Geoscience Reference
In-Depth Information
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Figure 3-2.
Platforms for manned photography of the Earth's surface. A. Discovery space shuttle as seen from the
International Space Station above the southwestern coast of Morocco; ISS026-E-032253, 7 March 2011. Modii ed
from NASA Human Space Flight; accessed online
http://spacel ight.nasa.gov/gallery/images/station/crew-26/html/
iss026e032253.html
>
January 2012. B. Challenger II light sport aircraft for low-height aerial photography. Overhead
wings and large open windows allow good views for the photographer. Photograph courtesy of W.S. Lowe.
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be appreciated fully; in stereoscopic images,
the full three dimensions become apparent.
• Size and height - Absolute size and height
are important clues that depend on scale of
the photograph. Always check photo scale
(GSD) for a guide to object size.
• Shadow - Shadows may be useful clues for
identifying objects, as seen from above.
Trees, buildings, animals, bridges and towers
are examples of features that cast distinctive
shadows. Shadows on the landscape also
help provide depth perception.
• Pattern - The spatial arrangement of dis-
crete objects may create a distinctive pattern.
This is most apparent for cultural features,
for example city street grids, airport runways,
agricultural i elds, etc.
• Texture - This refers to grouped objects that
are too small or too close together to create
distinctive patterns. Examples include tree
crowns in a forest canopy, individual plants
in an agricultural i eld, ripples on a water sur-
face, etc. The difference between texture and
pattern is determined largely by photo scale.
