent.