Satellites take pictures of clouds that move
across the earth, usually from 22,500 miles in space. There are many
types of satellite imagery; visible and infrared are popular. Visible
imagery is used when the satellite takes pictures of the clouds during
the day just like a regular camera. At night visible imagery is not
possible since the sun is not providing a light source for the picture.
Infrared radiation emitted by clouds is sensed by the satellite and then
converted to temperatures using mathematical equations. The temperatures
are related to the height of the clouds. Colder temperatures imply
higher cloud tops. Higher cloud tops may be representative of
thunderstorms
or fair weather cirrus clouds.
(back
to forecast help page)
