2009 Annual Report - NASA Airborne Science Program

SWOT
Science Focus:
HQ Sponsor:
PI:
Water and Energy Cycle
ESTO
Moller
The Surface Water and Ocean Topography mission
(SWOT) is recommended by the NRC decadal
survey to satisfy the elevation mapping requirements
of two communities: surface water hydrology, and
ocean surface topography. The primary instrument
is a Ka-band Radar Interferometer (KaRIN) capable
of simultaneously meeting coverage, accuracy and
resolution requirements of both communities and
enhances greatly the science achievable from a
traditional profiling altimeter. The introduction of
this new approach introduces additional algorithmic,
characterization and calibration/validation needs
that can be addressed through focused airborne
campaigns in conjunction with traditional ocean
altimeter calibration/validation measurements and
existing and planned surface water gauge networks.
Surface water phenomenology presents some of the
more immediate measurement and characterization
questions due to the diversity of terrestrial water
environments coupled with a paucity of relevant
measurements. A recent (April 2009) opportunity
arose to collect Ka-band data over terrestrial water
bodies when the Glacier and Land Ice Surface
Topography Interferometer (GLISTIN) (developed
as a proof-of-concept sensor on the Gulfstream III
under the NASA International Polar Year program
– discussed elsewhere) transited to Greenland. En
route to Greenland via North Dakota, data were
collected in support of SWOT by rolling the G-III
and collecting near-nadir backscatter profiles over
local water bodies. Selected in collaboration with
USGS and academic colleagues, these sites included
Red River, Missouri River, Prairie Potholes, Devils
Lake and the Big Bog. Flying into Thule, SWOT
data was also collected over sea ice as a target of
opportunity. These data will provide valuable
backscatter statistics and for developing a land/water
classification including over vegetated water.
Figure 12:
Ka-Band antenna, funded by ESTO as part of
GLISTIN project.
For more information, visit http://decadal.gsfc.nasa.
gov/swot.html
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