WEBVTT FILE

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[SFX]

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Hey John, I'm finished with your model.

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Thanks

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So you looking forward to the launch?

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You have no idea.

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[music and sounds of children]

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My project is a LiDAR instrument called CATS.

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And it measure clouds and pollution in the Earth's atmosphere.

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These are important because they affect society in many ways.

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So Little Johnny, how does this LiDAR work?

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LiDAR is actually quite simple.

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You shine laser light at the Earth's atmosphere and measure the amount of light
scattered back.

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My instrument... [voice fades out]

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Today, a team at NASA Goddard is preparing to demonstrate,

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for the fist time in space, a 3-wavelength, laser remote sensing instrument.

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The Cloud-Aerosol Transport System, or CATS, will measure clouds and aerosols
in the Earth's atmosphere.

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To obtain this data, CATS uses a laser that generates 3 wavelengths or
"colors," of light.

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Internal to the laser, special optical crystals are used to generate these
wavelengths

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by adding the energy of two photons, to make a single new photon.

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The final output beam is made up of all three wavelengths

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and these photons are transmitted in groups, towards the atmosphere, at the
speed of light.

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As photons encounter clouds or particles, scattering of the laser beam occurs.

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Very few of the photons scatter directly back to the optical telescope,

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but the ones that return, are collected and counted by sensitive detectors and
electronics.

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By timing the difference between emission and detection, the precise altitude
of the particles can be determined.

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While monitoring global hazards from above,

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CATS will determine the height, thickness and the extent of smoke, dust
particles,

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and volcanic ash in our atmosphere.

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Improving cloud data will allow scientist to create more accurate climate
models,

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which in turn, will improve air quality forecast and health risk alerts.

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This cost-effective, technology demonstration will utilize

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the International Space Station as a scientific platform for up to 3 years.

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Once proven, the CATS technology can be used to further a larger, free-flier
satellite mission.

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Until then, CATS will provide information that can help us better understand

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Earth's complex atmospheric processes.

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[Music/SFX]

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[SFX]

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