Visible (top), thermal infrared daytime (middle) and thermal infrared nightime
(bottom) view of Atlanta, GA.
In the thermal images, white is the warmest followed by red, yellow, green and blue.
Notice the oval structure in the lower left and how the south sun facing side (towards
the right of the image) which is the warmest area during the day is also the
warmest area at night - showing how the structure retains the daytime heat.
Satellites use infrared sensors to monitor deforestation and
fires in the
Amazon Basin and in other areas of the world. For example, Brazil's
forestry service uses the thermal imaging capabilities of the USDA Forest
FireMapper to detect illegal logging in the Amazon basin. Heat
sensing infrared cameras are also used to detect
thermal pollution in rivers,
oil and chemical spills,
septic leaks, buried waste and to monitor
smoke stack emission and waste water. Infrared cameras onboard helicopters
are used to monitor river temperatures to assist efforts to improve
In California, home to some of the worlds most stringent air pollution
control programs, state officials are studying the use of infrared light as
part of an enhanced vehicle inspection and maintenance program to detect
and repair high polluting vehicles. Remote sensing will use an infrared
beam to instantaneously gauge the level of
tailpipe emissions from a
passing vehicle, in order to detect high-polluting vehicles, and facilitate
Data from airborne infrared cameras have been used by NASA to study the
heat distribution in urban areas. Such information is helping city
planners to reduce ozone levels and showing where to plant trees. For
example, NASA and school children in Atlanta recently teamed up on a
project to study how
trees help keep cities cool.
Visible light (left) and infrared (right) views of Baton Rouge, LA. The
yellow and red colors denote warmer areas, and correspond with roads and
buildings. The cooler blue and green areas correspond with water and