Space
Shuttle Radar Images
STS-59
SRL-1
(Shuttle Radar Lab 1)
The first mission
flew over a 10 day period from April 9-20, 1994, and we acquired excellent
data over the entire region.
STS-59
Launch from Kennedy Space Center
The
SIR-C radar in orbit on STS-59
The graphic
above shows the data acquisitions for the first SIR-C mission. Some 10%
of the Earth's surface was images. Our data acquisition is the only blue
dot in central Africa.
This
graphic shows the actual data acquisition area.
Lake
Kivu is a left center, the gorilla reserve just above the number 15
The mission
returned 47 terabits of data (47 by 10^12 bits of data) or the equivalent
of 30,000 encyclopedia volumes. Each of the three radars generates
45 million bits of data per second. When all the radars are operating
they produce 225 million bits of data per second, or the equivalent of
45 simultaneously operating television stations. The raw data was
processed into images using JPL's digital SAR processor and by processors
developed by Germany and Italy for the X-SAR data. Apx. 66 million square
kilometers (26 million square miles) were imaged over ten days.
Endeavour's
Space Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) is not affected
by weather conditions making it the ideal tool for capturing images over
the cloudy and misty volcanoes that
the gorillas live in.
For more
information on radar imagery go to The
Nasa/JPL Imaging Radar Home Page
and
the SIR-C Mission website
Also see
the NASA Website
on the SIR-C launch and our project.
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April 13, 1994 Shuttle Radar
Images
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This image
shows only the X-SAR image. Since the radar energy is from a single wavelength,
each individual band is shown as a black and white image. Vegetation patterns
(such as the bamboo forest) are visible.
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The same X-SAR
image is shown with an inverted color table, which highlights different
aspects of the landscape. The two images are shown together below for comparison.
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Color composites
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False color
composites were then created by combining the three different bands (X
and two C bands) by assigning blue, green, and red to each of the grayscale
images. While these color composites are "'false' colors, and do not accurately
reflect the colors of the landscape, they do provide a much better ability
to differentiate between different vegetation zones, as you can see in
the image below. This false-color composite is created by displaying the
L-band radar HH (horizontal/horizontal polarity) return in red, the L-band
HV (horizontal/vertical polarity) return in green and the C-band HH (horizontal/horizontal
polarity) return in blue.
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SRL-1 DT 58.60,
171.10
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(data takes
58.60 and 171.10)
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click on the image for
a larger version
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You can download
a high resolution (8Mb) image here
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This was the
first Radar image acquired in April, 1994 by the Space Shuttle SIR-C Radar
. Lake Kivu is in black at the bottom. The Volcanos are clearly visible
in the center of the image in green. The pink areas with lines are intensive
agriculture.
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This is a false-color
radar image of Central Africa, showing the Virunga Volcano chain along
the borders of Rwanda, Zaire and Uganda. This area is home to the endangered
mountain gorillas. This C- and L-band image was acquired on April 12, 1994,
on orbit 58 of space shuttle Endeavour by the Spaceborne Imaging Radar-C/X-band
Synthetic Aperture Radar (SIR-C/X-SAR). Incidence angle was 44.2 degrees.
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The area is
centered at about 1.75 degrees south latitude and 29.5 degrees east longitude.
The image covers an area 58 kilometers by 178 kilometers (48 miles by 178
miles). The false-color composite is created by displaying the L-band HH
return in red, the L-band HV return in green and the C-band HH return in
blue.
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The dark area
in the bottom of the image is Lake Kivu, which forms the border between
Zaire (to the left) and Rwanda (to the right). The airport at Goma, Zaire
is shown as a dark line just above the lake in the bottom left corner of
the image. Volcanic flows from the 1977 eruption of Mt. Nyiragongo are
shown just north of the airport. Mt. Nyiragongo is not visible in this
image because it is located just to the left of the image swath. Very fluid
lava flows from the 1977 eruption killed 70 people. The large volcano in
the center of the image is Mt. Karisimbi (4,500 meters or 14,800 feet).
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This radar
image highlights subtle differences in the vegetation and volcanic flows
of the region. The faint lines shown in the purple regions are believed
to be the result of agriculture terracing by the people who live in the
region. The vegetation types are an important factor in the habitat of
the endangered mountain gorillas.
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Click here
for a larger version, or click on the image above.
CRSSA staff
and Dr. madry processed information from NASA's Space Shuttle, as well
as data gathered by Rwandan trackers using sophisticated Global Positioning
Systems (GPS) that read information from satellites, and existing files
to help create the
Geographic Information System (GIS) database
on the gorillas and their habitat.
This full resolution
image shows the region around the Goma airport. The airport is clearly
visible as a dark line at bottom left near lake Kivu. The road between
the airport and lake shows as a dark line, as does the road running from
the airport north. large structures appear as bright white dots, as these
are large radar reflectors.
This full resolution
image shows the northern portion of the reserve. The main road between
Rwanda and Uganda (from Ruhengeri, visible at lower right, to Kisoro Ugana)
is clearly visible at the right edge of the image. A small settlement with
buildings and structures is visible as dark areas at bottom center.
This full resolution
image shows the center portion of the reserve. The hagenia vegetation zone
on the slopes of Mount Karisimbi shows as a lighter green at bottom,
with the Mimulopsis and mixed forest above in a darker green. The agricultural
terracing is visible at right, with a settlement and structures at upper
right. The western border of the park is clearly marked.
This full resolution
image shows the southern portion of the reserve, centered on Mount Karisimbi
(14,787 ft). Agricultural terraces surround the reserve right up to the
boundary. These pink areas at bottom and right were originally part
of the reserve, but were turned over to agriculture, significantly reducing
the total area of the park and forcing the gorillas up into higher, colder,
wetter climates. In the reserve the bamboo (dark green at bottom)
, hagaenia forest (next), subalpine, and alpine (mountain tops) ecosystems
are clearly differentiated. You can see the boundary of Rwanda and
D. R. Congo (formerly Zaire) at left. A vegetation map that was produced
by our project is shown below. This was the first overall vegetation map
of the gorilla habitat.
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A comparison
of Muhavura (13,868 ft. or 4,227 m).
Muhavura is
the northeastern-most mountain in the reserve. Here we see the April'95
SIR-C radar image and a 1950's aerial photograph. The effect of 'layover'
is evident in the radar image, with the mountain 'leaning' to the right
(towards the direction of the Space Shuttle). The boundary of the park
is evident in both images, as well as the highly eroded nature of the sides
of the mountain, caused by the large amounts of annual rainfall.
Color
table inversion
This full resolution
image shows the northern portion of the reserve using the same three bands
but using an inverted color table. The main road between Rwanda and Uganda
is clearly visible at the right edge of the image. A small settlement with
buildings and structures is visible as dark areas at bottom center.
The
central portion of the area.
This full resolution
image shows the southern portion of the reserve, centered on Mount Karisimbi
(14,787 ft), again using the same three bands but using an inverted color
table. Agricultural terraces surround the reserve right up to the boundary,
and the bamboo, hagenia forest, subalpine, and alpine ecosystems in the
park are clearly differentiated.
The next
section contains images from the second flight of Endeavour in September,
1994.
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