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Instrument Description
In order to demonstrate the capabilities of polarimetry an instrument
that can make either ground-based, or aircraft measurements, the
Research Scanning Polarimeter (RSP) has been developed by SpecTIR
Corporation. This instrument has similar functional capabilities to
the proposed EOSP satellite instrument. Currently data acquisition is
performed on a laptop, which is shown here and gives an indication of
the size of the instrument. The scientific requirements for the
polarimetric measurements are satisfied by the RSP through its high
measurement accuracy, the wide range of viewing angles measured and by
sampling of the spectrum of reflected solar radiation over most of the
radiatively significant range. The RSP instrument uses a polarization
compensated scan mirror assembly to scan the fields of view of six
boresighted, refractive telescopes through +/-600 from the normal with
respect to the instrument baseplate. The refractive telescopes are
paired, with each pair making measurements in three spectral
bands. One telescope in each pair makes simultaneous measurements of
the linear polarization components of the intensity in orthogonal
planes at 00 and 900 to the meridional plane of the instrument, while
the other telescope simultaneously measures equivalent intensities in
orthogonal planes at 450 and 1350. This approach ensures that the
polarization signal is not contaminated by uncorrelated spatial or
temporal scene intensity variations during the course of the
polarization measurements, which could create false
polarization. These measurements in each instantaneous field of view
in a scan provide the simultaneous determination of the intensity, and
the degree and azimuth of linear polarization in all nine spectral
bands.
- More information: "http://www.giss.nasa.gov/data/rsp_air/specs.html"
[Summary adapted from the NASA/GISS home page]
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