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Distant Early Warning Line

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153-524: The Distant Early Warning Line , also known as the DEW Line or Early Warning Line , was a system of radar stations in the northern Arctic region of Canada, with additional stations along the north coast and Aleutian Islands of Alaska (see Project Stretchout and Project Bluegrass ), in addition to the Faroe Islands , Greenland , and Iceland . It was set up to detect incoming bombers of

306-474: A Lockheed Martin contract "to upgrade all of the mission systems within Cheyenne Mountain, which included the space surveillance systems" for delivery in 2006. The portion of CCIC2S modernizing "attack warning systems within Cheyenne Mountain [was to] cost more than $ 700 million from fiscal years 2000 to 2006", and the delayed CCIC2S upgrades for space surveillance were superseded by systems for

459-470: A fractal surface, such as rocks or soil, and are used by navigation radars. A radar beam follows a linear path in vacuum but follows a somewhat curved path in atmosphere due to variation in the refractive index of air, which is called the radar horizon . Even when the beam is emitted parallel to the ground, the beam rises above the ground as the curvature of the Earth sinks below the horizon. Furthermore,

612-651: A skeleton crew and no longer operates on a 24/7 basis. The complex is on "warm standby", meaning it is only staffed when required. On the fiftieth anniversary of the NORAD agreement—May 12, 2008—the Command Center located within Cheyenne Mountain Complex was officially re-designated as the NORAD and USNORTHCOM Alternate Command Center. The Cheyenne Mountain Division of NORAD and USNORTHCOM

765-424: A transmitter that emits radio waves known as radar signals in predetermined directions. When these signals contact an object they are usually reflected or scattered in many directions, although some of them will be absorbed and penetrate into the target. Radar signals are reflected especially well by materials of considerable electrical conductivity —such as most metals, seawater , and wet ground. This makes

918-479: A $ 700 million contract with Raytheon to move systems into the complex to shield it from electromagnetic pulse attack, with additional work to be done at Vandenberg and Offutt . According to Gortney, "because of the very nature of the way that Cheyenne Mountain's built, it's EMP-hardened. And so, there's a lot of movement to put capability into Cheyenne Mountain and to be able to communicate in there". Electronic Systems Division Detachment 10 at Ent AFB became

1071-894: A Message Processing Subsystem and a Video Distribution Subsystem, and [to upgrade] the NORAD Computer System display capability and four major centers: (1) the Air Defense Operations Center , (2) the NORAD Command Center, (3) the Battle Staff Support Center, and (4) the Weather Support Unit." It was also to process and display " nuclear detection data provided from the Integrated Correlation and Display System." For $ 230 million

1224-499: A bad computer chip was updated, and staff and commander processes were improved to better respond to warnings. The Cheyenne Mountain Upgrade (CMU) of November 1988, designed to consolidate five improvement programs, was not installed because it was not compatible with other systems at Cheyenne Mountain and it did not meet the defined specifications according to deficiencies identified during testing. The five improvement programs were

1377-753: A bilateral agreement between the Canadian and United States governments, and by collaboration between the United States Department of Defense and the Bell System of communication companies. The DEW Line grew out of a detailed study made by a group of the nation's foremost scientists in 1952, the Summer Study Group at the Massachusetts Institute of Technology . The subject of the study was the vulnerability of

1530-523: A computer chip "went haywire" and issued false missile warnings, which raised the possibility that a nuclear war could be started accidentally, based upon incorrect data. Staff analyzed the data and found that the warnings were erroneous, and the systems were updated to identify false alarms. Gen. James V. Hartinger of the Air Force stated that "his primary responsibility is to provide Washington with what he calls 'timely, unambiguous, reliable warning' that

1683-482: A different dielectric constant or diamagnetic constant from the first, the waves will reflect or scatter from the boundary between the materials. This means that a solid object in air or in a vacuum , or a significant change in atomic density between the object and what is surrounding it, will usually scatter radar (radio) waves from its surface. This is particularly true for electrically conductive materials such as metal and carbon fibre, making radar well-suited to

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1836-743: A few years earlier on the Mid-Canada Line. The stations were interconnected by White Alice , a series of radio communications systems that used tropospheric scatter technology. For stations at the western end of the line, buildings at the deactivated Pet-4 United States Navy camp at Point Barrow were converted into workshops where prefabricated panels, fully insulated, were assembled to form modular building units 28 ft (8.5 m) long, 16 ft (4.9 m) wide, and 10 ft (3.0 m) high. These modules were put on sleds and drawn to station sites hundreds of miles away by powerful tractors. Each main station had its own airstrip – as close to

1989-540: A full radar system, that he called a telemobiloscope . It operated on a 50 cm wavelength and the pulsed radar signal was created via a spark-gap. His system already used the classic antenna setup of horn antenna with parabolic reflector and was presented to German military officials in practical tests in Cologne and Rotterdam harbour but was rejected. In 1915, Robert Watson-Watt used radio technology to provide advance warning of thunderstorms to airmen and during

2142-414: A limited nuclear attack, [and] a general nuclear attack." The least likely events are the most hazardous. There is more water produced by mountain springs than the base requires, and a 1,500,000-gallon (5,700,000-litre) reservoir ensures that even in event of fire, there is enough water to meet the facility's needs. A reservoir of 4,500,000 gallons (17,000,000 litres) of water is used as a heat sink. There

2295-874: A more military role began with a transition of authority, shifting responsibility of Arctic defence in Canada from the Royal Canadian Mounted Police to the Canadian Armed Forces. This "active defence" had three key elements: minimizing the extent of the American presence in the Canadian Arctic, Canadian government input into the management of the DEW Line, and full Canadian participation in Arctic defence. Funding problems for

2448-517: A more sophisticated radar system was constructed, the Ballistic Missile Early Warning System (BMEWS). The DEW Line was a significant achievement among Cold War initiatives in the Arctic. A successful combination of scientific design and logistical planning of the late 1950s, the DEW Line consisted of a string of continental defence radar installations, ultimately stretching from Alaska to Greenland. In addition to

2601-749: A physics instructor at the Imperial Russian Navy school in Kronstadt , developed an apparatus using a coherer tube for detecting distant lightning strikes. The next year, he added a spark-gap transmitter . In 1897, while testing this equipment for communicating between two ships in the Baltic Sea , he took note of an interference beat caused by the passage of a third vessel. In his report, Popov wrote that this phenomenon might be used for detecting objects, but he did nothing more with this observation. The German inventor Christian Hülsmeyer

2754-498: A proposal for further intensive research on radio-echo signals from moving targets to take place at NRL, where Taylor and Young were based at the time. Similarly, in the UK, L. S. Alder took out a secret provisional patent for Naval radar in 1928. W.A.S. Butement and P. E. Pollard developed a breadboard test unit, operating at 50 cm (600 MHz) and using pulsed modulation which gave successful laboratory results. In January 1931,

2907-732: A pulsed system, and the first such elementary apparatus was demonstrated in December 1934 by the American Robert M. Page , working at the Naval Research Laboratory . The following year, the United States Army successfully tested a primitive surface-to-surface radar to aim coastal battery searchlights at night. This design was followed by a pulsed system demonstrated in May 1935 by Rudolf Kühnhold and

