Editing Forward-looking infrared (section)

==Etymology==
The term "forward-looking" is used to distinguish fixed forward-looking thermal imaging systems from sideways-tracking infrared systems, also known as "[[Push broom scanner|push broom]]" imagers, and other thermal imaging systems such as gimbal-mounted imaging systems, handheld imaging systems, and the like. Pushbroom systems typically have been used on aircraft and satellites.

Sideways-tracking imagers normally involve a one-dimensional (1D) array of pixels, which uses the motion of the aircraft or satellite to move the view of the 1D array across the ground to build up a 2D image over time. Such systems cannot be used for real-time imaging and must look perpendicular to the direction of travel.