North Warning System
Active	1988–present
Country	Canada &United States
Branch	Royal Canadian Air Force United States Air Force
Type	Early-warning radar
Role	Continental Air Defense
Part of	North American Aerospace Defense Command
Garrison/HQ	CFB North Bay Joint Base Elmendorf-Richardson

TheNorth Warning System (NWS,French:Système d'alerte du nord) is a joint United States and Canadianearly-warning radar system for the atmosphericair defense of North America. It provides surveillance of airspace from potential incursions or attacks from across North America's polar region. It replaced theDistant Early Warning Line system in the late 1980s.

The NWS consists of both long rangeAN/FPS-117 and short rangeAN/FPS-124 surveillance radars, operated and maintained byNorth American Aerospace Defense Command (NORAD).^[1]: 16 There are 13 long range sites and 36 short range sites.

In Canada, the station sites are owned or leased by the Government of Canada, which also owns most of the infrastructure. The radars and tactical radios are owned by theUnited States Air Force.^[1]: 16 The Alaska Regional Operations Control Center (ROCC) atElmendorf AFB, Alaska controls the stations in Alaska; the Canada East and Canada West Regional Operations Control Centres (ROCCs) atCFB North Bay, Ontario control the stations in Canada. ROCC information is then passed to the NORAD Combat Operations Centre (COC) at Colorado Springs, Colorado.

Each Long Range site consists of accommodation buildings, radar towers andradomes, generator and fuel systems, satellite terminals, automated weather station, andUHF andVHF ground-air-ground radio.^[1]: 17 Short Range sites consist of a single AN/FPS-124 radar, satellite terminals, power generation and fuel systems, and a small emergency shelter that can accommodate six people. Some short range stations lack weather stations and UHF Tactical Radios.^{[1]: 17–18, 24}

TheDistant Early Warning (DEW) Line, constructed in the late 1950s, was reaching obsolescence in the 1980s. With the signing of North American Air Defence Modernization agreement at the "Shamrock Summit" between Prime MinisterMulroney and PresidentReagan in Quebec City on 18 March 1985, the DEW Line began its eventual upgrading and transition becoming the North Warning System (NWS) of today.

The NWS began limited operation in 1988 with the commissioning and acceptance of the three newly constructed east coast sites BAF-3Brevoort Island,Nunavut, LAB-2Saglek and LAB-6Cartwright, both inLabrador. Throughout the late 1980s and early 1990s, new NWS LRR radars replaced former DEW Line sites. DEW sites that were not transitioned to North Warning operation were eventually closed down. The official activation of the NWS and inactivation of the DEW Line took place on 15 July 1993.

The bi-national North Warning System Office (NWSO) is located in Ottawa, Ontario and staffed with both Canadian and American military and civilian personnel. Staffed sites are operated by theRoyal Canadian Air Force, but physically staffed by civilian contractors. Logistical and maintenance support for the NWS is supplied by theAir Force Materiel Command of the United States Air Force, located atOgden Air Logistics Center (OO-ALC),Hill Air Force Base, Utah.

The former DEW Line sites were operated using practices and materials accepted by the environmental standards of the time. With their closure and many of them rebuilt as NWS sites, a clean-up project was undertaken to remove surplus infrastructure, treat chemically contaminated soils, and stabilize landfill sites. The clean-up was designed to keep chemical contamination from the DEW Line sites out of theArctic food chain, and ensure that the sites are restored to an environmentally safe condition. In 1989, the CanadianDepartment of National Defence (DND) started investigating the environmental conditions of the DEW Line sites and commenced clean-up work at two sites in 1996. The clean-up of 21 sites was scheduled to be completed in 2013. In March 2014 DND announced the remediation project was complete.

The NWS consists of 15 long-rangeradars (11 in Canada, of which eight were DEW Line sites) and 39 short-range radars (36 in Canada).^[2] The system forms a 4,800 km (2,983 mi) long and 320 km (199 mi) wide "tripwire" stretching from Alaska to southern Labrador. Minimally-attended NWS Long Range Radar AN/FPS-117 radar sites shaded in blue.

The following table lists the DEW Line sites not included in the NWS. Most of these sites not included were Intermediate sites closed in 1963 when they were declared obsolete. The stations consisted of a module train, a warehouse, a vehicle garage, anInuit house, POL (Petroleum,Oil,Lubricant) tanks and a continuous wave radar tower. Others were some Auxiliary sites that were replaced with new NWS stations. DEW Line stations in theAleutian Islands of Alaska were inactivated due to budget reductions in 1969. TheDYE Stations inGreenland andIceland were transferred to the USAFAir Forces Iceland in 1980.

The primary DEW line radars were theRaytheonAN/FPS-19 long range L-Band search radar in Canada and Alaska at main and auxiliary sites;BendixAN/FPS-30 at the four Greenland DYE radar stations.MotorolaAN/FPS-23 short range search radar was installed at the Intermediate sites, used as fillers to cover any Long Range Radar surveillance gaps.

• ^a Location approximate due to low-resolution aerial imagery of area.
• ^b Site location obliterated by snow cover.

• Canadian Forces base
• Joint Surveillance System
• NORAD Tracks Santa Program
• Operation Hurricane (Canada)

• Lackenbauer, Farish, Arthur-Lackenbauer (2005).The Distant Early Warning (DEW) Line: A Bibliography and Documentary Resource List.Archived from the original on 18 February 2022. Retrieved 18 June 2024. The Arctic Institute of North America.ISBN 1-894788-01-X .
• Contaminated Sites in NunavutArchived from the original on 8 July 2023. Retrieved 18 June 2024

• About NORAD Public information.
• PAIL Corp. Public information from PAIL Corp.
• Technical Radar Information NWS Radar information from FAS.

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