[remote sensing]
The sensitivity of a sensor to small fluctuations in the amount of energy in the electromagnetic spectrum. There are three aspects to this characteristic: 1) The sensor's bandwidth sensitivity (full width at half maximum, or FWHM) determines the range of wavelengths in the specific image band of the electromagnetic spectrum that the sensor can detect. 2) Typically, sensors have 8-, 11-, 12-, 14-, or 16-bit depth per band. The higher the bit depth, the higher the sensor's potential radiometric resolution. 3) The sensor's signal-to-noise ratio (S/N) describes the amount of signal resolution information within the band. For example, two sensors can each return an image containing 8 bits of information (256 possible grey levels), but one may have 60 S/N and the other 120 S/N, or double the amount of signal resolution information.