GreenRevolution
Gujarat, India
SatelliteImagery
Dams
Irrigation
Desertification
Figure 5
Spectral
Endmembers Used in Spectral Mixture Analysis for both Landsat MSS Scenes
The
spectral signatures of the endmembers used in both the northern (n) and southern
(s) Landsat MSS scenes are plotted above. Three endmembers (vegetation,
sand/soil, and shade) were found in either scene.
The
vegetation spectra for both the northern and southern scenes are very similar.
The
sand spectra differed significantly between scenes. The northern scene had very
bright sand along river beds, which allowed this endmember to possibly account
for some illumination effects as well as sand content in a pixel. The southern
scene had a darker dominant soil type.
The effects of scattering can be seen in the shade spectra of both scenes, as the higher values in the first two bands are almost entirely due to atmospheric effects. The shade endmember in the northern scene was found in the extremely dark volcanic soils abundant in this region and was barely distinguishable from the spectra of a deep reservoir in the same scene. Therefore this endmember accounted for not only shadowing and water, but dark soil as well. The shade in the southern scene was found in a deep reservoir.