In the U.S., the Nationwide Differential GPS system is a major example (see NDGPS). See GPS, LORAN, Galileo and Selective Availability.

TYSONS CORNER, VA, Dec. 13, 2016 ” Lockheed Martin (NYSE: LMT) will update the U.S. Air Force ‘s GPS satellite ground control system to support GPS Block III satellite operations as part of ...

GPS OCX is a ground control system designed to monitor, track and update GPS satellites and is divided into three blocks. Delivery of Block 0 occurred in the fall of 2017.