Stealthy Soviet Subs Have US Detection Experts Scurrying

SINCE the mid-1980s the Central Intelligence Agency has been tinkering at sea with technology for finding and tracking Soviet submarines. This novel research effort shows how sensitive antisubmarine warfare (ASW) is. It also hints at how fragmented the US antisubmarine research effort has become, with different parts of the Pentagon as well as the CIA proceeding with their own programs.

With the Soviets launching new generations of stealthier subs, ASW is one area of defense where the United States may have to spend more money and effort in coming years, according to a new congressional report.

``The Soviets have now begun to build submarines that are quiet enough to present for us a major technological challenge with profound national security implications,'' concludes the study, produced for the House Armed Services Committee by a panel of 10 experts in the field.

In fact, the Soviet sub fleet may soon be quiet enough to make passive sonar, the traditional US anti-sub technology, obsolete. According to the report, projected improvement in passive sonar sensitivity will not be enough to detect the newest subs in the Soviet fleet at adequate ranges. ``Better passive sonars are not the answer,'' the report says.

The US Navy must instead expand its ASW vision, congressional staff members say. Nontraditional ASW methods should be explored, such as active sonar (which bounces an electronic beam off objects, instead of simply sensing sounds), magnetic detection, and perhaps even satellites that detect ripples in ocean currents.

Navy officials, for their part, have said that ``tactical oceanography'' is one ASW area that holds promise. This involves studying the weather in the ocean to learn how currents, salinity, and now little-understood phenomena affect how sound travels at sea. Such knowledge could greatly improve the effectiveness of current passive sonar technology.

``There are `storms' in the ocean that can last for years,'' one congressional staff aide points out.

One surprise in the House committee study was a short reference to the CIA's involvement in antisubmarine research.

Study authors declined to elaborate, but one person involved in the report process said that ``reading between the lines, you can see that subs are involved in intelligence collection.''

The CIA should continue its work, said this staff member, though perhaps it could be pruned somewhat for efficiency's sake.

Antisubmarine warfare efforts have long been a contentious issue on the congressional Armed Services committees.

Many influential members have felt that the Navy was focusing too much effort on short-term technology. Specifically, critics have complained that the new Seawolf attack submarine and its assorted sub-tracking electronics are not enough of an improvement to justify the vessel's cost of more than $1 billion a copy.

Even critics now say ASW deserves more money, however. ``We recommend that this work should be considered as one of, if not the, highest priority activities in the Department of Defense,'' concludes the House report.