SUMMERLAND KEY, Fla. — Orbcomm is best known for tracking cargo containers for commercial businesses, but the company has decided to include ship identification receivers on its next batch of satellites in the belief that the U.S. Coast Guard will want to buy the data for homeland security purposes.

The new receivers for Orbcomm’s Automatic Identification System are designed to eavesdrop on the location and identification beacons currently broadcast by vessels on the open seas mostly to avoid collisions. These electronic beacons are meant for short-range, surface communications, but the signals also radiate into low Earth orbit, where Orbcomm of Dulles, Va., operates its constellation of asset-tracking satellites.

Orbcomm hopes to sell the ship data to the Coast Guard, which would incorporate the latitude and longitude, and identification information onto computer consoles monitored by Coast Guard personnel. Shipping interests would not have to install any new hardware nor subscribe to any service, said John Stolte, Orbcomm’s executive vice president for technology and operations.

Coast Guard officials have left no doubt about their interest in the Orbcomm concept, but one Coast Guard official said the Automatic Identification System receivers must be tested in the real world before the Coast Guard, which is now part of the Department of Homeland Security, would commit to buying the data from Orbcomm.

“There’s no silver bullet, but identifying all the good guys, or the majority of the good guys, helps you see what is left over — persons of interest, as the FBI would say,” said Dana Goward, a retired Coast Guard captain who now heads the service’s maritime domain awareness policy office. The Coast Guard then could dispatch crews to investigate unidentified, suspicious ships, he said.

Coast Guard officials are worried that terrorists might hide among commercial shipping traffic and fire missiles at the United States from a ship — a scenario U.S. intelligence officials have dubbed “Scuds in a bucket.” Coast Guard officials have complained loudly about what they see as a shortage of surveillance information about the ships that pass by the United States or enter its ports. These ships typically go unidentified until they come within range of land-based receiving towers, Goward said.

Orbcomm officials are taking a well-calculated gamble that the Coast Guard will decide to buy the new data as a big step toward solving that problem. In 2004, the Coast Guard agreed to pay Orbcomm $8 million to develop the new identification receiver and test it aboard an Orbcomm satellite that tentatively was scheduled for launch in 2005. That satellite is now scheduled for launch before the end of 2006 or in early 2007, meaning the receiver has not been tested in the real world.

Even so, Orbcomm officials were confident enough in the results of ground tests to include the new identification receivers on six new satellites scheduled for launch on a Cosmos rocket before the end of 2007, Stolte said. Orbcomm has filed documents with the U.S. Securities and Exchange Commission (SEC) outlining its plans for a public sale of stock to fund the six replenishment satellites, according to SEC documents.

Orbcomm recently ordered the satellites from Orbital Sciences Corp., which will supply the AIS receivers and other payloads, and OHB-System AG of Bremen, Germany, which will build the satellite frames.

“We’ve tested [the AIS receiver] on the ground. We’re pretty confident we’ll be able to receive the signals,” Stolte said.

The bigger challenge will be sorting through thousands of messages transmitted by ships as they pass through the 3,000-kilometer-wide listening footprint of a single Orbcomm satellite. Mathematical equations and software have been devised to do the job, but testing the system on the ground has proven tricky.

“It’s difficult to simulate that kind of [shipping] congestion in the lab,” Stolte said. “There are some people who say we can do it, and others who say that we can’t. ” Orbcomm also is preparing to order at least 18 completely redesigned “Generation 2” satellites that would be launched after the next batch of six satellites, which aside from the AIS receivers are similar to those currently on orbit. Stolte says he does not yet know whether AIS receivers would be included on the Generation 2 satellites.

“I can’t say yes or no,” Stolte said. “It will be dependent on how well the ones we launch will work.”

If the new ship identification system succeeds, it would mark a fundamental change in the way nations and shipping interests approach maritime security, Goward said.

“I like to tell people that for thousands of years, the key to security for people engaged in maritime activities … has been in anonymity and secrecy,” Goward said.

Commercial ships and military fleets used the vastness of the seas to hide from pirates or rival navies.

“In today’s world, I think the secret to security is transparency. Having everyone know where everyone is, so we can identify anomalies and focus our scarce resources on those anomalies,” Goward said. “That really is a big change from just 50 years ago when secrecy was the key to your security on the water. “