by David Murphy
An Infrared Satellite image is produced using information collected by infrared sensors aboard a satellite. These sensors detect the temperature of the clouds below and assign different shades of white or gray, accordingly. Computers then draw a picture of the cloud cover, with each brighter shade of gray representing a colder temperature.
How can this be useful? First of all, the completed image mirrors an actual photograph of clouds and can be generated any time of day or night. Between sunset and sunrise, this is the only way to produce a new image of cloud cover. But an infrared image of clouds also tells you things a regular photo can not. By showing the colder areas, the image points-out clouds that are thicker, taller and may be more prone to producing precipitation.
Sometimes, the computer even adds oranges and reds to show especially cold areas. On Action News, some of our hurricane graphics use this orange and red color scheme, indicating particularly strong sections of a tropical storm.
In addition, infrared satellite sensors record sea surface temperatures and produce water vapor images, which are also useful in analyzing the atmosphere.