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Applications Announcements
- The Early Adopter Program deadline has been extended to October 24, 2013. Read more...
- Joint Vegetation Tutorial with Landsat 8, May 7-8, 2014. Read more...
MABEL takes flight for summer campaign!
From its new berth beneath the high-flying Proteus aircraft, MABEL - the Multiple Altimeter Beam Experimental Lidar - kicked off a campaign this week along the U.S. Eastern Seaboard, measuring the height of tree canopies, buildings and other features with several flights from NASA's Langley Research Center in Hampton, Va.
MABEL takes these elevations by pulsing a laser 5,000 times a second. Each pulse contains millions of photons that travel from the aircraft, reflect off Earth's surface and return to the satellite. Only a handful of photons actually make it back to MABEL, but the instrument is sensitive enough to detect single photons. By combining the photon's precisely timed arrival and the instrument's GPS position, programs can calculate the distance the light travelled and the elevation of the surface below.
One of MABEL's goals is to help engineers working on the upcoming ICESat-2 satellite mission test models for that satellite's laser altimeter, said instrument lead scientist Bill Cook. MABEL will also gather data to enable scientists develop algorithms for ICESat-2's measurements of vegetation canopy height and inland water levels.
The test flight on Wednesday and the science flight on Thursday is showing great initial data. The next flight is planned for this evening, September 20, 2013.
We passed!
On Sept. 5, 2013, ICESat-2 passed its Ground Systems Critical Design Review, or CDR. An independent review board met Sept. 3-5 at Goddard Space Flight Center in Greenbelt, Md., to examine details of the entire design of the mission's ground system, including the Mission Operations Center, the Instrument Support Facility, and the Science Investigator-led Processing System.
These play key roles in the mission, including receiving data from the satellite and processing it so researchers can measure the height of ice sheets, tree canopies, glaciers and more. With this successful CDR, the ground systems team can start implementing its plans.
Latest satellite image
Credits: Satellite image courtesy of Orbital
Earth image illustrating AMSR-E sea ice courtesy of the NASA Scientific Visualization Studio
NASA Begins Airborne Campaign to Map Greenland Ice Sheet
Summer Melt
For the first time, a NASA airborne campaign will measure changes in the
height of the Greenland Ice Sheet and surrounding Arctic sea ice produced by a
single season of summer melt.
NASA's C-130 research aircraft flew from the Wallops Flight Facility in
Wallops Island, Va., to Greenland Wednesday where they will conduct survey
flights to collect data that will improve our understanding of seasonal melt and
provide baseline measurements for future satellite missions. Flights are
scheduled to continue through Nov. 16.
The land and sea ice data gathered during this campaign will give researchers
a more comprehensive view of seasonal changes and provide context for
measurements that will be gathered during NASA's ICESat-2 mission, which is
scheduled for launch in 2016.
"The more ground we cover the more comparison points we'll have for
ICESat-2," said Bryan Blair of Goddard Space Flight Center in Greenbelt, Md.,
principal investigator for the Land, Vegetation and Ice Sensor, or LVIS.
Warm summer temperatures lead to a decline in ice sheet elevation that often
can be significant in low-lying areas along the Greenland coast. In past years,
the Jakobshavn Glacier, located in the lower elevations of western Greenland,
has experienced declines of nearly 100 feet in elevation over a single summer.
Higher elevations farther inland see less dramatic changes, usually only a few
inches, caused by pockets of air in the snowpack that shrink as temperatures
warm.
"Surface melt is more than half of the story for Greenland's mass loss," said
Ben Smith, senior physicist at the University of Washington's Advanced Physics
Laboratory, Seattle, and member of the science team that selected flight lines
for this campaign. The rest of Greenland's mass loss comes from ice flowing
downhill into the ocean, often breaking off to form icebergs, and from melting
at the base of the ice sheet.
Researchers will measure ice elevation using the LVIS laser altimeter and the
LVIS-GH, a new, smaller version designed to fly on NASA's Global Hawk unmanned
aerial vehicle. LVIS and LVIS-GH will measure separate but overlapping swaths
of the ice from an altitude of 28,000 feet.
The C-130 carrying both instruments will fly out of Thule and Kangerlussuaq,
Greenland, allowing researchers to sample both high- and low-elevation ice and a
variety of geographic areas.
"We plan to concentrate our flights on areas northwest, southeast and
southwest Greenland and the Arctic Ocean," said Michelle Hofton, LVIS mission
scientist at Goddard and the University of Maryland, College Park. "The
measurements we collect along lines sampled in IceBridge's spring 2013 Arctic
campaign will allow scientists to assess changes over the summer."
Flying from Thule also will allow mission scientists to gather data on Arctic
sea ice shortly after it reaches its annual minimum extent. This will help
researchers get a clearer picture of what happens over the summer. It also will
help researchers gather new data on snow covering sea ice when combined with
information collected by the European Space Agency's CryoSat-2 polar-monitoring
satellite. LVIS detects the snow surface while CryoSat's radar sees through snow
to find the top of the ice. Researchers can combine these measurements to
calculate snow depth.
"This will be crucial for assessing the snow cover on sea ice during a very
different time of year," said Nathan Kurtz, sea ice scientist at Goddard.
For more information about NASA's IceSat-2 satellite, visit:
NASA:
Guillermo Gonzalo Sánchez Achutegui
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