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Archive of Webcast
Pre-Launch
Mission Overview
Mission Background Video
This is a RealMedia Video file and requires download and installation of
RealPlayer (above).
To extract the most accurate and useful information
from radar echoes, scientists need data that are calibrated. Desert
areas, such as Death Valley, provide an ideal background calibration
because they are relatively smooth and vegetation free.
This is a computer generated view of the Shuttle Radar Topography Mission (SRTM)
scheduled to fly in January 2000. SRTM will re-use the same radar
instrument that
comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar
(SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in
1994.
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The Shuttle Radar Topography Mission (SRTM) uses radar
instruments to obtain the most complete, near-global high-resolution
database of the Earth's topography.
The shuttle, (STS-99)
with an instrument called an imaging
radar, will be used to provide the most precise "picture"
ever of Earth's land surface. The radar will bounce signals
off the surface; these signals will be received by two
onboard antenna systems and combined by computers at
a ground facility to produce three-dimensional (3-D)
images. SRTM consists of a specially modified radar system that will fly
onboard the space shuttle
during an 11-day mission. This radar
system will gather data that will
result in the most accurate and complete
topographic map of the Earth's surface that has ever
been assembled.
Traditionally, topographic maps have been generated from stereo pairs of
photographs acquired from high-altitude aircraft and satellites. However,
such optical systems
cannot penetrate the cloud cover that blankets nearly 40 percent of the
Earth's surface. In some tropical regions the cloud cover is virtually
continuous and, as a result,
significant portions of our planet's surface have never been mapped in
detail.
Poster Images Courtesy of Ball Aerospace &
Technologies Corp.
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Archive of Webcast
Mission Status during 11-day orbit.
The
mast, which was developed using the design
for the truss
structure of
the International Space Station, will extend sideways from the orbiter's
cargo bay.
SRTM will use single-pass interferometry,
which means that the two images will be
acquired at the same time -- one from the radar antennas
in the shuttle's payload
bay,
the other from the radar antennas at the end of a 60-meter (200-foot) mast
extending from the shuttle. Combining the two images produces a single 3-D
image.
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The mission is a partnership
between NASA and the National Imagery and Mapping Agency (NIMA). In
addition, the German and Italian space agencies are
contributing an experimental high-resolution imaging
radar system. Analysts will use the SRTM data to generate
3-D topographic maps called digital elevation models.
 These digital topographic maps can be combined
with other data for analysis.
The SRTM data will also be used to generate digital elevation maps of
Earth's surface that
scientists will use to study planetary geophysics,
hydrologic drainage system modeling, more realistic flight simulators for
military aircraft, as well as commercial uses like better locations for
cellular phone towers and improved
maps for backpackers.
The system will be launched in a stowed, compact configuration. When the
shuttle reaches orbit, the mast will deploy, creating a 60-meter-baseline,
fixed-length
interferometer at both C-band and X-band frequencies. The X-band
interferometer has been supplied by the German and Italian space agencies.
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February
15 Panel
of Guests
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Archive of Webcast
Mission follow-up.
Three sided corner reflectors.
Corner reflectors are passive devices that reflect the radar signal in a
concentrated, well understood fashion. When these bright reflections are
analyzed in the radar image, their expected brightness can be used to
adjust the measured brightness, calibrating the rest of the image.
Surveying the location and elevation of the reflectors helps check the
geometric accuracy of the SRTM maps, as well.
Charles Morris
Visit the
Collector Site
with Charley White
and Charles Morris
This is a RealMedia Video file and requires download and installation of
RealPlayer (above).
Data sufficient to produce a rectified, terrain corrected, C-band
(5.6
centimeters wavelength) radar
image mosaic of 80
percent of Earth's land surface at 30 meter resolution.
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 Astronaut Janice Voss spent 11-days in space and will join us by
phone during the webcast.
It will take one to two years to process
the
SRTM data to create the digital elevation maps. However,
during the mission a portion of the data
will be sent back to Earth and visualizations of preliminary
digital elevation maps will be made from
these data. You can read about these products in the
Mission Products Summary.
During the mission, you will be able to
click on a section of this map to see the mission
products that are available in that
region. The resulting data formats will be compatible
with standard cartographic data-analysis software and
tailored to the needs of the civil, military, and scientific
user communities. Much of the data from the mission
will be made available to these users in accordance with
release guidelines mutually developed by NIMA and
NASA. SRTM data will be collected over all land surfaces that lay between
60 degrees north
latitude and 54 degrees south latitude. That's about
80% of all the land on the Earth.
The map
to the left shows all the regions where data will
be collected.
To learn more about the types of data products collected during the
flight: Click
Here.
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Related URLs for more information on this event:
SRTM Mission Information-http://www.jpl.nasa.gov/srtm/
SRTM Mission Information- http://www.jpl.nasa.gov/srtm/factsheet_pub.html
STS-99 Launch and Shuttle Information- http://www.ksc.nasa.gov/shuttle/missions/sts-99/mission-sts-99.html
Responsible NASA Quest Contact Kate Weisberg
LTC Project Manager.
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