Endmember

Most significant is the observation that the vaporous for the more volatile end member occupies a decreasingly smaller portion of the diagram as the other end member becomes less volatile. Ultimately, when the less volatile end member is essentially involatile, the vaporous of the volatile end member may become microscopically small.

Source: wiktionary

The physicochemical processes that control the estuarine filter must therefore be considered to operate in terms of a framework involving particulate-dissolved recycling associated with three estuarine end-members, i.e. river water, sea water (which may consist of more than one component end-member), and sediments.

Source: wiktionary

In real estuaries, river water and seawater seldom mix together directly as endmembers. Rather, mixing takes place in a continuous manner that may be approximated by a series of water types, each of which has a salinity close to that of its neighbours.

Source: wiktionary

The Linear Mixing Model (LMM) assumes that the spectral signature of one pixel of the hyperspectral image is a linear combination of the endmember spectra corresponding to the aggregation of materials in the scene due to reduced sensor spatial resolution. Given the endmembers, unmixing algorithms compute the abundance coefficients providing sub-pixel resolution segmentations of the image.

Source: wiktionary