qSatellite instruments measure radiation that the Earth and the atmosphere reflect, scatter,
transmit, and emit.
qThese instruments are called radiometers.
qThere are two types of radiometers:
q(1) Visible: measure the amount of
visible light from the Sun that is reflected back to space by the earth’s surface or by clouds.
q(2) Infrared: measures the amount
of infrared radiation emitted by Earth’s surface or clouds.