WASHINGTON
-- The launch of NASA's Landsat Data Continuity Mission (LDCM)
satellite is scheduled for Monday, Feb. 11, from Space Launch Complex 3
at Vandenberg Air Force Base in California. Liftoff aboard an Atlas V
rocket is targeted to occur at the opening of a 48-minute launch window
at 1:02 p.m. EST (10:02 a.m. PST).
LDCM is a joint NASA and
U.S. Geological Survey (USGS) mission. It is the eighth satellite in the
Landsat series, which began in 1972 and will add to the longest
continuous data record of Earth's surface as viewed from space. LDCM
will extend global land observations that are critical in many areas,
such as energy and water management, forest monitoring, human and
environmental health, urban planning, disaster recovery and agriculture.
The LDCM News Center at NASA's Vandenberg Resident Office
opens Feb. 6. To speak with a NASA communications specialist there,
media representatives can dial 805-605-3051. For a recorded launch
status report, dial 805-734-2693.
Prelaunch and launch
activities will take place Feb. 8-11. U.S. journalists should fax their
accreditation requests on news organization letterhead to Kaylee Ausbun,
30th Space Wing Public Affairs Office at Vandenberg, at 805-606-4571,
or email kaylee.ausbun@us.af.mil. Requests must include full legal name,
date of birth and media affiliation. A government-issued photo
identification will be required for entry to Vandenberg.
A
prelaunch news conference and mission briefing featuring NASA and USGS
scientists will be held from 3-5 p.m. EST (12-2 p.m. PST) Friday, Feb.
8, in NASA's Vandenberg Resident Office. The briefing will be carried
live on NASA Television with question-and-answer capability available
from NASA field centers and via Twitter with the hashtag #askNASA.
On launch day, NASA TV coverage and commentary will begin at 10:15
a.m. EST (7:15 a.m. PST). Spacecraft separation occurs one hour, 17
minutes, 58 seconds after launch. A post-launch news conference will be
held approximately two hours after launch.
Live countdown
coverage also will be available online. Launch updates will begin on
NASA's launch blog at 10:15 a.m. EST (7:15 a.m. PST) Feb. 11. Coverage
features live updates as countdown milestones occur, as well as
streaming video clips highlighting launch preparations and liftoff. To
view the launch blog, visit:
NASA Goddard Space Flight Center in Greenbelt, Md., is responsible for
LDCM project management. Orbital Sciences Corporation built the LDCM
satellite. NASA's Launch Services Program at the agency's Kennedy Space
Center in Florida provides launch management. United Launch Alliance of
Denver, Colo., is NASA's launch service provider of the Atlas V 401
rocket. After launch and the initial checkout phase, the USGS will take
operational control of the satellite, and LDCM will be renamed Landsat
8.
For NASA Television downlink information, schedule information and streaming video, visit:
Landsat Senses a Disturbance in the Forest.
Landsat data for each year loops from 1984 to
2011 as we move across the changing landscape. Stops at a clear cut and
two types of insect outbreaks show how scientists use the numbers that
drive the color changes to understand forest dynamics. The colors
represent types of land; for example, blue areas are forests;
orange/yellow areas are agriculture; and purple areas are urban.
Credit: NASA/Goddard Scientific Visualization Studio
› Download hi-res video
Sensing a Disturbance in the Forest: New Landsat Imagery Tool Sees Insect Outbreaks From Space.
A new way of studying and visualizing Earth science data from a NASA and
U.S. Geological Survey satellite program is resulting in, for the first
time, the ability to tease out the small events that can cause big
changes in an ecosystem.
Called LandTrendr, this computer program is able to find patterns
previously buried within vast amounts of scientific data. Still in
development, it's already led to seeing for the first time in satellite
imagery an obscured, slow-moving decline and recovery of trees in
Pacific Northwest forests.
Comparing satellite data to ground data, scientists uncovered the cause.
"It was, as it turns out, bugs," says Robert Kennedy, a remote sensing
specialist at Boston University, who consulted with U.S. Forest Service
experts to confirm his observations.
The unexpected disturbance pattern showed a long slow decline of tree
health over years followed by slow regrowth. It emerged in several
areas, particularly near Mount Hood in the 1980s, peaking in 1992 when
regrowth began, and near Mount Rainier where the insect outbreak lasted
ten years from its onset in 1994 till the insects killed all the trees
and moved on in 2004.
Kennedy created the LandTrendr program specifically to work with data
from the NASA and U.S. Geological Survey (USGS) Landsat program.
Kennedy's new way of viewing Landsat imagery has already changed how the
Forest Service in the Pacific Northwest operates its yearly forest
monitoring program that uses ground stations, satellite imagery and
statistics to evaluate current conditions.
Kennedy says that LandTrendr works because of the unique nature of
Landsat data. The data embedded in images are a scientific record of the
Earth's surface that goes back 40 years. Each image, or scene, covers
an area 115 miles by 112 miles (185 kilometers by 180 kilometers) and
provides data for wavelengths of light reflected or emitted from the
Earth's surface, which scientists use to see, for example, forest
conditions not apparent in visible light. With the four-decade record,
they can compare images between years and see how the land changes with
time.
