Nation's Master Clock Used to Trigger Colors

Story Number: NNS090710-23Release Date: 7/10/2009 4:55:00 PM
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By Darren Harrison, Naval District Washington Public Affairs

WASHINGTON (NNS) -- The most accurate sounding of colors in the world, down to one one-billionth of a second, was sounded for the first time at Naval Support Facility (NSF) Naval Observatory July 2.

The key to the accuracy of the sounding of morning and evening colors is that the procedure is tied to the nation's Master Clock.

"The Naval Observatory is home to the Master Clock, which is an atomic clock that measures time to the nanosecond," said Naval Support Activity (NSA) North Potomac Commanding Officer Cmdr. Scott Merritt. "The procession of colors is tied to the clock as a direct input, a direct feed from the atomic clock that feeds into our giant voice system. At 7:55:00.00.00, all the way out to as many decimal points you want to count, the giant voice system will sound first call to colors and five minutes later the call to attention followed immediately by the national anthem."

The sounding of morning and evening colors was established by the British Royal Navy and later adopted by the United States Navy. The practice was first codified in 1843 at which point morning colors was based on the time of sunset. If the sun set before 6 p.m. morning colors were sounded at 8 a.m. and if it set after 6 p.m. then colors were sounded at 9 a.m. The present practice of always making morning colors at 8 a.m. was set by regulation in 1870.

The Naval Observatory at its present location goes back to 1893 and even at that time its mission was the determination of precise time. However, morning and evening colors was never part of the regimen at the Naval Observatory.

"It's one of those things that when growing up through the Navy and being in Navy installations all over the world, and hearing colors being played it was one of those things, well why don't we do it here?" said Merritt. "So, when you arrive at a place you start to make a list of things you want to accomplish and this was on my list.

"What started the push ironically enough is my Emergency Management Officer [Doug Benson] sent me an e-mail, about a year ago, and said 'we need to test our emergency broadcast system, when do you want to do it?' And my response was to him, I want to do it every day, twice a day in the conduct of morning and evening colors," Merritt said. "At first he didn't think I was serious but he quickly realized that this was an initiative that we were going to take on."

Unlike the other services which hold their evening services at 5 p.m. every day, the Navy executes evening colors at sunset. The Naval Observatory, in addition to being home to the Master Clock, produces the Nautical Almanac which is used by Sailors around the world to determine the rise and fall of celestial objects, including the sun.

"Fortunately for us, the Nautical Almanac is one of the products produced here at the Observatory," said Merritt. "So, with a little help from a contractor and some pretty creative computer programming we were able to take the data from the Nautical Almanac as another input to the evening colors event so that at five minutes to the exact time of sunset, first call will sound and right at sunset evening colors will sound."

Benson explained the process required coordination between the staff and trial and error to get the computer program to synchronize with the time services clock.

"There were a lot of challenges to overcome," Benson said. "Basically it was discovering that the system would not work on its own, that it required the integration of the clock. And once it was decided that we were going to go that way we had to get with time services and coordinate a time when we could talk about how to do this. Then, with the cooperation of a contractor, we were able to develop a computer program."

Following the inaugural sounding of colors ceremony at the Naval Observatory, Merritt said the event was "perfect."

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