Whisk broom scanner
Encyclopedia
A whisk broom or spotlight sensor (across track scanner) is a technology for obtaining satellite
images with optical cameras. It is used for passive remote sensing from space. In a whisk broom sensor, a mirror scans across the satellite
’s path (ground track
), reflecting light into a single detector which collects data one pixel
at a time. The moving parts make this type of sensor expensive and more prone to wearing out. Whisk broom scanners have the effect of stopping the scan, and focusing the detector on one part of the swath, typically capturing greater detail in that area. This is also called a close look scanner, comparable to a telephoto lens on a camera.
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
images with optical cameras. It is used for passive remote sensing from space. In a whisk broom sensor, a mirror scans across the satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
’s path (ground track
Ground track
A ground track or ground trace is the path on the surface of the Earth directly below an aircraft or satellite. In the case of a satellite, it is the projection of the satellite's orbit onto the surface of the Earth .A satellite ground track may be thought of as a path along the Earth's surface...
), reflecting light into a single detector which collects data one pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
at a time. The moving parts make this type of sensor expensive and more prone to wearing out. Whisk broom scanners have the effect of stopping the scan, and focusing the detector on one part of the swath, typically capturing greater detail in that area. This is also called a close look scanner, comparable to a telephoto lens on a camera.
External links
- Earth Observing-1 (NASA), with animated whisk broom and push broom illustrations