"The Federal Radionavigation Plan (FRP) is the official source of radionavigation policy and planning for the Federal Government. The FRP covers common-use, Federally operated radionavigation systems. These systems are sometimes used in combination with each other or with other systems. Systems used exclusively by the military are covered in the Chairman, Joint Chiefs of Staff (CJCS) Master Positioning, Navigation, and Timing Plan (MPNTP). The plan does not include systems that mainly perform surveillance and communication functions. The policies and operating plans contained in this document cover the following radionavigation systems: 1. Global Positioning System (GPS) 2. Tactical Air Navigation (TACAN) 3. Augmentations to GPS 4. Instrument Landing System (ILS) 5. Loran-C 6. Microwave Landing System (MLS) 7. VOR and VOR/DME 8. Aeronautical Nondirectional Radiobeacons (NDB) The Federal Government operates radionavigation systems as one of the necessary elements to enable safe transportation and encourage commerce within the United States. It is a goal of the Government to provide this service in a cost-effective manner. The Department of Transportation (DOT) is responsible under title 49 United States Code (U.S.C.) Section 301 for ensuring safe and efficient transportation. The Department of Defense (DoD) is responsible for maintaining aids to navigation required exclusively for national defense. The DoD is also required by statute 10 U.S.C. 2281(b) (Ref. 1) to provide for the sustainment and operation of GPS for peaceful civil, commercial, and scientific uses on a continuous worldwide basis free of direct user fees."
U.S. Coast Guard: http://www.uscg.mil/