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CHIPS Articles: Broadcasting from the beach: NIST Hawaii

Broadcasting from the beach: NIST Hawaii
Coordinated Universal Time signals for the Pacific region
By CHIPS Magazine - August 28, 2018
The National Institute of Standards and Technology (NIST) has campuses in Maryland, Colorado, South Carolina and Hawaii?

Yep, tucked within the U.S. Navy’s Pacific Missile Range Facility on the western Hawaiian island of Kauai, sits one of NIST’s shortwave radio stations, perhaps best known by its call sign, WWVH.

WWVH’s chief objective is to broadcast Coordinated Universal Time (UTC) — the official time for the world — throughout the Pacific region. These signals help residents, from Alaska to Australia and from California to China, coordinate, calibrate and synchronize their clocks, networks and equipment, which are vital to telecommunications, internet connections and a wide array of government and consumer services, according to a NIST blog.

In addition to accurate time and frequency information, WWVH also broadcasts weather alerts and space weather reports.

WWVH broadcasts in several frequencies: 2.5, 5, 10 and 15 megahertz. The different frequencies cast a broad net so that users of the broadcast will receive a signal regardless of interference from mountains, atmospheric activity or time of day. The system allows users to always have access to the correct time as well as the other information provided by WWVH, NIST said.

WWVH’s sister station, WWV, broadcasts from Fort Collins, Colorado. Both stations broadcast on the same frequencies, and if the ionospheric conditions are exactly right, users can hear both stations. In addition to using different broadcast voices, WWVH and WWV make their announcements at different time intervals to prevent overlap and confusion among listeners.

What time is it?

UTC(NIST) is the coordinated universal time scale. The UTC(NIST) time scale encompasses a collection of cesium beam and hydrogen maser atomic clocks, which are regularly calibrated by the NIST primary frequency standard. The number of clocks in the time scale varies, but is typically around 10. The outputs of the clocks are combined into a single signal by using a weighted average. The most stable clocks are assigned the most weight. The clocks in the UTC(NIST) time scale also contribute to the International Atomic Time (TAI, from the French name temps atomique international) and Coordinated Universal Time.

UTC(NIST) serves as a national standard for frequency, time interval, and time-of-day. It is distributed through the NIST time and frequency services and continuously compared to the time and frequency standards located around the world.

USNO time versus NIST time

The U.S. Naval Observatory (USNO) maintains the U. S. Department of Defense reference for time and time interval. USNO has an ensemble of atomic clocks, which is used to derive a time scale called UTC(USNO). The clocks in the collection contribute to International Atomic Time and Coordinated Universal Time. UTC(USNO) and UTC(NIST) are kept in very close agreement, typically to within 20 nanoseconds, and both can be considered official sources for time in the United States. Recent differences between the two time scales are published in the NIST Time Scale Data Archive.

“This Side of Paradise”

In 1947, NIST determined it needed to create a second station to supplement WWV and expand its coverage area to the Pacific Rim. The WWVH broadcast station was originally built at Kihei on the Hawaiian island of Maui in 1948. After 20 years, however, the encroaching ocean began damaging property and equipment, NIST said. So in 1971, WWVH moved nearly 322 km (200 miles) west to its current home on Kauai. The more-westerly location proved ideal because it allowed the station’s signal to reach to even more distant locations, NIST said.

The ocean setting is a dream for relaxation and water sports, but can wreak havoc on the broadcast station. The salty air and heat have literally caused the transmitters to catch fire, according to NIST. In one instance, the naval base’s fire department was alerted before the radio station staff was. Unfortunately, the firefighters put out the fire with a dry chemical agent, a corrosive material that rendered the transmitter useless. Shortly after replacing that transmitter, its backup failed.

Time marches on, however.

Despite weather conditions and technical challenges, staff maintain a 98 percent on-air rate, which is amazingly good, according to John Lowe, leader of the Time and Frequency Services Group at NIST’s Boulder, Colorado, campus. Lowe manages WWVH and WWV, in addition to the long-wave station WWVB, which is also located at Fort Collins.

Lowe visits the station at least once every two years. To keep staff up to speed on operations for both stations, there is an annual rotation of staff members between WWV and WWVH.

Someone is always on call at the WWVH broadcast station, and it’s all-hands-on-deck during inclement weather, such as the April 14-15, 2018, mega storm that hammered the northern part of the island with 127 cm (50 inches) of rain in 24 hours, but which thankfully had no effect in the area around WWVH, NIST said.

