U.S. Loses Hold on Submarine-Exposing Radar Technique
By WILLIAM J. BROAD
Published: May 11, 1999
Secrets that China stole in 1997 about a space radar that can expose submerged submarines could aid it in finding subs from commercial satellites or airplanes, and might also help it hide its own undersea weapons, intelligence experts say.
For two decades, seeking to protect its submarine fleet from such surveillance, the Pentagon has tried to monopolize the radar. When it made its debut in 1978 with surprising powers of discernment, military officials blocked release of satellite photos that showed deep, normally invisible wakes of speeding craft. Last year, the military had the Government set strict limits on the visual powers of proposed commercial radar satellites. And this year, the Pentagon is fighting a Canadian plan to loft a satellite that would break the new American rules.
Now it turns out, according Federal officials, that an American scientist gave radar secrets to China in 1997, forcibly easing the Pentagon's grip. The implications of this disclosure are unclear, because the size of the breach is unknown publicly and because the secret method is reportedly difficult to put into practice, even after years of study. But at worst, experts say, American subs are now in danger of losing some of their cover. Among the vulnerable are missile subs, the most important part of the nation's nuclear arsenal because of their stealth.
Publicly, the unanswered questions include how deep submarines must go to elude radar prying, how sea currents and temperatures can help restore invisibility and how technical advances with submarines, satellites and computers will most likely affect such probing in the future. Today the radar technique is believed to be able to uncloak submarines hundreds of feet beneath the waves, but not thousands. Experts say that recent trends have already hurt the Pentagon's game, and that China's espionage, at least in theory, has made things worse.
A menacing trend is the advent of commercial radar satellites, which sell their images to anyone with a credit card. Canada has one in orbit and wants another, more powerful. An American company is building one, though the strict new Federal rules forced it to limit its original goals.
As for China, it could use the stolen technology not only to hunt foreign subs but also to better cloak its own submarines, finding ways to reduce the deep wakes that produce subtle clues of stealthy movement.
Angelo M. Codevilla, a professor of international relations at Boston University who has worked on the staff of the Senate Intelligence Committee, said the Chinese would most easily and plausibly use the secrets to change the depth and speed of their submarines. Secret knowledge of ''what we can and cannot do,'' he said, could help the Chinese dodge submarine spying.
Since the start of the space age, most satellites have observed the Earth with cameras similar in principle to any tourist's. In 1978, however, the National Aeronautics and Space Administration launched a new kind of satellite that made images by bouncing radio waves off the planet. Known as Seasat, this radar craft saw land and sea in striking new ways, its images revealing narrow lines in the ocean -- tracings left by the passage of ships and subs. It somehow managed to distinguish signs of deep turbulence from the regular froth and heave of the sea. Seasat's feats came to an abrupt end in 1978 when the spacecraft failed unexpectedly after 100 days, with the Pentagon deeply ambivalent about its discoveries. ''There was concern about what we had done,'' recalled Gene Giberson, the project manager for Seasat at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
Even though the Russians flew nuclear-powered radar satellites to spy on the oceans, the Pentagon -- the Navy in particular -- was loath to look closely at the phenomenon, experts say.
''The Navy resisted,'' said Dave McCurdy, a former chairman of the House Intelligence Committee. ''They didn't want questions raised. There is a certain orthodoxy they didn't want challenged.''
Eventually, in the early 1980's, Congress forced the issue, setting up a research program independent of the Navy that had the issue closely investigated. In 1988, inspired by Seasat, the nation's spy agencies launched their first radar satellite. Mr. McCurdy, now president of the Electronic Industries Association, in Arlington, Va., said the research program found deep-sub imaging ''an incredibly difficult challenge'' that, among other things, required ''a lot of computing power.'' However, progress was sufficient that Britain and the United States kept up the investigations in the 1990's in a joint program. Richard E. Twogood, the program's technical leader, based at Lawrence Livermore National Laboratory, a weapons lab in California, told Congress in 1994 of the discovery of phenomena that ''appear to be very important to the sensing of surface effects produced by undersea disturbances.''
Dr. Twogood also complained that the Defense Department was withholding funds for the research. It was he who told Federal investigators that the radar information given China by Peter Lee, an American scientist, was classified.
A high-ranking Navy submariner said the force was ''not worried about'' the Chinese espionage because the detection technology is ''still of such limited practical use.'' Today, the Pentagon is facing not only Chinese spying but also the global debut of commercial radar satellites, raising knotty issues.
RDL Space Corporation, in Culver City, Calif., wanted a Federal license for a satellite with one-meter resolution, or about three feet. But Washington, at the Pentagon's request, said the company could sell imagery with resolution no greater than 5 meters, or about 16 feet. Last June RDL won a Federal license for that sensitivity. It plans to launch its satellite in 2002. Canada, however, is planning to overstep that boundary with a radar satellite that has a resolution of 3 meters, or about 10 feet. Federal officials, at the Pentagon's request, are now trying to talk Canada into a less sensitive aim.
See also: http://gentleseas.blogspot.com/2012/08/satellite-detection-of-submarines.html