3060-466: A raid on North America has begun." He explained that there are about 6,700 messages generated on average each hour in 1979 and 1980 and all had been processed without error. An off-site testing facility was established in Colorado Springs by NORAD in late 1979 or early 1980 so that system changes could be tested off-line before they were moved into production. Following another failure in 1980,

3213-442: A rescue. For similar reasons, objects intended to avoid detection will not have inside corners or surfaces and edges perpendicular to likely detection directions, which leads to "odd" looking stealth aircraft . These precautions do not totally eliminate reflection because of diffraction , especially at longer wavelengths. Half wavelength long wires or strips of conducting material, such as chaff , are very reflective but do not direct

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3366-459: A station chief, a cook, and a mechanic; and larger stations that had a variable number of employees and may have had libraries, forms of entertainment, and other accommodations. The stations used a number of long-range L band – emitting systems known as the AN/FPS-19. The "gaps" between the stations were watched by the directional AN/FPS-23 doppler radar systems, similar to those pioneered only

3519-404: A surface naval force of 12 radar picket destroyer escorts and 16 Guardian-class radar picket ships , and an air wing of Lockheed WV-2 Warning Star aircraft that patrolled the picket lines at an altitude of 1,000–2,000 m (3,300–6,600 ft) in 12- to 14-hour missions. Their objective was to extend early warning coverage against surprise Soviet bomber and missile attack as an extension of

3672-600: A system integrator and modernized the communications to a major data processing system, was completed in October 1972. The Ballistic Missile Defense Center (BMDC) BW 1.2 release was installed in February 1974 in the Combat Operations Center, under the command of CONAD. The Safeguard command and control system, operated by the commander, communicated warnings, observation data, and attack assessment to

3825-677: A system might do, Wilkins recalled the earlier report about aircraft causing radio interference. This revelation led to the Daventry Experiment of 26 February 1935, using a powerful BBC shortwave transmitter as the source and their GPO receiver setup in a field while a bomber flew around the site. When the plane was clearly detected, Hugh Dowding , the Air Member for Supply and Research , was very impressed with their system's potential and funds were immediately provided for further operational development. Watson-Watt's team patented

3978-563: A third line of radar stations (Distant Early Warning), this time running across the high Arctic. The line would run roughly along the 69th parallel north , about 320 km (200 mi) north of the Arctic Circle . Before this project was completed, men and women with the necessary knowledge, skills, and experience were drawn from Bell Telephone companies in every state in the United States, and many Canadian provinces. Much of

4131-556: A very successful first season hauling freight to the DEW Line. Later, military and civilian airlifts, huge sealifts during the short summers, barges contributed to the distribution of vast cargoes along the length of the Line to build the permanent settlements needed at each site. Much of the job of carrying mountains of supplies to the northern sites fell to military and naval units. More than 3,000 United States Army Transportation Corps soldiers were given special training to prepare them for

4284-514: A wide region and direct fighter aircraft towards targets. Marine radars are used to measure the bearing and distance of ships to prevent collision with other ships, to navigate, and to fix their position at sea when within range of shore or other fixed references such as islands, buoys, and lightships. In port or in harbour, vessel traffic service radar systems are used to monitor and regulate ship movements in busy waters. Meteorologists use radar to monitor precipitation and wind. It has become

4437-907: A writeup on the apparatus was entered in the Inventions Book maintained by the Royal Engineers. This is the first official record in Great Britain of the technology that was used in coastal defence and was incorporated into Chain Home as Chain Home (low) . Before the Second World War , researchers in the United Kingdom, France , Germany , Italy , Japan , the Netherlands , the Soviet Union , and

4590-494: Is a "massive" reservoir for diesel fuel and a "huge" battery bank with redundant power generators. The North American Air Defense Command (NORAD) was established and activated at the Ent Air Force Base on September 12, 1957. The Command is a binational organization of Canadian ( 1 Canadian Air Division ) and United States air defense command units, in accordance with NORAD Agreements first made on May 12, 1958. In

4743-413: Is a 99.999% degree of reliability of its electricity, water, air conditioning, power, and other support systems. The threats, in descending order of likelihood, that the complex may face are "medical emergencies, natural disasters, civil disorder, a conventional attack, an electromagnetic pulse attack, a cyber or information attack, chemical or biological or radiological attack, an improvised nuclear attack,

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4896-452: Is a simplification for transmission in a vacuum without interference. The propagation factor accounts for the effects of multipath and shadowing and depends on the details of the environment. In a real-world situation, pathloss effects are also considered. Frequency shift is caused by motion that changes the number of wavelengths between the reflector and the radar. This can degrade or enhance radar performance depending upon how it affects

5049-436: Is a system that uses radio waves to determine the distance ( ranging ), direction ( azimuth and elevation angles ), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track aircraft , ships , spacecraft , guided missiles , motor vehicles , map weather formations , and terrain . A radar system consists of a transmitter producing electromagnetic waves in

5202-444: Is also used by the nearby U.S. Civil Defense Warning Center. The complex was built under 2,000 feet (610 metres) of granite on five acres (2 hectares). Fifteen three-story buildings are protected from movement, e.g., earthquake or explosion, by a system of giant springs that the buildings sit on and flexible pipe connectors to limit the operational effect of movement. A total of more than 1,000 springs are designed to prevent any of

5355-451: Is as follows, where F D {\displaystyle F_{D}} is Doppler frequency, F T {\displaystyle F_{T}} is transmit frequency, V R {\displaystyle V_{R}} is radial velocity, and C {\displaystyle C} is the speed of light: Passive radar is applicable to electronic countermeasures and radio astronomy as follows: Only

5508-468: Is in the dome, flanked by two AN/FRC-45 lateral communications dishes (or AN/FRC-102, depending on the date). To the left are the much larger southbound AN/FRC-101 communications dishes. Not visible is the AN/FPS-23 "gap filler" doppler antenna. The DEW Line was upgraded with fifteen new AN/FPS-117 passive electronically scanned array radar systems between 1985 and 1994, and the line was then renamed

5661-567: Is intended. Radar relies on its own transmissions rather than light from the Sun or the Moon, or from electromagnetic waves emitted by the target objects themselves, such as infrared radiation (heat). This process of directing artificial radio waves towards objects is called illumination , although radio waves are invisible to the human eye as well as optical cameras. If electromagnetic waves travelling through one material meet another material, having

5814-608: Is maintained by the 21st Mission Support Group which provides support and maintenance for the 'NORAD/USNORTHCOM's training, exercise and alternate command center functions, U.S. Strategic Command's Missile Warning Center, Detachment 2 of the 17th Test Squadron, Air Force Technical Applications Center's research laboratory, the Defense Intelligence Agency's Western Continental United States Regional Service Center'. Cheyenne Mountain Air Force Station

5967-590: Is owned and operated by Air Force Space Command. NORAD and USNORTHCOM now use just under 30% of the floor space within the complex and comprise approximately 5% of the daily population at Cheyenne Mountain. The Cheyenne Mountain Complex serves as NORAD and USNORTHCOM's Alternate Command Center and as a training site for crew qualification. Day-to-day crew operations for NORAD and USNORTHCOM typically take place at Peterson Air Force Base. In early 2015, Admiral William E. Gortney , commander of NORAD and NORTHCOM, announced

6120-417: Is the range. This yields: This shows that the received power declines as the fourth power of the range, which means that the received power from distant targets is relatively very small. Additional filtering and pulse integration modifies the radar equation slightly for pulse-Doppler radar performance , which can be used to increase detection range and reduce transmit power. The equation above with F = 1

