Dr. John Kim, who oversees navigation and timekeeping technology programs at ONR, points out that while commercial atomic clocks already are available, they’re relatively large and bulky. A typical Cesium beam atomic clock measures about 4,800 cubic centimeters in volume (about the size of a large backpack) and consumes up to 50 watts of power.
Kernco, Inc., of Danvers, MA, is a longtime builder of precision timing devices. In October, Kernco will deliver a field-tested unit of the Ultra-miniature Rb Atomic Clock to ONR that, Kim points out, is about half the size of the current commercially available ones but improves on power needs by a factor of four. The tiny size of the Kernco clock, he says, will permit new degrees of design flexibility for systems, especially aircraft, which place a high premium on size and weight.
ONR awarded Kernco a contract in Nov. 2000 for development of the 40 cc clock. The Kernco laser-based Ultra-miniature Rubidium Atomic Clock, entirely optical in nature, is a key breakthrough for miniaturizing atomic clocks. The laser light source is derived from a revolutionary technology breakthrough called Vertical Cavity Surface Emitting Laser (VCSEL), developed to meet the needs of fiber-optic communications industry for extremely compact lasers.
The differences between this new clock and other atomic clocks are the size, the weight, the power consumption, the transportability, and the price. The Kernco clock is a tactical grade atomic clock.
Kernco has already begun work for ONR on a yet smaller 10 cc Rubidium Atomic Clock, but even that will not be the last word: Other agencies are researching the development of the still-more accurate atomic clock.
How much more accurate of a timing device do we need?
For an object (ie. missle) travelling at the speed of sound (340.29 m/s), using this device for positioning would have an accuracy of +/- 1.08 nanometers, heck even at mach 5 it is only +/- 5.4 nanometers, is this not accurate enough?
Even if something travelling at c (299 792 458 m/s), the margin of error is +/- 0.95 millimeters, which would be irrelevant as the clock travelling at c would stop and it would exist only in a state of energy.
Atomic clocks are at the heart of Global Positioning System (GPS) technology. Really accurate ones like these could enable precision location down to the inch / centimeter level instead of the 30 meters now in effect. Once you get to that level, lots of things open up, especially in the area real-time atonomous vehicle control.
The GPS site still mentions 100 meters, civilian ones are orders of magnitude behind what the military has (civilian C/A code vs. military P code). I read an article a while back about some college (MIT?) students who used triangulation between the strength in the signals of the GPS system to archive this kind of accuracy or something along that line as I recall.
The “random” error (Select Avaliability – S/A) that the military was introducing into the GPS signal (C/A) was turned off in May of 2000, and if you are willing to spend the money, you can get a unit with < 3m accuracy 99% of the time, and if you REALLY have money to spend ($40K+) you can get survey rated GPS that are good to the sub-centimeter level
They (the US government) have this already, they just don’t want you to have it.
The ESA Galileo System will be accurate down to the meter when it goes into operation in 2010.
You are correct there are all kinds of resolutions you can get with the current GPS system. AS I understand it, you can get 10-30 meters anywhere in the world with the military P code, which is good enough for cruise missiles, and this is the best you can get without triangulation and prior-ground surveys, which are required to get to the sub-meter and sub-centimeter levels. While this is great for airports to equip auto-landing of ordinary commercial jets (which has been demonstrated) what you really want is sub-meter to centimeter resoultion EVERYWHERE without prior surveys and super expensive equipment. As I understand it, for THIS you need cheap and more precise atomic clocks IN THE GPS, not the orbital satellites.
But I’m the first to admit I’m not an expert in this area…just a very interested admirer of the technology.