Suomi Virtual Museum Interpreting Satellite Infrared Images.
All objects emit electromagnetic radiation.
The infrared radiometers on satellites measure radiation with wavelengths of 11 micrometers. For easy interpretation, the radiant energy measured by infrared radiometers is converted to a temperature. Cold objects are white and hot surfaces appear black. Time sequences of infrared images are animated and shown on television news stations. Here is an interactive exercise that demonstrates the relation between cloud altitude and what is viewed by the satellite.