6273-1043: The AN/FPS-129 HAVE STARE (Globus II) radar in California had been upgraded to "relay data to Cheyenne Mountain", and by October 1995 the 1st Command and Control Squadron (1CACS) in the bunker was providing space collision avoidance data to the Cheyenne Mountain Operations Center's space control center. In June 1993, the Cheyenne Mountain Complex Operations Center had the USSPACE and NORAD Command Center, NORAD Air Defense Operations Center (ADOC), NORAD/USSPACECOM Combined Intelligence Watch Center (CIWC), USSPACECOM Space Defense Operations Center (SPADOC), USSPACECOM Space Surveillance Center (SSC), AFSPACECOM Weather Operations Center, and

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6426-532: The Aleutian Island chain) and back, non-stop. Its orbits overlapped the radar picket stations of the ships of Escort Squadron Seven (CORTRON SEVEN), from roughly Kodiak Island to the Midway Atoll and Escort Squadron Five (CORTRON FIVE), from Pearl Harbor to northern Pacific waters. Normally four or five WV-2s were required at any single time to provide coverage over the entire line. This coverage

6579-492: The Cold War to give early warning of a Soviet nuclear strike , to allow time for United States bombers to get off the ground and land-based intercontinental ballistic missile (ICBMs) to be launched, to reduce the chances that a preemptive strike could destroy the United States' strategic nuclear forces. The original DEW line was designed to detect bombers and was unable to detect ICBMs. To give warning of this threat, in 1958

6732-637: The Joint Space Operations Center 's Space C2 program and Integrated Space Situational Awareness program. By 2003, consoles for the Ground-Based Mid-Course Defense (GMD) had been contracted for Cheyenne Mountain, and the planned 18 month Cheyenne Mountain Realignment to move Command Center operations to Peterson AFB was complete by May 13, 2008. On August 3, 2011, a ribbon cutting was held for

6885-718: The National Civil Defense Warning Center was in the bunker. System Development Corporation updated Air Defense Command satellite information processing systems for $ 15,850,542 on January 19, 1973. The improvements were primarily to the Space Computational Center's displays and application software, which was updated to provide real-time positioning of orbiting space systems for the NORAD Combat Operation Center. The first phase, which established

7038-628: The Nyquist frequency , since the returned frequency otherwise cannot be distinguished from shifting of a harmonic frequency above or below, thus requiring: Or when substituting with F D {\displaystyle F_{D}} : As an example, a Doppler weather radar with a pulse rate of 2 kHz and transmit frequency of 1 GHz can reliably measure weather speed up to at most 150 m/s (340 mph), thus cannot reliably determine radial velocity of aircraft moving 1,000 m/s (2,200 mph). In all electromagnetic radiation ,

7191-717: The RAF's Pathfinder . The information provided by radar includes the bearing and range (and therefore position) of the object from the radar scanner. It is thus used in many different fields where the need for such positioning is crucial. The first use of radar was for military purposes: to locate air, ground and sea targets. This evolved in the civilian field into applications for aircraft, ships, and automobiles. In aviation , aircraft can be equipped with radar devices that warn of aircraft or other obstacles in or approaching their path, display weather information, and give accurate altitude readings. The first commercial device fitted to aircraft

7344-595: The Soviet Union during the Cold War , and provide early warning of any sea-and-land invasion. The DEW Line was the northernmost and most capable of three radar lines in Canada and Alaska. The first of these was the joint Canadian-United States Pinetree Line , which ran from Newfoundland to Vancouver Island just north of the Canada–United States border , but even while it was being built there were concerns that it would not provide enough warning time to launch an effective counterattack. The Mid-Canada Line (MCL)

7497-763: The United States Federal Government authorized construction of the Ballistic Missile Early Warning System (BMEWS), at a reported cost of $ 28 billion. In 1985, it was decided that the more capable of the DEW Line stations were to be upgraded with the GE AN/FPS-117 radar systems and merged with newly built stations into the North Warning System. Their automation was increased and a number of additional stations were closed. This upgrading

7650-731: The caribou , as well as non-seasonal hunting. These aspects are claimed to have had a devastating impact on the local native subsistence economies and environment. The DEW line was supplemented by the Contiguous Radar Coverage System , which included two "barrier" forces in the Atlantic and the Pacific oceans which were operated by the United States Navy from 1956 to 1965. These barrier forces consisted of surface picket stations, dubbed " Texas Towers ",

7803-440: The electromagnetic spectrum . One example is lidar , which uses predominantly infrared light from lasers rather than radio waves. With the emergence of driverless vehicles, radar is expected to assist the automated platform to monitor its environment, thus preventing unwanted incidents. As early as 1886, German physicist Heinrich Hertz showed that radio waves could be reflected from solid objects. In 1895, Alexander Popov ,

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7956-497: The mutual assured destruction (MAD) philosophy. However, the scenario of a coordinated airborne invasion coupled with a limited nuclear strike was the real threat that this line protected against. It did so by providing Distant Early Warning of an inbound aerial invasion force, which would have to appear at the far north hours ahead of any warhead launches in order to be coordinated well enough to prevent MAD. A number of intermediate stations were decommissioned, since their effectiveness

8109-460: The radio or microwaves domain, a transmitting antenna , a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in

8262-407: The reflective surfaces . A corner reflector consists of three flat surfaces meeting like the inside corner of a cube. The structure will reflect waves entering its opening directly back to the source. They are commonly used as radar reflectors to make otherwise difficult-to-detect objects easier to detect. Corner reflectors on boats, for example, make them more detectable to avoid collision or during

8415-791: The " Joint Task Force – Cheyenne Mountain Operations organization was brought online to take responsibility for the installation", Brig. Gen. Donald Peterson was the commander of the JTF, which was renamed the " U.S. Space Command Cheyenne Mountain operations center" by March 1995. On July 28, 2006, the Cheyenne Mountain Realignment redesignated the Cheyenne Mountain Directorate to the Cheyenne Mountain Division. Circa 2004

8568-534: The "new boy" Arnold Frederic Wilkins to conduct an extensive review of available shortwave units. Wilkins would select a General Post Office model after noting its manual's description of a "fading" effect (the common term for interference at the time) when aircraft flew overhead. By placing a transmitter and receiver on opposite sides of the Potomac River in 1922, U.S. Navy researchers A. Hoyt Taylor and Leo C. Young discovered that ships passing through

8721-420: The 15 buildings from shifting more than one inch. The complex is the only underground Department of Defense facility certified to be able to sustain a high-altitude electromagnetic pulse (EMP). There are a large quantity of cots for most of the personnel, including suites for high-ranking officers within the bunker. Amenities include a medical facility, store, cafeteria, and fitness centers inside and outside

8874-413: The 1920s went on to lead the U.K. research establishment to make many advances using radio techniques, including the probing of the ionosphere and the detection of lightning at long distances. Through his lightning experiments, Watson-Watt became an expert on the use of radio direction finding before turning his inquiry to shortwave transmission. Requiring a suitable receiver for such studies, he told

