Government to Delay Satellite Tracking of Trucks, Planes, Trains and Ships

WASHINGTON (AP) 3/26/02 - Government plans to use satellites only to track planes, trains, trucks and ships will be delayed because signals can be blocked or jammed, according to a report issued Tuesday.

The report by the Transportation Department and Defense Department said it would take longer than originally planned to reduce land-based tracking systems. It said most of the land-based systems would begin to be phased down in 2010, rather than 2008.

"We are seeking a sensible transition to satellite-based navigation services as our primary means of navigation, while recognizing the need to maintain backup navigation aids where required," Transportation Secretary Norman Y. Mineta said.

The problem is satellite signals, arrayed as the GPS or Global Positioning System, could be blocked by buildings or interference from other transmissions. The signals also could be jammed.

The warning came last September from the Transportation Department's Volpe National Transportation Systems Center.

Mineta said earlier this month that the agency would keep its backup system to track airplanes and would obtain Defense Department technology to try to prevent outsiders from jamming signals from the satellites.