In general more things give off infrared than visible light. In most cases only extremely hot objects (like stars) give off visible light. Cooler objects can be seen much more easily in infrared.
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Visible light is electromagnetic radiation (energy) in the spectrum between .4 and .7 micrometres. Infrared is in the spectrum between .7 and 300 micrometres. So, you have more potential data to gather with infrared.
The percent of EMR that is reflected and can be sensed by the satellite sensor in the visible spectrum is generally lower than infrared.
When you plot the spectrum ranges and the reflectance on a graph you notice there's more possible variation in the infrared spectrum. This means it's easier to identify spectral signatures (the reflectance at a set of wavelengths) of particular objects using the infrared spectrum.
To add a little more to the potential data, the EMR that actually arrives at the sensor is interrupted in certain wavelengths by atmospheric effects. Having a broader range of wavelengths also means you're more likely to find a wavelength that works well for satellite imagery.
The short of it is that satellite imagery is using infrared data is more likely to detect and differentiate between objects.
The percent of EMR that is reflected and can be sensed by the satellite sensor in the visible spectrum is generally lower than infrared.
When you plot the spectrum ranges and the reflectance on a graph you notice there's more possible variation in the infrared spectrum. This means it's easier to identify spectral signatures (the reflectance at a set of wavelengths) of particular objects using the infrared spectrum.
To add a little more to the potential data, the EMR that actually arrives at the sensor is interrupted in certain wavelengths by atmospheric effects. Having a broader range of wavelengths also means you're more likely to find a wavelength that works well for satellite imagery.
The short of it is that satellite imagery is using infrared data is more likely to detect and differentiate between objects.
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The major advantage is that chlorophyll is very reflective in the near and mid infrared. An experienced remote sensing/GIS technician can interpret and assess the health of vegetation in an area pretty quickly from multi-band false infrared aerial photography either on conventional film or from digital images, especially if imagery from different dates is available.
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Infrared light can pass right through objects that stop visible light entirely.
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A lot more objects in the universe give of infrared radiation than visible light, so an infrared satellite can search and see more things.