9027-825: The 1970s. In 1979, the Cheyenne Mountain Complex Improvements Program 427M system became fully operational. It was a consolidated Cheyenne Mountain Upgrade program for command center, space, ballistic missile, and space functions, developed using new software technology and designed for computers with large processing capacity. There were three major segments of the 427M system: the Communication System Segment (CSS), NORAD Computer System (NCS), and Space Computational Center (SCC). The 425L Command and Control System, Display Information Processor, Command Center Processing System, and other hardware were replaced by

9180-545: The AFSPACECOM Systems Center within its facility. Plans to house the USSPACECOM and NORAD command centers in the same location began by July 1994. A $ 450 million upgrade was made to the missile warning center beginning in February 1995. The effort was part of a $ 1.7 billion renovation program for Cheyenne Mountain. 'Granite Sentry' was an improvement program for the complex. It aimed "to provide

9333-486: The Battle Staff Support Center. The Space Defense Operations Center (SPADOC), established on October 1, 1979, consolidated United States Air Force satellite survivability, space surveillance, and US ASAT operations into one wartime space activities hub at the NORAD Cheyenne Mountain Complex. Space surveillance and missile warning functions were performed by the Core Processing Segment (CPS) using Worldwide Military Command and Control System 's Honeywell H6080 computers at

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9486-645: The CCPDS Replacement (CCPDS-R), CSS Replacement (CSS-R), Granite Sentry upgrade, SCIS, and SPADOC 4. SPADOC 4 was for upgrading the SCC with primary and backup 3090-200J mainframes ), and SPADOC 4 block A achieved initial operating capability (IOC) in April 1989. The CSS-R "first element" achieved IOC on April 12, 1991; and the 427M system was replaced c.  1992 . The CSSR, SCIS, Granite Sentry, CCPDS-R, and their interfaces were tested in 1997. Testing of Granite Sentry nuclear detonation (NUDET) data processing system found it to be inadequate. The Joint Surveillance System (JSS), developed under an agreement with

9639-416: The Canadian government, became fully operational in seven Region Operations Control Centers (ROCCs) on December 23, 1983. The Joint Surveillance System was implemented to replace Semi-Automatic Ground Environment (SAGE). In 1986, Congress approved development of the Survivable Communications Integration System (SCIS) to communicate missile warning messages simultaneously over many forms of media, but it

9792-430: The Cheyenne Mountain Complex Management Office (CMCMO) in 1963, the year the Chidlaw Combined Operations Center began operations; and on February 15, 1980, ESD Detachment 2 was established at the "Cheyenne Mountain Complex" (Det 2 became the AFSC focal point during the Cheyenne Mountain Upgrade.) Aerospace Defense Command organizations in the bunker became a specified command when the major command ended in 1980; e.g.,

9945-500: The Combat Operations Center. It was also designed to release nuclear weapons. By 1978, five operating centers and a command post resided within the NORAD Combat Operations Center. The Space Computational Center catalogued and tracked space objects. The Intelligence Center analyzed intelligence data. Data was consolidated and displayed in the Command Post by the System Center. The Weather Support Unit monitored local and global weather patterns. The NORAD Commander's wartime staff reported to

10098-581: The DEW Line also played a role in perception of the project. American investment in building and operating the DEW Line system declined as the ICBM threat refocused priorities, but Canada did not fill the void with commensurate additional funding. In 1968 a Canadian Department of National Defence Paper (27 November 1968) stated no further funding for research on the DEW Line or air space would be allocated due in part to lack of commercial activity The Canadian Government also limited United States air activity, base activity, soldier numbers, and contractor numbers; and

10251-459: The DEW Line provided some economic development for the Arctic region. This provided momentum for further development through research, new communications, and new studies of the area. Although the construction of the DEW line itself was placed in American hands, much of the later development was under direct Canadian direction. Resource protection of historical DEW Line sites is currently under discussion in Canada and Alaska. The discussion stems from

10404-435: The DEW Line. The Atlantic Barrier (BarLant) consisted of two rotating squadrons, one based at Naval Station Argentia , Newfoundland , to fly orbits to the Lajes Field in the Azores and back; and the other at Naval Air Station Patuxent River , Maryland. BarLant began operations on 1 July 1956, and flew continuous coverage until early 1965, when the barrier was shifted to cover the approaches between Greenland, Iceland, and

10557-431: The J31 unit of HQ NORAD/ADCOM subsequently staffed the Space Surveillance Center in the same room as the Missile Warning Center (separated by partitions). The "HQ Cheyenne Mountain Support Group ... was activated at the Cheyenne Mountain Complex" in October 1981 to support the Aerospace Defense Center 's operation of the NORAD combat operations center". In 1983 the Foreign Technology Division had an operating location at

10710-405: The January 2010 – June 30, 2011, Missile Warning Center renovation funded by USSTRATCOM . Over the years, the installation came to house elements of the North American Aerospace Defense Command (NORAD), U.S. Strategic Command , U.S. Air Force Space Command and U.S. Northern Command (USNORTHCOM). Under what became known as the Cheyenne Mountain Operations Center (CMOC), several centers supported

10863-412: The NORAD Computer System (NCS). The new system was designed to centralize several databases, improve on-line display capabilities, and consolidate mission warning information processing and transmission. It was intended to have greater reliability and quicker early warning capability. The Command Center Processing System's original UNIVAC 1106 , re-purposed for Mission Essential Back-up Capability (MEBU),

11016-516: The NORAD missions of aerospace warning and aerospace control and provided warning of ballistic missile or air attacks against North America. On July 28, 2006, the Cheyenne Mountain Directorate was re-designated as the Cheyenne Mountain Division , with the mission to assist in establishing an integrated NORAD and USNORTHCOM Command Center within the headquarters building at Peterson Air Force Base . The Unified Space Vault and

11169-436: The North Warning System. Average power output 400 watts Modifications to each operating radar station occurred during the construction phase of the DEW Line system. This was due to the extreme winds, frigid temperatures, and the ground conditions due to permafrost and ice. There were two significant electronic modifications that were also crucial to the functioning of these radar stations in an Arctic environment. One reduced

11322-611: The SPADOC Computational Center (SCC) and NORAD Computer System (NCS). A third computer was operational backup for SCC or NCS. By 1981, the H6080 failed to meet the requirements for timely computations. SPADATS was deactivated about 1980, although some of its logic continued on in SPADOC systems. NORAD had a series of warning and assessment systems that were not fully automated in the Cheyenne Mountain complex into

11475-531: The Space Control Center were moved from Cheyenne Mountain to the Joint Space Operations Center at Vandenberg Air Force Base about October 2007. In 2006, NORAD relocated to a basement in the Peterson No. 2 building at the nearby Peterson AFB . Northern Command and Space Command and Canadian military defense partners relocated at Peterson. The Cheyenne Mountain complex is maintained by

11628-580: The USSC have been based at Peterson Space Force Base and the complex, re-designated as an Air Force station, is used for crew training and as a back-up command center if required. The military complex has included, in the past, many units of NORAD, USSC, Aerospace Defense Command (ADCOM), Air Force Systems Command , Air Weather Service, and the Federal Emergency Management Agency (FEMA). The complex's communication center

11781-434: The United Kingdom ( GIUK barrier ). Aircraft from Argentia were staged through Naval Air Station Keflavik , Iceland, to extend coverage times. The Pacific Barrier (BarPac) began operations with one squadron operating from Naval Air Station Barbers Point , Hawaii, and a forward refuelling base at Naval Air Facility Midway Island , on 1 July 1958. Planes flew from Midway Island to Naval Air Facility Adak on Adak Island (in

