home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
PC Media 4
/
PC MEDIA CD04.iso
/
nasa
/
sc-oberh.txt
< prev
next >
Wrap
Text File
|
1995-02-23
|
3KB
|
63 lines
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE: (818) 354-5011
PHOTO CAPTION P-43930
April 17, 1994
Oberpfaffenhofen X, C & L-band
This is a false-color, three-frequency image of the
Oberpfaffenhofen supersite, southwest of Munich in southern
Germany, which shows the differences in what the three radar
bands can see on the ground. The image covers a 27- by 36-
kilometer (17- by 22-mile) area. The center of the site is 48.09
degrees north and 11.29 degrees east. The image was acquired by
the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar
(SIR-C/X-SAR) onboard space shuttle Endeavour on April 13, 1994,
just after a heavy storm which covered the all area with 20
centimeters (8 inches) of snow. The dark area in the center of
the image is Lake Ammersee. The two smaller lakes above the
Ammersee are the Worthsee and the Pilsensee. On the right of the
image is the tip of the Starnbergersee. The outskirt of the city
of Munich can be seen at the top of the image. The
Oberpfaffenhofen supersite is the major test site for X-SAR
calibration and scientific experiments such as ecology, hydrology
and geology. This color composite image is a three-frequency
overlay. L-band total power was assigned red, the C-band total
power is shown in green and the X-band VV polarization appears
blue. The colors on the image stress the differences between the
L-band, C-band and X-band images. If the three frequencies were
seeing the same thing, the image will appear in black and white.
For example, the blue areas corresponds to area for which the X-
band backscatter is relatively higher than the backscatter at L-
and C-band; this behavior is characteristic of clear cuts or
shorter vegetation. Similarly, the forested areas have a reddish
tint. Finally, the green areas seen at the southern tip of both
the Ammersee and the Pilsensee lakes indicate a marshy area.
-----
Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar
(SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The
radars illuminate Earth with microwaves allowing detailed
observations at any time, regardless of weather or sunlight
conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band
(24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency
data will be used by the international scientific community to
better understand the global environment and how it is changing.
The SIR-C/X-SAR data, complemented by aircraft and ground
studies, will give scientists clearer insights into those
environmental changes which are caused by nature and those
changes which are induced by human activity. SIR-C was developed
by NASA's Jet Propulsion Laboratory. X-SAR was developed by the
Dornier and Alenia Spazio companies for the German space agency,
Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the
Italian space agency, Agenzia Spaziale Italiana (ASI), with the
Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v. (DLR),
the major partner in science, operations and data processing of
X-SAR.
#####