Measuring weather

There are two kinds of satellites that watch the weather:

• Geostationary: These rotate at the same rate as Earth from 22,369 miles above the earth. This means they are "stationary" at the same point above the earth all the time making observations of the same part of the planet.
• Polar-orbiting: These orbit much lower at about 530 miles above earth and circle around Earth's north and south poles as seen in the image.

Being much further away, the geostationary satellites have a much larger field of view than the nearer polar-orbiting satellites. This provides information for large sections of the globe quickly, but there is a drawback to being so far away: detail. If you think of a satellite as a digital camera, more distant satellites will see the earth at a lower resolution than the closer polar orbiting satellites.

There are two Geostationary Operational Environmental Satellites, called GOES East and GOES West, that can capture images of most of the western hemisphere every 15-30 minutes. As such, they are very good at tracking the movements of weather systems.

Next page   -> remote observations, satellite

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