Studying big areas over many years means handling big data sets and
figuring out how to get all the data to work together for meaningful
comparisons. One challenge in particular is finding images from the same
time of year where the view of the ground is not hidden by clouds.
Kennedy's breakthrough was to combine cloud-free pixels from multiple
scenes of the same area collected over the growing season in late
summer. Then he compares the new images for each year to one another. By
breaking a scene down into smaller sized pixels, the cloud-covered
portions could be tossed away, but LandTrendr keeps the clean bits to
reveal the life history of each pixel.
"We're getting better data use out of what people think of as crummier
images," says Curtis Woodcock, a remote sensing specialist at Boston
University who employs a similar method to Kennedy to build an image of
the landscape out of Landsat data pixel by pixel.
What makes all this possible are two things: Computers are finally
powerful enough to process vast amounts of data, and Landsat data is now
available free of charge.
The Oregon Data Trail.
The Landsat program has been observing Earth's land surfaces
consistently since 1972, when the first Landsat satellite, what became
known as Landsat 1, went into orbit. Since then, it has compiled the
longest continuous satellite record of change across our planet. But a
left over pay-for-data policy from the commercialization of the program
in the 1980s and 90s meant scientists rarely looked at the year-by-year
evolution of a landscape. When the USGS began providing Landsat data for
no charge in 2008, looking at twenty-five years or more of data became
affordable as long as you had the computing power to handle it.
"Not that long ago the size of an individual Landsat scene would have
crippled most desk top computers," says Doug Morton, a physical
scientist at NASA's Goddard Space Flight Center in Greenbelt Md., who
uses Landsat to study changes in the Amazon and forests in Indonesia.
Now with processing power doubled or more, he says, it's no problem for
most desktop machines to handle a big scientific job.
When Kennedy first saw a yearly succession of moderate resolution
Landsat satellite images of a 13,000 square mile area near Portland,
Ore., it was a revelation. Says Kennedy, it was like looking at a pair
of air photos of a forested hillside offset so that with special
glasses, the image pops into three dimensional clarity. "You sort of
squint your eyes and it takes a while and all of a sudden you get that
moment -- boom! Oh, my god, it's a landscape!" he says. "I had that same
sense [of amazement ] when I first started looking at the time series
stuff."
The ability to scroll backward and forward through time and Kennedy's
new technique for creating single visualizations out of millions of bits
of data from hundreds of Landsat images has revealed not just the
patchwork of fire scars and clear cuts -- what he was originally looking
for when he partnered with the Forest Service -- but also the slow and
subtle changes that take place over many years, including pulses of
insect outbreaks.
"We did not expect that," says Kennedy. In the satellite imagery they
had found two kinds of insect signals. The first is a classic mountain
pine beetle outbreak. One near the Three Sisters volcanoes in Oregon
started in the late 1990s and early 2000s. The beetles attacked lodge
pole pines, the same species affected in outbreaks throughout British
Columbia and Colorado.
The second, subtler signal found near Mount Hood and Mount Rainier is
the western spruce budworm, an insect that moves into an area and eats
the needles off the trees. Losing its green growth doesn't necessarily
kill the tree, but it does put it under a lot of stress. If budworms
return in following years, trees will ultimately succumb to the
onslaught and die. Then the budworms, out of food, move on. And the
forest gradually recovers.
Kennedy says to confirm the satellite data, they hiked into areas with
recent known budworm outbreaks near Mount Rainier. With the decline and
regrowth patterns from the new maps in hand, Kennedy says, "we stand out
on the ground in the forest and look at all the dead trees and we
realize that we're actually starting to see something that we had never
been able to see before from space. It was very exciting."
In this flyover tour of the data set, Landsat
data for each year loops from 1984 to 2011 as we move from Redwood
National Forest in California north along the Cascade range to Seattle,
Washington, and back south along the Willamette Valley. The colors
represent types of land; for example, blue areas are forests;
orange/yellow areas are agriculture; and purple areas are urban.
Credit: Goddard's Scientific Visualization Studio
› Download hi-res video
he imagery produced by LandTrendr is a remarkable tool for looking at
change over time, says Woodcock. But what he really wants to see is a
move from the retrospective to the real time. He says, "The goal in the
long run is to be able to provide land managers information on what's
happening as it's happening." It's a process, he says, that's just
getting started.
"That ability to read the story of the landscape is something that the
Landsat archive allows us to do like none other," says Doug Morton of
NASA Goddard. NASA and the USGS will continue providing the means to see
it with the next satellite in the Landsat series, to be called Landsat
8, scheduled to launch in early 2013.
To learn more about the Landsat program, visit:
Ellen Gray
NASA's Goddard Space Flight Center, Greenbelt, Md.
NASA
Guillermo Gonzalo Sánchez Achutegui
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