Lockheed Martin Corp (LMT.N) said it is working to resolve a technical error disclosed by the U.S. Air Force on Sunday that affected some global positioning system (GPS) satellites but did not degrade the accuracy of GPS signals received by users around the world. Lockheed said the error involved the ground control system for GPS satellites it runs for the Air Force. Lockheed spokeswoman Christine Courard said the company had put a “workaround” in place to avoid further errors and was working on a full software correction with the Air Force.