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Tiny atomic clock could make smarter missiles - Unlike GPS Satelites they cannot be Jammed
NewScientist ^ | 09/03/03 | Will Knight

Posted on 09/05/2003 10:35:28 AM PDT by bedolido

A matchbox sized atomic clock could be used to build more accurate automated aircraft navigation systems, its US military creators say.

Scientists at the Office of Naval Research have developed a functioning atomic clock measuring 40 cubic centimetres in volume - about the size of a matchbox.

The Ultra-miniature Rubidium Atomic Clock is so precise that it will lose only one second over 10,000 years. It also uses just one watt of power. Existing atomic clocks are many orders of magnitude larger - typically around 4,800 cubic centimetres - and normally consume around 50 watts.

John Kim, who led the research, says the device is small enough to be built into missiles or unmanned aircraft. It could then be used by an on-board computer to calculate position very accurately based on velocity and time.

Some modern missiles rely on Global Positioning System (GPS) satellites to calculate their position and home in on a target. But this system may be susceptible to jamming. Another means of on-board navigation is a gyroscope and accelerometer, but this technique is much less accurate.

Surrounding electrons

Kim says accuracy of the clock used can make a big difference to navigational precision. "If the clock is very accurate, the uncertainty is very small," he told New Scientist. "If it is less accurate it could be 30 feet instead of three feet."

Atomic clocks provide precise time measurements by measuring the oscillation of the nuclei of an atom and its cloud of surrounding electrons. This remains very stable over space and time. Rubidium-based atomic clocks are less accurate than caesium or hydrogen ones, but can more easily be miniaturised.

Kim says other research groups are working on similarly small atomic clock designs but believes theirs to be the most compact and power-efficient atomic clock anywhere. Kim says the clock would also be relatively cheap to make, costing around $2,000 per unit.

Atomic clocks are already extremely important to global navigation. Larger ones are installed aboard GPS satellites and provide highly accurate timestamps for each signal. This enables a ground-based receiver to work out how far away each satellite is and calculate its own coordinates. Atomic clocks are also used on the ground to synchronise computer networking equipment.

Will Knight


TOPICS: Culture/Society; Extended News; Miscellaneous; News/Current Events; Philosophy
KEYWORDS: atomic; atomicclock; clock; gps; jammers; miltech; missiles

1 posted on 09/05/2003 10:35:29 AM PDT by bedolido
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To: bedolido
Of course, if you just make like Q and change the gravitational constant of the Universe, you can throw the clock off :o)
2 posted on 09/05/2003 10:36:39 AM PDT by Poohbah (Crush your enemies, see them driven before you, and hear the lamentations of their women.)
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To: Poohbah
Yes, but then Wesley can reconfigure the quantum tachyon hyperbabbelator plasma frizzeltron emitter array to compensate for it. Sheesh don't you know anything? ;-)
3 posted on 09/05/2003 10:43:00 AM PDT by egarvue (Martin Sheen is not my president...)
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To: bedolido
I think clock accuracy has not been an issue in missile guidance.
4 posted on 09/05/2003 10:44:39 AM PDT by jlogajan
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To: jlogajan
Indeed! If you know time and velocity, you can infer position. You might know time to 11 decimal places - or maybe more. To how many decimal places can you know velocity? 5 maybe, or 6 at best?
5 posted on 09/05/2003 10:46:58 AM PDT by coloradan
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To: egarvue
I still have my original Mickey Mouse watch in semi-pristeen (sp) condition from 1956. I have to whined winde wind it though.
6 posted on 09/05/2003 10:49:20 AM PDT by bedolido (A Riddle inside a Conundrum within a Parable surrounded by an Enigma)
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To: bedolido
Just think how many things Clinton could sell/give away if she's elected.
7 posted on 09/05/2003 10:52:35 AM PDT by Taiwan Bocks
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To: bedolido
I have a watch that is accurate to 10,000,000 decimal places... twice a day
8 posted on 09/05/2003 10:53:38 AM PDT by laker_dad
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To: coloradan
Especially when you consider that velocity has to be calculated by integrating acceleration from strain-gage based accelerometers. There are cumulative integration errors that increase error the longer you fly without a 'fix' from a landmark, GPS, Loran or whatever.
9 posted on 09/05/2003 11:38:56 AM PDT by MalcolmS (Service Guarantees Citizenship. Citizenship guarantees opportunity. After that, it's up to you!)
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To: bedolido
Listen up Timex! The sun varies but this clock doesn't!
10 posted on 09/05/2003 11:50:12 AM PDT by azhenfud ("He who is always looking up seldom finds others' lost change...")
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To: Thud
Something beyond GPS for you to consider.
11 posted on 09/05/2003 12:37:27 PM PDT by Dark Wing
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To: egarvue
One thing I like about the show "Stargate SG-1" is that it has a built in techno-babble clamp in the persona of "Jack", who butts in whenever some character starts techno-babbling and says something like "Whoa, stop. Will it work?"

Just can't STAND that "Starfleet" stuff any more. Way too PC for me.
12 posted on 09/05/2003 12:54:21 PM PDT by Elliott Jackalope (Once it was "Warp factor seven", now it's "Set the Ring to the new coordinates". Life moves on...)
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To: Elliott Gigantalope
LOL. I am a very bitter ex-Trek fan; the preachy political correctness and the technobabble that substituted for a plot finally turned me off. I've never had a chance to see SG-1, but many of my friends who watch it say its very good. I'll have to track it down and give it a go.
13 posted on 09/05/2003 1:42:13 PM PDT by egarvue (Martin Sheen is not my president...)
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