11934-452: The United States and Canada over the cleanup of deactivated Canadian DEW Line sites. The cleanup is now underway, site by site. In assessing the cleanup, new research suggests that off-road vehicles damaged vegetation and organic matter, resulting in the melting of the permafrost, a key component to the hydrological systems of the areas. The DEW Line has also been linked to depleted fish stocks and carelessness in agitating local animals such as

12087-642: The United States and Canada to aerial bombing attacks, and its concluding recommendation was that a distant early warning line of search radar stations be built across the Arctic region of the North American continent as rapidly as possible. Improvements in Soviet technology rendered the Pinetree Line and Mid-Canada Line inadequate to provide enough early warning and on 15 February 1954, the Canadian and United States governments agreed to jointly build

12240-437: The United States and southern Canada worked on the project. Concrete was poured in the middle of Arctic winters, buildings were constructed, electrical service, heating, and fresh water were provided, huge steel antenna towers were erected, airstrips and hangars were built, putting it all together in darkness, blizzards, and subzero temperatures. After the buildings came the installation of radar and communications equipment, then

12393-724: The United States, independently and in great secrecy, developed technologies that led to the modern version of radar. Australia, Canada, New Zealand, and South Africa followed prewar Great Britain's radar development, Hungary and Sweden generated its radar technology during the war. In France in 1934, following systematic studies on the split-anode magnetron , the research branch of the Compagnie générale de la télégraphie sans fil (CSF) headed by Maurice Ponte with Henri Gutton, Sylvain Berline and M. Hugon, began developing an obstacle-locating radio apparatus, aspects of which were installed on

12546-682: The activities of several tenant units. Also located in Colorado Springs is Peterson Space Force Base , where the North American Aerospace Defense Command (NORAD) and United States Northern Command (USNORTHCOM) headquarters are located. Formerly the center for the United States Space Command (USSC) and NORAD, the Complex monitored the airspace of Canada and the United States for missiles, space systems, and foreign aircraft through its worldwide early-warning system. Since 2008, NORAD and

12699-418: The area – first from the air and then on the ground – to locate by scientific means the best sites for the main, auxiliary, and intermediate stations. These crews lived and worked under primitive conditions. They covered vast distances by airplanes, snowmobiles , and dog sleds , working in blinding snowstorms with temperatures so low that ordinary thermometers could not measure them. They completed their part of

12852-537: The arrest of Oshchepkov and his subsequent gulag sentence. In total, only 607 Redut stations were produced during the war. The first Russian airborne radar, Gneiss-2 , entered into service in June 1943 on Pe-2 dive bombers. More than 230 Gneiss-2 stations were produced by the end of 1944. The French and Soviet systems, however, featured continuous-wave operation that did not provide the full performance ultimately synonymous with modern radar systems. Full radar evolved as

13005-479: The beam path caused the received signal to fade in and out. Taylor submitted a report, suggesting that this phenomenon might be used to detect the presence of ships in low visibility, but the Navy did not immediately continue the work. Eight years later, Lawrence A. Hyland at the Naval Research Laboratory (NRL) observed similar fading effects from passing aircraft; this revelation led to a patent application as well as

13158-494: The beginning of the development of the DEW Line idea, Canadian concerns over political perception grew enormously. Noted Canadian Arctic historian P. Whitney Lackenbauer argues that the Canadian Government saw little intrinsic value in the Arctic, but due to fear of Americanization and American penetration into the Canadian Arctic, brought significant changes and a more militaristic role to the north. This shift into

13311-422: The buildings as safety regulations and the terrain permitted. Service buildings, garages, connecting roads, storage tanks, and perhaps an aircraft hangar completed the community. Drifting snow was a constant menace. Siting engineers and advance parties learned this the hard way when their tents disappeared beneath the snow in a few hours. The permanent H-shaped buildings at the main stations were always pointed into

13464-400: The bulk of this work under the direction of Western Electric engineers. Huge quantities of gravel were produced and moved. The construction work needed to build housing, airstrips, aircraft hangars , outdoor and covered antennas , and antenna towers was done by subcontractors. In all, over 7,000 bulldozer operators, carpenters, masons, plumbers, welders, electricians, and other tradesmen from

13617-573: The bunker and in 1992, an airman of the "1010th Civil Engineering Squadron at Cheyenne Mountain Air Force Base" developed a 3-D AutoCAD model of the bunker "to zoom in on a specific room". By 1995 a "missile operations section" supported the missile warning center, and in 2001 the 1989 1CACS at the Cheyenne Mountain Air Force Station was renamed the 1st Space Control Squadron . On June 24, 1994, when

13770-417: The construction was carried out in a massive logistical operation that took place mostly during the summer months when the sites could be reached by ships. The 63-base line reached operational status in 1957. The MCL was shut down in the early 1960s, and much of the Pinetree Line was given over to civilian use. In 1985, as part of the " Shamrock Summit ", the United States and Canada agreed to transition DEW to

13923-435: The deactivation aspect of the sites and arguments over what to do with leftover equipment and leftover intact sites. Many Canadian historians encourage the preservation of DEW Line sites through heritage designations. The DEW Line is a setting for the 1957 film The Deadly Mantis . The film begins with a short documentary on the three RADAR lines, focusing on the DEW Line's construction. A controversy also developed between

14076-408: The detection of aircraft and ships. Radar absorbing material , containing resistive and sometimes magnetic substances, is used on military vehicles to reduce radar reflection . This is the radio equivalent of painting something a dark colour so that it cannot be seen by the eye at night. Radar waves scatter in a variety of ways depending on the size (wavelength) of the radio wave and the shape of

14229-476: The detection process. As an example, moving target indication can interact with Doppler to produce signal cancellation at certain radial velocities, which degrades performance. Sea-based radar systems, semi-active radar homing , active radar homing , weather radar , military aircraft, and radar astronomy rely on the Doppler effect to enhance performance. This produces information about target velocity during

14382-411: The detection process. This also allows small objects to be detected in an environment containing much larger nearby slow moving objects. Doppler shift depends upon whether the radar configuration is active or passive. Active radar transmits a signal that is reflected back to the receiver. Passive radar depends upon the object sending a signal to the receiver. The Doppler frequency shift for active radar

14535-626: The device in patent GB593017. Development of radar greatly expanded on 1 September 1936, when Watson-Watt became superintendent of a new establishment under the British Air Ministry , Bawdsey Research Station located in Bawdsey Manor , near Felixstowe, Suffolk. Work there resulted in the design and installation of aircraft detection and tracking stations called " Chain Home " along the East and South coasts of England in time for

14688-432: The effects of vibration in correlation to temperature change, the other increased the pulse duration from two to six microseconds. It also began using a crystal oscillator for more stable readings and accurate accounts of movement within the air. There were three types of stations: small unstaffed "gap filler stations" that were checked by ground crews only every few months during the summer; intermediate stations with only

14841-538: The electric field is perpendicular to the direction of propagation, and the electric field direction is the polarization of the wave. For a transmitted radar signal, the polarization can be controlled to yield different effects. Radars use horizontal, vertical, linear, and circular polarization to detect different types of reflections. For example, circular polarization is used to minimize the interference caused by rain. Linear polarization returns usually indicate metal surfaces. Random polarization returns usually indicate

