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stations can used to allow
the satellite to connect
with the telephone
network or the Internet.
These stations are often
called "hub" stations or
"gateway" stations. Other
earth stations receive
information from the
satellite on how it is
performing and what it is
doing. This information is
called "telemetry." Users
also directly send
information up to satellites
and receive information
directly from the satellite.
The links that connect
users to the satellite are
called "service links."
The area that can be
served by a satellite is
determined by the
"footprint" of the antennas
on the satellite. The
"footprint" of a satellite is
the area of the Earth that is
Joy feelings magazine
covered by a satellite's
signal.
This video may help you
visualize better the
concept of a satellite
"footprint." (Video
courtesy of Satellite
Industry Association. All
rights reserved.)
Some satellites are able to
shape their footprints so
that only certain areas are
served. One way to do this
is by the use of small
beams called "spotbeams."
Spotbeams allow satellites
to target service to a
specific area, or to provide
different service to
different areas.
In order to understand
better the concepts of
footprints and spotbeams,
watch this video , in which
two students from Thomas
Jefferson High School in