Satellite Shots

[uwochris]

Hey guys,

Can someone explain the difference between a Satelitte Visible and a Satellite Infrared map?

Thanks in advance.

 

[EagleRJ]

A visible image is simply a video image of the ground- just like if you were looking through binoculars from the Space Shuttle. Visible images obviously aren't available at night- if you can't see the ground, neither can the satellite. On visible loops taken in the morning or evening, you can also see the terminator (the sunrise or sunset boundary) moving across the ground.

Infrared images are used for nighttime data and to get additional data about precipitation. They're also taken with a camera on the satellite, but one that is sensitive to the infrared spectrum and can show differences in heat. In an infrared image, cooler clouds are bright white, and warmer areas are darker. The brightest parts of an infrared image are the cold tops of thunderstorms.

 

[Typhoon1244]

(Geography-major to the rescue!)

"Visible" means just what it says, an image made using visible light. Just like a conventional camera.

"Infrared" typically means color infrared, a type of film that was developed during W.W. II. It causes anything containing chlorophyl to show up bright red. Man-made objects (bunkers, tanks, roads, etc.) tend to be shaded gray or silver.

Of course, infrared can also be thermal infrared. The most common TI imagery shows increasing levels of thermal energy as increasingly lighter shades of gray/white.