At one point, there were nine employees at WWVH, including an on-site groundskeeper for the station’s 30 acres. Back then, the station was manned 24/7, but automation has helped reduce the staff down to four, who are now responsible for all station and land maintenance, according to NIST. Nonetheless, inspections are conducted daily to ensure the broadcasts are in close agreement with the UTC.

For the staff, the work is both fascinating and exciting. But what about working so close to an idyllic beach? Do staff members surf and soak up the sun during lunch?

In fact, most of the staff stay in the air-conditioned building during lunch, said engineer Dean Okayama.

“It’s like asking someone who lives next to Disneyland if they go every day,” he said. “We don’t eat outside and lay under the palm trees. It’s hot and humid. There are bugs flying around.”

Still, outside of work, the pace of life on Kauai is generally more relaxed than the mainland or even the larger islands of Hawaii. And although the working conditions sound idyllic, many of those who move to Hawaii develop “rock fever,” the claustrophobic feeling that comes from being on a small island, NIST said.

Passion for the mission

The staff is fiercely dedicated to their work, NIST said. On March 7, 2018, the new NIST director Walter Copan and his wife, who were on a long-planned Hawaiian vacation, took the opportunity to stop by the site.

It was the first time that a NIST director had ever visited the island.

“The WWVH team are truly NISTers, and they are our ambassadors of metrology on America’s westernmost shores,” Copan said. “The WWVH team was also recognized by a 2008 NIST Bronze Medal, now on display in their entrance hallway, for the development and installation of a new antenna array by the employees themselves. Their work is a true example of the NIST values, which include perseverance and inclusivity.”

The WWVH station recently survived another epic storm. Last week Rear Adm. Brian Fort, commander, Naval Surface Group Middle Pacific, issued guidance in preparation for Hurricane Lane’s approach, according to the command's website. U.S. Navy ships and submarines based in Hawaii not currently undergoing maintenance availabilities had begun to sortie as the storm advanced toward the Hawaiian Islands, Fort said. The Navy orders a sortie during potentially extreme weather conditions to reduce the risk of significant damage to ships and piers during high winds and seas.

Hurricane Lane was a 130 mph wind speed, Category 4 storm when it hammered Hawaii’s Big Island with three feet of rain Aug. 23, but by Aug. 25, “the dangerous hurricane has been downgraded to a tropical storm with 65 mph winds,” the Defense Department said in a release. Happily, the U.S. Navy reported there was no damage to ships or to naval installations by the hurricane. The Navy’s Pacific Missile Range Facility on the island of Kauai was unharmed by Hurricane Lane, the Navy reported.

Sadly, not all areas of Hawaii fared as well. Lane dropped 52.02 inches of rain on Hawaii from August 22-26, the second highest rainfall total from a tropical cyclone in the U.S. since 1950, according to preliminary data from the National Weather Service. Hawaii is still reeling from the storm as residents clean-up from days of heavy rainfall and remain on alert for more rain, flash floods and landslides.

We wish our Hawaiian friends well as they recover from the storm.

Beach in Lihue, Kauai, Hawaii. Photo by Ron Cogswell/CC BY-NC 2.0
The radio station entrance sign. Photo by D. Okayama
A typical antenna at the station, constructed of fiberglass (to resist corrosion from the salty ocean air) with a copper-wound core. Seen in the distance is the island of Niihau. Photo by D. Okayama/NIST
The former incarnation of WWVH when it was located on Maui from 1948 to 1971. Notice how close it was to the shore—way too close, as it turned out. NIST Archives
WWVH’s time and frequency rack: digital recorders; multichannel chart recorder; clocks A, B and C (at least two of which must agree before broadcasting their time); and an error-detection/auto-switching system. Photo by D. Okayama/NIST
The WWVH facility and the solar array built in 2010 to help supply the station with electricity. Photo by D. Okayama/NIST
From left to right: Dean Takamatsu, Dean Okayama, Director Copan, Adela Mae Ochinang and Chris Fujita. Photo by D. Okayama/NIST
PACIFIC OCEAN (Aug. 23, 2018) A satellite image of Hurricane Lane at 10:45 p.m. Hawaii Standard Time. At 11 p.m. Hawaii Standard Time, the category 4 hurricane, which was located about 350 miles south of Honolulu, Hawaii, was moving northwest at 7 mph with maximum sustained winds of 145 mph. U.S. Navy photo/Released
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