BOSTON — The U.S. Air Force has scaled back plans for a ground-based satellite-interference location and characterization system to keep its costs under control, the service said in a written response to questions.

The restructuring of the Rapid Attack Identification Detection and Reporting System (RAIDRS) program also will result in a one-year initial deployment delay, to September 2008, the Air Force said in a statement provided by Candrea Thomas, a spokeswoman for the service. The Air Force said the restructuring was undertaken because RAIDRS prime contractor Integral Systems of Lanham, Md., underestimated the scope and complexity of the work.

Integral won the RAIDRS prime contract, potentially worth $123 million, in February 2005, beating out Arrowhead Global Communications of Falls Church, Va., and Innovative Technology Systems of Colorado Springs, Colo. The program was geared toward small businesses as part of an Air Force effort to expand its contracting base.

RAIDRS will consist of a central hub station and fixed-site and mobile antennas deployed around the world to detect, locate and characterize sources of radio frequency interference to U.S. military and commercial satellites. The system, as envisioned, also would determine whether or not the interference is intentional.

The Air Force has not yet determined the sites for the antennas, which are capable of detecting electromagnetic interference in frequency bands including X, Ku and C, according to the Air Force statement.

Under the restructuring, the Air Force will reduce the number of RAIDRS sites from 36, each with a single antenna, to nine with multiple antennas, the service said. Six of those sites would be fixed, while the others would be mobile, the service said. This new approach is intended to save on integration, deployment and maintenance costs, according to the statement.

Integral currently is under firm contract to deliver a central operating hub for the RAIDRS system and one mobile antenna site. The Air Force has not yet exercised options for the eight additional antenna sites, according to the statement.

By scaling the system’s capabilities back to meet threshold, or minimum, requirements, the Air Force expects to keep RAIDRS from exceeding its projected budget, according to the statement. The program has not run into technical difficulty, but was restructured because Integral underestimated the workload, the statement said.

The restructuring is expected to delay the availability of the fully capable system in addition to the initial deployment. The program has a hard requirement for full capability by September 2011, but Air Force officials previously believed they could get there two years earlier. Now, however, the service does not expect to have a fully capable system — which will include a backup hub station — before March 2011, the statement said.

While Integral will now focus on a system with the minimum capabilities required to detect and characterize disruptions to U.S. satellites, the Air Force has established a plan for incremental delivery of more capable equipment, according to the statement.

Capabilities that have been deferred until the system reaches full operational capability include the ability to locate sources of UHF radio frequency interference , according to the Air Force statement.

The Air Force announced Feb. 27 that it would modify Intergral’s RAIDRS contract by $15 million to cover the cost of the restructuring. The Air Force statement said the value of Integral’s contract is now $42.3 million.

Dilene Cruickshank, an Integral spokeswoman, said company officials would have no comment on the RAIDRS program.