...the system being tested in Middletown, by Naval Undersea Warfare Center researchers and 10 military contractors such as DRS Technologies Inc., is the first to employ software that incorporates data from multiple types of sensors.

The goal, Carmichael said, is to reduce false alarms caused by surf, sea mammals and small boats, easing the demands on port patrols while heightening protection against incidents similar to the 2000 attack on the American destroyer Cole, severely damaged while docked in Yemen...

...The prototype “data fusion” system being developed in Rhode Island, however, is designed to be operated by mobile teams that will accompany Navy expeditionary forces.

But for that mission, the Navy will have to find a lightweight sonar head. The one used in last week’s test — a bulky, blue egg made by the British firm QinetiQ — weighed 600 pounds. (Next month, several companies, including Sonardyne International Ltd. will come to Middletown to demonstrate deployable sonar heads.)