Spectral Bands
The wavelengths are approximate; exact values depend on the particular satellite's instruments:
- Blue, 450-515..520 nm, is used for atmospheric and deep water imaging, and can reach within 150 feet (50 m) deep in clear water.
- Green, 515..520-590..600 nm, is used for imaging of vegetation and deep water structures, up to 90 feet (30 m) in clear water.
- Red, 600..630-680..690 nm, is used for imaging of man-made objects, in water up to 30 feet (9 m) deep, soil, and vegetation.
- Near infrared, 750-900 nm, is used primarily for imaging of vegetation.
- Mid-infrared, 1550-1750 nm, is used for imaging vegetation, soil moisture content, and some forest fires.
- Mid-infrared, 2080-2350 nm, is used for imaging soil, moisture, geological features, silicates, clays, and fires.
- Thermal infrared, 10400-12500 nm, uses emitted radiation instead of reflected, for imaging of geological structures, thermal differences in water currents, fires, and for night studies.
- Radar and related technologies are useful for mapping terrain and for detecting various objects.
Read more about this topic: Multispectral Image
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