14994-473: The entire area in front of it, and then used one of Watson-Watt's own radio direction finders to determine the direction of the returned echoes. This fact meant CH transmitters had to be much more powerful and have better antennas than competing systems but allowed its rapid introduction using existing technologies. A key development was the cavity magnetron in the UK, which allowed the creation of relatively small systems with sub-meter resolution. Britain shared

15147-613: The final improved designs of all facilities and final plans for manpower, transportation, and supply. With the experimental phase completed successfully, the Air Forces asked the Western Electric Company to proceed as rapidly as possible with the construction of the entire DEW Line. That was in December 1954, before the route to be followed in the eastern section had even been determined. The locations were surveyed out by John Anderson-Thompson . Siting crews covered

15300-466: The firm GEMA  [ de ] in Germany and then another in June 1935 by an Air Ministry team led by Robert Watson-Watt in Great Britain. In 1935, Watson-Watt was asked to judge recent reports of a German radio-based death ray and turned the request over to Wilkins. Wilkins returned a set of calculations demonstrating the system was basically impossible. When Watson-Watt then asked what such

15453-477: The information on to the DEW Line. If an unknown flight was detected, the DEW Line station would contact AMIS to see if a flight plan might have been missed; if not, NORAD was notified. Military flights, including B-52 bombers, frequently operated in the polar regions and used identification friend or foe (IFF) systems to authenticate the flight. The early warning provided was useless against ICBMs and submarine -launched attacks. These were countered and tempered by

15606-599: The instantaneous (one-millionth of a second) evaluation of aerospace surveillance data. The Space Defense Center moved from Ent AFB to the complex in 1965. The NORAD Combat Operations Center was fully operational April 20, 1966 and The Space Defense Command's 1st Aerospace Control Squadron moved to Cheyenne Mountain that month. The following systems or commands became operational between May and October, 1966: The NORAD Attack Warning System, Combat Operations Command, and Delta I computer system, which recorded and monitored every detected space system. By January 4, 1967,

15759-524: The job of unloading ships in the Arctic . They went with the convoys of United States Navy ships and they raced time during the few weeks the ice was open to land supplies at dozens of spots on the shores of the Arctic Ocean during the summers of 1955, 1956, and 1957. Scores of military and commercial pilots, flying everything from small bush planes to four-engined turboprops , were the backbone of

15912-591: The job on schedule and set the stage for the crews and machines that followed. The line consisted of 63 stations stretching from Alaska to Baffin Island , covering nearly 10,000 km (6,200 mi). The United States agreed to pay for and construct the line, and to employ Canadian labour as much as possible. A target date for completing the DEW Line and having it in operation was set for 31 July 1957. This provided only two short Arctic summers adding up to about six months in which to work under passable conditions. Much of

16065-626: The late 1950s, a plan was developed to construct a command and control center in a hardened facility as a Cold War defensive strategy against long-range Soviet bombers, ballistic missiles, and a nuclear attack. In 1957, the Strategic Air Command began construction in New England inside Bare Mountain for a hardened bunker to contain the command post for the 8th Air Force , which was located at nearby Westover Air Force Base , Chicopee, Massachusetts . This underground facility

16218-407: The line became a cornerstone of the new North American Aerospace Defense Command (NORAD) organization of joint continental air defence . USAF personnel were limited to the main stations for each sector and they performed annual inspections of auxiliary and intermediate stations as part of the contract administration. Most operations were performed by Canadian and United States civilian personnel, and

16371-474: The military complex are the parking lots, a fire station, and outdoor recreational facilities. The recreational amenities include Mountain Man Park, picnic areas, a racquetball facility, softball field, sand volleyball court, basketball court, a putting green, and horseshoe area. The complex has its own power plant, heating and cooling system, and water supply. The 21st Mission Support Group ensures there

16524-706: The most hostile and isolated environments in North America. The construction project employed about 25,000 people. Western Electric and Alaska Freightlines, with the help of the United States Army Transportation Research and Development Command (TRADCOM), contracted to have a pair of off-road overland trains , the TC-264 Sno-Buggy, designed specifically for Arctic conditions, to be built by LeTourneau Technologies , owned by R. G. LeTourneau . The TC-264 Sno-Buggy

16677-530: The mountain. The bunker is built to deflect a 30 megaton nuclear explosion as close as 1.2 miles (1.9 km). Within a mountain tunnel are sets of 25-ton blast doors and another for the civil engineering department. The doors were built so that they can always be opened when needed. Should a nuclear blast hit the building, they are designed to withstand a blast wave . There is a network of blast valves with unique filters to capture airborne chemical, biological, radiological, and nuclear contaminants. Outside of

16830-468: The new North Warning System (NWS). Beginning in 1988, most of the original DEW stations were deactivated, while a small number were upgraded with all-new equipment. The official handover from DEW to NWS took place on 15 July 1993. The shortest, or great circle , route for a Soviet air attack on North America was through the Arctic, across the area around the North Pole . The DEW Line was built during

16983-481: The north where they would offer hours of advance warning. This would not only provide ample time for the defences to prepare, but also allow the Strategic Air Command to get its active aircraft airborne long before Soviet bombers could reach their targets. The need was considered critical and the construction was given the highest national priorities. Advance site preparation began in December 1954, and

17136-508: The ocean liner Normandie in 1935. During the same period, Soviet military engineer P.K. Oshchepkov , in collaboration with the Leningrad Electrotechnical Institute , produced an experimental apparatus, RAPID, capable of detecting an aircraft within 3 km of a receiver. The Soviets produced their first mass production radars RUS-1 and RUS-2 Redut in 1939 but further development was slowed following

17289-411: The only means of access to many of the stations during the wintertime. In all, 460,000 short tons (420,000 t; 410,000 long tons) of materials were moved from the United States and southern Canada to the Arctic by air, land, and sea. As the stacks of materials at the station sites mounted, construction went ahead rapidly. Subcontractors with a flair for tackling difficult construction projects handled

17442-743: The operation. The Lockheed LC-130 , a ski-equipped version of the C-130 Hercules , owned by the United States Air Force and operated by the 139th Airlift Squadron , provided a significant amount of airlift to sites that were out on ice caps such as Dye 3 in Greenland. Transport planes such as the C-124 Globemaster and the C-119 Flying Boxcar also supported the project. Together, these provided

17595-608: The operations were automated as much as was possible at the time. All of the installations flew both the Canadian and United States flags until they were deactivated as DEW sites and sole jurisdiction was given to the Government of Canada as part of the North Warning System in the late 1980s and early 1990s. The Point Lay, Alaska DEW line station has a typical suite of systems. The main AN/FPS-19 search radar

17748-531: The outbreak of World War II in 1939. This system provided the vital advance information that helped the Royal Air Force win the Battle of Britain ; without it, significant numbers of fighter aircraft, which Great Britain did not have available, would always have needed to be in the air to respond quickly. The radar formed part of the " Dowding system " for collecting reports of enemy aircraft and coordinating

17901-518: The overall operation would be considered and called in all formalities a "joint operation". The cultural impact of the DEW Line System is immense and significant to the heritage of Canada and Alaska. In Canada, the DEW line increased connections between the populous south and the remote High Arctic, helping to bring Inuit more thoroughly into the Canadian polity. The construction and operating of

