Glossary
The vocabulary of hyperspectral Earth observation, explained without the hand waving.
Fundamentals
05Ground sample distance
The size of one pixel on the ground, why it is not the same as resolution, and what you give up spectrally to make it smaller.
Hyperspectral vs multispectral
Both measure reflected light in bands. The difference is how many bands, how narrow they are, and whether they form a continuous curve you can interpret as chemistry.
Spectral absorption feature
The dips in a reflectance curve where a material absorbs specific wavelengths. Their position and shape are what make minerals identifiable rather than merely visible.
What is a spectral library
A curated set of reference spectra measured under controlled conditions. It is the lookup table that turns an unknown pixel into a named material.
What is surface reflectance
The difference between what the sensor measured and what the ground actually is, and why atmospheric correction sits between them.