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Instrument: WINDII : Wind Imaging Interferometer
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Associated Platforms
UARS

Related Data Sets
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Description
The Wind Imaging Interferometer (WINDII) on UARS determined
temperature and winds in the mesosphere and the lower thermosphere by
measuring both Doppler widths and shifts of isolated spectral lines
emitted by airglow and aurora. The principal objectives were (1)
measure 2-dimensional vertical profiles of horizontal wind velocity
and Doppler temperature of the neutral atmosphere from 70 to 310 km as
a function of latitude and time, (2) measure the global distribution
of small-scale wave-like structures on a 3 km scale, and (3) studied
the dynamic and thermal aspects of the neutral atmospheric energy
balance. The WINDII instrument viewed the atmospheric limb
simultaneously in two directions, 45 degrees and 135 degrees from the
velocity vector. An imaging detector provided simultaneous
measurements of temperature and wind profiles over the instrument's
entire altitude range (70 to 310 km) with a vertical resolution of 2
km and horizontal resolution of 20 to 100 km. Emission lines of OI,
OH, O+ and O2 were measured to cover both daytime and nighttime over
the altitude range and provide thermospheric ion wind velocities. The
instrument was basically a CCD camera which viewed the Earth's limb
through a field-widened Michelson interferometer. The instrument took
4 images with the interferometer optical path difference changed by
1/4 wavelength between images. From these images, the fringe phase
(leading to wind velocity), fringe modulation (leading to
temperature), and emission rate was determined. The Michelson optics
consisted of a cemented glass hexagonal beamsplitter, a glass block
with a deposited mirror and a glass block combined with an air gap and
a piezoelectrically driven mirror. The CCD camera consisted of a fast
camera lens and a 320 x 256 pixel detector array cooled to -50 C.
Interference filters were mounted in a temperature-controlled filter
wheel assembly to isolate specific spectral lines.

See
Reber, Carl A.,"The Upper Atmosphere Research Satellite",Trans., Am. Geophys.
Union EOS, Vol. 71, No. 51, pp. 1867-1868,1873-1874,1878, December 18,
1990.

Online Resources
http://disc.sci.gsfc.nasa.gov/guides/GSFC/guide/UARS_platform.gd.shtml
http://www.windii.yorku.ca/