- The most common sensor is the photographic
camera. In this case, light sensitive film records reflected
light energy in the form of black and white or colour images.
- Multi-spectral scanners are used
to record visible light electronically as digital images. Scanners
can also detect non-visible energy eg thermal infrared (to detect
heat) and ultra-violet energy (to detect materials such as oil
on the sea surface).Examples of multispectral scanners include
Landsat and Spot.
- Meteological satellites e.g. NOAA
- Radar systems make use of microwave
energy and generate images from the reflected signals. Radar scanners
have the advantage of being able to see through cloud cover. e.g.
Synthetic Aperture Radar (SAR) or Side Looking Airborne Radar
(SLAR).
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SPOT satellite
Thematic Mapper satellite
Multi Spectral Scanner satellite
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