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NIST LIDAR DISTANCE MEASUREMENT VIDEO -- Transcript for the Visually Impaired (back to video)
VISUAL: Fade up from black to image of a ruler. Image of a Global Positioning System device is superimposed atop the ruler.
Narrator: From the ruler . to the Global Positioning System .
VISUAL: Video of automobile traffic moving at faster-than-normal speed along a highway.
Narrator: Humans are constantly searching for better and better ways to measure distance.
VISUAL: NIST laboratory showing close-up view of monitors displaying rapidly changing digital numbers. Cut to view of NIST researcher working on bench filled with optics equipment.
Narrator: Now . a new method of measurement from the National Institute of Standards and Technology . or NIST... may turn out to be one of the most precise ever.
Narrator: The super-accurate NIST system can pinpoint the distance to multiple objects .
Narrator: . hundreds of kilometers apart . and define that distance down to a nanometer . or a billionth of a meter.
VISUAL: Image of pins as camera zooms in on one pinhead.
Narrator: That's one million times smaller than the head of a pin.
Text on screen: LIDAR, Light Detection and Ranging
Narrator: To make this happen . NIST employs a technique called LIDAR . which stands for Light Detection and Ranging.
Text on screen: Nate Newbury, NIST Physicist
Nate Newbury: "It's basically the laser equivalent of radar, which is the radio equivalent of sonar, which is what bats used to locate things by sending out a sound wave. So, with laser radar or LIDAR, it's the same idea. You send out light, and you look at what comes back to get some information."
Narrator: To achieve its amazing nanometer precision, the NIST measurement system enhances the power of LIDAR with the help of a device called a frequency comb.
VISUAL: Close up of lens used to focus laser followed by researcher's hand connecting a cable to back of the optics device.
Narrator: What the comb does is give off ultrashort pulses of laser light every ten billionths of a second.
VISUAL: Close-up of laser light flashing through the lens.
Narrator: Remarkably . these pulses are emitted at very precise times . with each burst a duplicate of the previous one.
VISUAL: Image of light affected by frequency comb that appears as a circle of different colored bars from red to violet (the colors being the rainbow of the visible light spectrum).
Narrator: The frequency comb gets its name because a series of its pulses appear as a spectrum of evenly spaced colors that resemble the teeth of a comb.
Narrator: It's the precise timing and control of the pulses that make it possible to perform super-accurate measurements.
VISUAL: Nate Newbury
Newbury: "Basically, we can take tem and bounce them off an object because we know exactly what the pulse looked like when it went out and we can measure it when it comes back . and we can measure exactly how long it's been delayed in that time of flight and then from that, we can measure the range to an object."
Narrator: So what jobs may await the NIST LIDAR measurement system?
VISUAL: Video of automobile being built in factory by robots.
Narrator: One possibility is helping ensure the precise fit of manufactured parts for cars and planes .
VISUAL: Animation of moving past planets in space.
Narrator: Another potential use of the LIDAR system is literally out of this world .
VISUAL: Nate Newbury
Newbury: "In the other application that we are excited about would be using these to support the next generation of satellite-based instruments .
VISUAL: Animation of satellite orbiting the Earth.
Newbury: ". where the instrument is distributed among different satellites and you need them all to be in correct orientation and pointing in respect to each other."
VISUAL: Animation of space probe with camera "eye" heading toward a planet.
Narrator: Being able to precisely fly a host of satellites in formation may one day lead to networks of space-based telescopes .long-range eyes capable of seeing black holes or Earth-like planets in other solar systems.
VISUAL: Nate Newbury
Newbury: "Those are very complex instruments, and they require a lot of technology, and this would, we hope, maybe be one piece that could eventually feed into that to support that sort of effort ."
Produced by National Institute of Standards and Technology Public Affairs Office, June 2009
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