TAMPA - The research group SRI International in St. Petersburg plans to announce a major research project with the U.S. Navy for sensors that rapidly make three-dimensional underwater maps showing features as small as a soda can.

Details of the contract could be announced in late August, and the work could expand beyond underwater mapping, SRI officials said. It's the third significant research deal for the St.Petersburg office of the highly regarded Silicon Valley-based SRI, which has played roles through the years in developing the first Internet software, the computer mouse and medical ultrasound.

SRI opened a site in St. Petersburg last year to explore issues such as marine science,human aging, education and port security.

"This project continues to expand our marine science complex here and is part of SRI's work toward very important problems," said Larry Langebrake, director of SRI's St. Petersburg facility.

By year's end, SRI plans to break ground on a $35 million waterfront building in St. Petersburg adjacent to the U.S. Coast Guard station.

SRI is technically a nonprofit research corporation. It often takes federal research funds or signs contracts with the military or major corporations to explore a topic, develop a new technology then spin it out into new companies.

SRI has hired about 68 people in St. Petersburg, most with advanced degrees, and opened satellite offices in Tampa, Orlando and the Florida Panhandle.

It has started reaching out to the University of Florida, the Tampa Bay Technology Forum and has helped attempts to recruit the Cambridge, Mass.-based Draper Laboratory, a contract researcher in fields as diverse as biotechnology and missile-guidance technology.

Ultimately, SRI could employ 200 people in Florida, Langebrake said.

Many of its St. Petersburg workers came directly out of the University of South Florida's marine science program at St. Petersburg. So far, that office has been involved with education research, port security and ways to make energy from the motion of ocean waves.

That expansion was aided by $35 million in state and local economic development funds, with land for a new site given by the City of St. Petersburg. The goal was to aid SRI in creating new projects that can make Tampa Bay more of a research hub, ultimately creating and attracting new companies to the area.

In that regard, SRI already has helped attract one company to open offices in the region, New York-based Coda Octopus Group, which develops underwater mapping equipment.

The Navy project will tap into SRI's work in underwater mapping, which uses a combination of sonar and lasers. The system can take rapid scans of a region and assemble the data into a three-dimensional map of the terrain. By taking multiple scans at different times, the system can detect changes and new objects that could indicate such things as cracks in bridge pilings or bombs placed on ship hulls.

The Navy has scuba divers regularly scan the bottom of vessels with their hands and flashlights before entering or leaving a port, Langebrake said. With this system, a scanner could automate much of that work.

As a test, SRI mapped several barges that sank off St. Petersburg while carrying debris from disassembling the old Gandy Bridge, detecting fist-sized rocks on the vessels.