The AMSR-E sensor has 12 passive channels consisting of six dual
polarization frequency channels: 6 GHz, 10 GHz, 18 GHz, 36 GHz, and 89 GHz.
The spatial resolution of the data varies with frequency, with 6 GHz being the
coarsest and 89 GHz having the finest resolution. The high frequency channels
are designed for atmospheric observation, but can have utility for land and ice surface
observation if the atmospheric "interference" can be tolerated.
Enhanced resolution brightness temperature (Tb) images are generated for
each frequency and polarization using multiple orbits via the radiometer version of
the Scatterometer Image Reconstruction (SIR) algorithm (Long and Daum, 1998). Since there can be a wide
time-of-day effect on Tb, twice daily images are created based on the local time-of-day
of the passes. Generally, the local time-of-day of the data has a narrow window
(one or two hours, though the polar regions can have a larger span). Note that
changes in Tb between multiple passes can result in imaging artifacts, which typically
show up as high "noise" regions.
AMSRE image grids and projections are compatible with, and identical to, other SCP
image grids. Two image resolutions are used: one for the lower
frequency channels, with a finer resolution used for 89 GHz frequency channels.
Images are generated from the un-resampled recalibrated Tb masurements in the
data obtained from the National Snow and Ice Data Center (NSIDC).
Further information is available in the
AMSRE Enhanced Resolution Image Users Notes.