science

North Atlantic Radio System

North Atlantic Radio System is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand North Atlantic Radio System rather than just read about it. In short: The North Atlantic Radio System (NARS) was a chain of 5 tropospheric scatter communication sites. It was an expansion of the former Distant Early Warning Line (DEW Line).

Key takeaways

North Atlantic Radio System belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect North Atlantic Radio System to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of North Atlantic Radio System from memory before moving on to harder problems.

Reference excerpt

The North Atlantic Radio System (NARS) was a chain of 5 tropospheric scatter communication sites. It was an expansion of the former Distant Early Warning Line (DEW Line). NARS was built for the United States Air Force (USAF) by Western Electric (AT&T) and its sites were maintained under contract by ITT Federal Electric Corporation (now ITT Federal Services Corp.). All NARS stations were supervised and controlled by the USAF, by agreement with the Canadian and Danish governments.

Previous systems Source: In the early 1950s, arctic surroundings and weather conditions of northern Canada made construction and manning of HF and VHF radio or microwave relay stations almost impossible. However, there was an urgent need for reliable data and communication facilities from the radar stations in the north to their control centers in the south. The initial phase used tropospheric scatter radio communication. Powerful radio signals in the kilowatt range were scattered off the troposphere onwards to distant receiving stations. The receiving stations used gigantic billboard-like antennas, picking up just a fraction of the transmitted signal, meaning that the antenna and equipment maintenance and alignment had to be executed very carefully. Construction of this system, code-named Pole Vault, started in 1954, became operational in 1955, and was extended in 1956. This troposcatter system had been supported by an undersea data cable system stretching from Thule airbase in Greenland via Cape Dyer to Newfoundland, Canada. The undersea cable system was unreliable, however, being cut many times by trawlers and icebergs. A better data transfer system was needed. In 1962, the new SAGE system led to a gradual shutdown of the Pole Vault system. SAGE consisted of large computers and associated networking equipment that coordinated data from many radar sites and processed it to produce a single unified image of the airspace over a wide area. SAGE directed and controlled the NORAD response to a Soviet air attack, operating in this role from the late 1950s into the 1980s. Construction of the large Ballistic Missile Early Warning System (BMEWS) radars at Thule, Greenland, Fylingdales, England, and another radar chain through Greenland, Iceland and the Faroe Islands, called for new powerful troposcatter communication stations linking all these radar sites to the NORAD headquarters in Colorado. This communication chain became known as the North Atlantic Radio System (NARS).

Equipment and configuration Source: The NARS used AN/FRC-39(V) and AN/FRC-56(V) transmitting and receiving equipment, manufactured by Radio Engineering Laboratories, which could be configured for 1 kW, 10 kW or 50 kW power output depending on the range and/or quality of signal required. NARS sites were configured for 10 kW output, with the exception of site 41 in both directions and site 42's connection to site 41, which used 50 kW. Each set consisted of 2 transmitters and 4 receivers, for redundancy, and to boost signal to noise ratios. The vacuum tube technology proved time-consuming to maintain at high levels of efficiency. The 50kW shots used 120 ft antennas and the 10kW shots used 60 ft antennas. The equipment was configured for quad diversity, using polarity diversity, space diversity, frequency diversity, and combiner diversity. This was typical for most troposcatter communications over difficult paths. Levels of service proved extremely variable with the effects of weather and finicky equipment frequently causing loss of connection. Improvements were gained through better maintenance procedures but did not change significantly until the introduction of solid state technology. The system was able to transmit at 9.6 kbit/s, a very fast data connection at the time, by the time of closure.

Closure The system was closed down in 1992 after 30 years of service. With the advent of satellite communications the days of the troposcatter networks were over, but NARS was closed down early due to the loss of the DYE-2 DEW Line station in 1988, severing the network's connection with the rest of the DEW line. Site 46 also had to close to make way for the new BMEWS Phased Array Radar at RAF Fylingdales.

NARS sites

From 1960, five troposcatter sites were built.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with North Atlantic Radio System

Start with the simplest possible case. Write down what North Atlantic Radio System claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to North Atlantic Radio System before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about North Atlantic Radio System ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of North Atlantic Radio System

In research: North Atlantic Radio System appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses North Atlantic Radio System in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: North Atlantic Radio System is common in secondary-school and first-year university syllabi. It links to neighbouring topics Military radio systems, Radio frequency propagation, Telecommunications equipment of the Cold War, so understanding it makes those chapters shorter.
In everyday life: Look for North Atlantic Radio System outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study North Atlantic Radio System in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what North Atlantic Radio System means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain North Atlantic Radio System out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is North Atlantic Radio System in simple terms?

The North Atlantic Radio System (NARS) was a chain of 5 tropospheric scatter communication sites. It was an expansion of the former Distant Early Warning Line (DEW Line).

Why does North Atlantic Radio System matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study North Atlantic Radio System?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on North Atlantic Radio System.