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The Differential Absorption LIDAR (DIAL) system is a lidar instrument
that sends pulses of laser radiation at different wavelengths into the
atmosphere to measure ozone and also simultaneously measure aerosols
and clouds. The laser beams are pointed both upwards and downwards out
of the aircraft. The UV DIAL system uses five laser (or lidar)
wavelengths in three different regions of the electromagnetic spectrum
(Fig. 1): two in the UV region for ozone measurements, two in the
visible region, and one in the near infrared (IR) region. IR and
visible wavelengths both measure aerosols and clouds. Comparing these
two wavelengths can reveal information about the size distribution of
aerosols. The two UV wavelengths determine the profile of ozone by
analyzing the absorption differences due to ozone between the two
lidar returns. From this measurement, scientists can determine the
location and amount of aerosols, clouds, and ozone along the
line-of-sight of the UV DIAL system.
Additional information available at
"http://asd-www.larc.nasa.gov/lidar/lidar.html"
[Summary provided by NASA}
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