Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) Imagary from NASA/JPL

The Space Radar Laboratory-1 (SRL-1) was a payload launched with the
Space Shuttle &Endeavor& (STS-59) on April 9, 1994. The SRL-1
comprises two elements: a suite of radar instruments called the
Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar
(SIR-C/X-SAR), and the Measurement of Air Pollution from Satellite
(MAPS) instrument. The SIR-C/X-SAR radar was jointly developed by NASA
with DARA of Germany and ASI of Italy.

The SIR-C/X-SAR instrument consists of 3 bands: C-Band (0.235 m),
L-Band (0.058 m), and X-Band (0.031 m). Typical resoultion was 30 x 30
meters.

The Space Radar Laboratory-2 (SRL-2) was launched with the Space
Shuttle &Endeavor& (STS-68) on September 30, 1994. As with SRL-1,
SRL-2 consists of the SIR-C/X-SAR radar instruments and the MAPS
instrument.

Images obtained from the SIR-C/X-SAR are available from the NASA JPL
Imaging Radar Page:

http://www.jpl.nasa.gov/radar/sircxsar/

and

http://southport.jpl.nasa.gov/

The objectives of the SIR-C/X-SAR were to provide information about
the Earth's land surfaces including vegetation coverage, snow pack
extent, wetlands, geologic features, volcanic processes, ocean wave
heights and wind speeds over the oceans. The most useful feature of
imaging radar is its ability to make measurements over any region at
any time regardless of weather or sunlight. The SIR-C/X-SAR is a
synthetic aperture radar that transmits pulses of microwave energy
from the Shuttle toward Earth and measures the strength and time delay
of the energy scattered back to the SIR-C/X-SAR antenna. The motion of
the Shuttle between the transmission of the beam and the reception of
the backscattered radiation is used to &synthesize& or create an
antenna (aperture) much longer than the actual antenna. This results
in finer resolution images.

The SIR-C/X-SAR scientific team has identified more than 400 sites
where data was taken. Nineteen of the sites are designated
&supersites&, making them priority targets for scientific
investigations. There are an additional 15 backup supersites. The
supersites were chosen to represent different environments within each
scientific discipline. The following are areas of investigation and
supersites for the SRL mission:

* Ecology: Manaus, Brazil; Raco Mich.; Duke Forest, N.C.; Central Europe.

Radar images will be used to study land use, vegetation extent, effects of
fires, floods, and clear-cutting, soil moisture, forest dynamics.

* Hydrology: Chickasha, OK; Otztal, Austria; Bebedouro, Brazil; Montespertoli,
Italy

Radar images will be used to study snow cover, wetlands, and soil moisture
patterns.

* Oceanography: Gulf Stream, Northeast Atlantic Ocean; Southern Ocean

Radar images to study surface and internal waves, oceanic wind speed,
and currents.

* Geology: Galapagos Islands; Sahara Desert; Death Valley, CA; Andes Mountains,
Chile; Mount Pinatubo

Radar imagery to map geologic structures, areas of erosion and volcanic
activity, paleoclimatic sites in arid regions, geologic evidence of past
climate changes, surface roughness.