Signal to Noise Ratio

The signal to noise ratio is important for the design of remote sensing systems. All electronic systems have inherent noise, and the sensor must collect enough electronic information ("Signal") so that it stands out from the random noise. More signal can be collected by:

• Larger pixel size, integrating over a larger area on the ground.
• Lower spectral resolution, or larger channel/band sizes. If you merge "colors" there will be more energy. Black and white (panchromatic) sensors collect more energy than color sensors which divide the same amount of light in multiple categories, each of which must be measured separately. This is larger spectral bandwidth.
• Choosing shorter wavelengths, which provide more energy. The is more energy in the visible, than in the infrared, which in turn has more energy than the microwave.

Last revision 2/5/2005