The U.S. Coast Guard, the U.S. Army Corps of Engineers (USACE), and the Department of Transportation (DOT) have released a Federal Register Notice announcing a reduction of the Nationwide Differential Global Positioning System (NDGPS). The planned reduction calls for the shutdown and decommissioning of 37 DGPS sites, leaving 46 operational sites available to users in coastal areas. The full notice can be found via this link: https://federalregister.gov/a/2016-15886
Summary: The Nationwide Differential Global Positioning System (NDGPS) service augments GPS by providing increased accuracy and integrity using land-based reference stations to transmit correction messages over radiobeacon frequencies. The service was implemented through agreements between multiple Federal agencies including the United States Coast Guard (USCG), Department of Transportation (DOT), and United States Army Corps of Engineers (USACE), as well as several states and scientific organizations, all cooperating to provide the combined national DGPS utility. However, a number of factors have contributed to declining use of NDGPS. Based on an assessment by the Department of Homeland Security (DHS), DOT, and USACE, the agencies will shut down and decommission 37 DGPS sites, which will leave 46 operational sites available to users in coastal areas. Termination of the NDGPS broadcast at the 37 sites is planned to occur on August 5, 2016.