Overview of This Tutorial - Department of Geosciences

Tutorial: Hyperspectral Signatures and Spectral Resolution
Spectral Resolution
Spectral resolution determines the way we see individual spectral features in materials measured from imaging
spectrometry. Many people confuse the terms
spectral resolution and spectral sampling . These are very
different.
Spectral resolution refers to the width of an instrument response (band-pass) at half of the band depth, or the
full width half maximum (FWHM). Spectral sampling usually refers to the band spacing - the quantization of
the spectrum at discrete steps - and may be very different from the spectral resolution. Quality spectrometers
are usually designed so that the band spacing is about equal to the band FWHM, which explains why band
spacing is often used interchangeably with spectral resolution.
The exercises that follow compare the effect of the spectral resolution of different sensors on the spectral
signatures of minerals. The graph below shows the modeled effect of spectral resolution on the appearance of
spectral features for Kaolinite.
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ENVI Tutorial: Hyperspectral Signatures and Spectral Resolution