18054-1370: The period before and during World War II . A key development was the cavity magnetron in the United Kingdom , which allowed the creation of relatively small systems with sub-meter resolution. The term RADAR was coined in 1940 by the United States Navy as an acronym for "radio detection and ranging". The term radar has since entered English and other languages as an anacronym , a common noun, losing all capitalization . The modern uses of radar are highly diverse, including air and terrestrial traffic control, radar astronomy , air-defense systems , anti-missile systems , marine radars to locate landmarks and other ships, aircraft anti-collision systems, ocean surveillance systems, outer space surveillance and rendezvous systems, meteorological precipitation monitoring, radar remote sensing , altimetry and flight control systems , guided missile target locating systems, self-driving cars , and ground-penetrating radar for geological observations. Modern high tech radar systems use digital signal processing and machine learning and are capable of extracting useful information from very high noise levels. Other systems which are similar to radar make use of other parts of

18207-554: The prevailing winds and their bridges built high off the ground. The Arctic region was frequently transited by commercial aircraft on polar routes , either flying between Europe and western North America, or between Europe and Asia using Alaska as a stopover. These flights would penetrate the DEW Line. To differentiate these commercial flights from Soviet bombers, the flight crews had to transmit their flight plan to an Air Movement Identification System (AMIS) centre at either Goose Bay , Edmonton , or Anchorage . These stations then passed

18360-706: The primary tool for short-term weather forecasting and watching for severe weather such as thunderstorms , tornadoes , winter storms , precipitation types, etc. Geologists use specialized ground-penetrating radars to map the composition of Earth's crust . Police forces use radar guns to monitor vehicle speeds on the roads. Automotive radars are used for adaptive cruise control and emergency breaking on vehicles by ignoring stationary roadside objects that could cause incorrect brake application and instead measuring moving objects to prevent collision with other vehicles. As part of Intelligent Transport Systems , fixed-position stopped vehicle detection (SVD) radars are mounted on

18513-677: The program was also to "replace display screens of the Attack Warning and Attack Assessment System." It was delayed from 1993 to 1996. Granite Sentry and other Cheyenne Mountain Upgrade interfaces were tested in 1997, and Granite Sentry's processing regarding "simulated [nuclear] detonation messages…injected into the Defense Support Program Data Distribution Center [was] not adequate...". The Combatant Commander's Integrated Command and Control System (CCIC2S) program began in 2000 with

18666-432: The radial component of the velocity is relevant. When the reflector is moving at right angle to the radar beam, it has no relative velocity. Objects moving parallel to the radar beam produce the maximum Doppler frequency shift. When the transmit frequency ( F T {\displaystyle F_{T}} ) is pulsed, using a pulse repeat frequency of F R {\displaystyle F_{R}} ,

18819-414: The response. Given all required funding and development support, the team produced working radar systems in 1935 and began deployment. By 1936, the first five Chain Home (CH) systems were operational and by 1940 stretched across the entire UK including Northern Ireland. Even by standards of the era, CH was crude; instead of broadcasting and receiving from an aimed antenna, CH broadcast a signal floodlighting

18972-589: The responsibility was delegated under close supervision to a vast number of subcontractors, suppliers, and United States military units. The initial contract with the United States Air Force and the Royal Canadian Air Force provided for the design and construction of a small experimental system to determine at the beginning whether the idea was practicable. The designs of communication and radar detection equipment available at

19125-410: The resulting frequency spectrum will contain harmonic frequencies above and below F T {\displaystyle F_{T}} with a distance of F R {\displaystyle F_{R}} . As a result, the Doppler measurement is only non-ambiguous if the Doppler frequency shift is less than half of F R {\displaystyle F_{R}} , called

19278-427: The roadside to detect stranded vehicles, obstructions and debris by inverting the automotive radar approach and ignoring moving objects. Smaller radar systems are used to detect human movement . Examples are breathing pattern detection for sleep monitoring and hand and finger gesture detection for computer interaction. Automatic door opening, light activation and intruder sensing are also common. A radar system has

19431-407: The scattered energy back toward the source. The extent to which an object reflects or scatters radio waves is called its radar cross-section . The power P r returning to the receiving antenna is given by the equation: where In the common case where the transmitter and the receiver are at the same location, R t = R r and the term R t ² R r ² can be replaced by R , where R

19584-477: The secondary Mid-Canada Line and the tertiary Pinetree Line , the DEW Line marked the edge of an electronic grid controlled by the new Semi-Automatic Ground Environment (SAGE) computer system and was ultimately centred at the Cheyenne Mountain Complex , Colorado , command hub of the North American Aerospace Defense Command (NORAD). The construction of the DEW Line was made possible by

19737-644: The signal is attenuated by the medium the beam crosses, and the beam disperses. The maximum range of conventional radar can be limited by a number of factors: Cheyenne Mountain Complex The Cheyenne Mountain Complex is a United States Space Force installation and defensive bunker located in unincorporated El Paso County, Colorado , next to the city of Colorado Springs , at the Cheyenne Mountain Space Force Station , which hosts

19890-512: The surplus included sixty equipped wannigans - enough to permit setup of field camps at all construction sites. (A "wannigan" is a building on sleds, about 12 x 20 feet in size. These were completely equipped for camp operations and were of various types - Cook, Mess, Bunk, Power Plant, Water, Shop, Storage, Utility, Steam Point, etc.) Prototypes of several stations were designed and built in Alaska in 1953. A prototype built for training purposes

20043-702: The system coverage was expanded even further: see Project Stretchout and Project Bluegrass . The majority of Canadian DEW Line stations were the joint responsibility of the Royal Canadian Air Force (the Canadian Armed Forces ) and the United States Air Force. The USAF component was the 64th Air Division , Air Defense Command . The 4601st Support Squadron, based in Paramus, New Jersey , was activated by ADC to provide logistical and contractual support for DEW Line operations. In 1958,

20196-491: The target. If the wavelength is much shorter than the target's size, the wave will bounce off in a way similar to the way light is reflected by a mirror . If the wavelength is much longer than the size of the target, the target may not be visible because of poor reflection. Low-frequency radar technology is dependent on resonances for detection, but not identification, of targets. This is described by Rayleigh scattering , an effect that creates Earth's blue sky and red sunsets. When

20349-585: The technology with the U.S. during the 1940 Tizard Mission . In April 1940, Popular Science showed an example of a radar unit using the Watson-Watt patent in an article on air defence. Also, in late 1941 Popular Mechanics had an article in which a U.S. scientist speculated about the British early warning system on the English east coast and came close to what it was and how it worked. Watson-Watt

20502-505: The thorough and time-consuming testing of each unit individually and of the system as an integrated whole. Finally all was ready, and on 15 April 1957 – just two years and eight months after the decision to build the Distant Early Warning Line was made – Western Electric turned over to the Air Force on schedule a complete, operating radar system across the top of North America, with its own communications network. Later,

20655-652: The time were known to be unsuited to the weather and atmospheric conditions to be encountered in the Arctic. Early efforts were aided when, by happenstance, the US Navy terminated its oil exploration activities in Alaska. The associated infrastructure that had been established in the arctic was quickly repurposed to serve early development of the DEW line. Material converted from Navy use included 1,200 tons of supplies, with many Caterpillar D8 tractors, heavy duty cranes, diesel generators, and radio equipment. Most fortunately,

