a Polar Orbit?] [Inclinations]
A Polar orbit is a
particular type of Low
Earth Orbit. The only
difference is that a satellite in polar orbit
travels a north-south direction, rather than the
more common east-west direction.
Why use a Polar Orbit?
Polar orbits are
useful for viewing the planet's surface. As a
satellite orbits in a north-south direction, Earth
spins beneath it in an east-west direction. As a
result, a satellite in polar orbit can eventually
scan the the entire surface. Its like pealing an
orange in one piece. Around and around, one strip
at a time, and finally you've got it all. For this
reason, satellites that monitor the global
environment, like remote
sensing satellites and certain
satellites, are almost
always in polar orbit. No other orbit gives such
thorough coverage of Earth.
We say that a
polar orbit has an inclination, or angle, of 90
degrees. It is perpendicular to an imaginary line
that slices through Earth at the equator.