20808-879: The transmitter. The reflected radar signals captured by the receiving antenna are usually very weak. They can be strengthened by electronic amplifiers . More sophisticated methods of signal processing are also used in order to recover useful radar signals. The weak absorption of radio waves by the medium through which they pass is what enables radar sets to detect objects at relatively long ranges—ranges at which other electromagnetic wavelengths, such as visible light , infrared light , and ultraviolet light , are too strongly attenuated. Weather phenomena, such as fog, clouds, rain, falling snow, and sleet, that block visible light are usually transparent to radio waves. Certain radio frequencies that are absorbed or scattered by water vapour, raindrops, or atmospheric gases (especially oxygen) are avoided when designing radars, except when their detection

20961-487: The two length scales are comparable, there may be resonances . Early radars used very long wavelengths that were larger than the targets and thus received a vague signal, whereas many modern systems use shorter wavelengths (a few centimetres or less) that can image objects as small as a loaf of bread. Short radio waves reflect from curves and corners in a way similar to glint from a rounded piece of glass. The most reflective targets for short wavelengths have 90° angles between

21114-472: The use of radar altimeters possible in certain cases. The radar signals that are reflected back towards the radar receiver are the desirable ones that make radar detection work. If the object is moving either toward or away from the transmitter, there will be a slight change in the frequency of the radio waves due to the Doppler effect . Radar receivers are usually, but not always, in the same location as

21267-419: The work would have to be completed in the long, dark, cold, Arctic winters, including over a month of polar night . From a standing start in December 1954, many thousands of skilled workers were recruited, transported to the polar regions, housed, fed, and supplied with tools, machines, and materials to construct physical facilities – buildings, roads, tanks, towers, antennas, airfields, and hangars – in some of

21420-608: Was a 1938 Bell Lab unit on some United Air Lines aircraft. Aircraft can land in fog at airports equipped with radar-assisted ground-controlled approach systems in which the plane's position is observed on precision approach radar screens by operators who thereby give radio landing instructions to the pilot, maintaining the aircraft on a defined approach path to the runway. Military fighter aircraft are usually fitted with air-to-air targeting radars, to detect and target enemy aircraft. In addition, larger specialized military aircraft carry powerful airborne radars to observe air traffic over

21573-464: Was chosen to be located in Streator, Illinois in 1952. The Streator DEW-Line Training Center became operational in 1956 and closed when operations were moved to Colorado Springs, Colorado in 1975. While few of the original designs for either buildings or equipment were retained, the trial installations did prove that the DEW Line was feasible, and they furnished a background of information that led to

21726-646: Was completed in 1990, and with the end of the Cold War and dissolution of the Soviet Union , the United States withdrew all of its personnel and relinquished full operation of the Canadian stations to Canada. Costs for the Canadian sector were still subsidized by the United States. However, the American flags were lowered at the Canadian stations and only the Canadian flag remained. The United States retained responsibility and all operational costs for North Warning System stations located in Alaska and Greenland. From

21879-660: Was excavated under the supervision of the Army Corps of Engineers for the construction of the NORAD Combat Operations Center beginning on May 18, 1961, by Utah Construction & Mining Company . The Space Defense Center and the Combat Operations Center achieved full operational capability on February 6, 1967. The total cost was $ 142.4 million. Its systems included a command-and-control system developed by Burroughs Corporation . The electronics and communications system centralized and automated

22032-402: Was judged to be less than desired and required. The staffed stations were retained to monitor potential Soviet air activities and to allow Canada to assert sovereignty in the Arctic. International law requires a country that claims territory to actively occupy and defend such territory. Because the advent of ICBMs created another attack scenario that the DEW Line could not defend against, in 1958

22185-471: Was later augmented, and modified/replaced by Project Stretchout and Project Bluegrass). The Guardian -class radar picket ships were based in Rhode Island and San Francisco , and covered picket stations 400–500 mi (640–800 km) off each coast. Barrier Force operations were discontinued by September 1965 and their EC-121K (WV-2 before 1962) aircraft placed in storage. Radar Radar

22338-425: Was nicknamed " The Notch " (or formally as the 8th AF "Post-Attack Command and Control System Facility, Hadley") and was hardened to protect it from the effects of a nearby nuclear blast and designed so that the senior military staff could facilitate further military operations. Four years later, construction at Cheyenne Mountain was started to create a similar protection for the NORAD command post. Cheyenne Mountain

22491-538: Was proposed as an inexpensive solution using bistatic radar . This provided a "trip wire" warning located roughly at the 55th parallel , giving commanders ample warning time, but little information on the targets or their exact location. The MCL proved largely useless in practice, as the radar return of flocks of birds overwhelmed signals from aircraft. The DEW Line was proposed as a solution to both of these problems, using conventional radar systems that could both detect and characterise an attack, while being located far to

22644-500: Was re-designated as the J36 branch within the NORAD and USNORTHCOM's Operations Directorates. Since 2002, the complex has been classed as Cheyenne Mountain Air Force Station and has been used in crew qualification training, while the former command function has been redesignated as the "NORAD and USNORTHCOM Alternate Command Center" since 2008 after all the original functions of the complex were removed to Peterson Air Force Base. The complex

22797-748: Was sent to the U.S. in 1941 to advise on air defense after Japan's attack on Pearl Harbor . Alfred Lee Loomis organized the secret MIT Radiation Laboratory at Massachusetts Institute of Technology , Cambridge, Massachusetts which developed microwave radar technology in the years 1941–45. Later, in 1943, Page greatly improved radar with the monopulse technique that was used for many years in most radar applications. The war precipitated research to find better resolution, more portability, and more features for radar, including small, lightweight sets to equip night fighters ( aircraft interception radar ) and maritime patrol aircraft ( air-to-surface-vessel radar ), and complementary navigation systems like Oboe used by

22950-603: Was subject to delays and cost overruns. By 1992, the project was estimated to be delayed to 1995 and cost projected to increase from $ 142 million to $ 234 million. By 1992, the U.S. Space Command Space Surveillance Center (SSC) was the data analysis and tracking center for Baker-Nunn camera images and Cheyenne Mountain was connected to the AN/URC-117 Ground Wave Emergency Network (GWEN) communication site in Pueblo, Colorado . By 1995,

23103-463: Was the first to use radio waves to detect "the presence of distant metallic objects". In 1904, he demonstrated the feasibility of detecting a ship in dense fog, but not its distance from the transmitter. He obtained a patent for his detection device in April 1904 and later a patent for a related amendment for estimating the distance to the ship. He also obtained a British patent on 23 September 1904 for

23256-446: Was the longest off-road vehicle ever built at the time, with its six cars (including the locomotive) measuring a total of 274 ft (84 m). Each car was driven by four 7.3 ft (2.2 m) tall wheels and tires. The 24-wheel-drive was powered by two 400 horsepower Cummins diesel engines connected to a hub motor. It had a payload capacity of 150 short tons (140 t; 130 long tons), and could traverse nearly any terrain. It had

23409-489: Was upgraded to the more robust UNIVAC 1100/42 . The 427M system, intended to modernize systems and improve performance, was initially "wholly ineffective" and resulted in several failures of the Worldwide Military Command and Control System (WWMCCS) system. In 1979 and 1980, there were a few instances when false missile warnings were generated by the Cheyenne Mountain complex systems. For instance,

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