Relationship between the linear and non-linear spectral unmixing.

Both approaches try to deal with non-linearities in the problem. However, the linear spectral unmixing with higher moments tries to deal with the non-linearities that arise due to the intra-class variability, while the non-linear spectral unmixing tries to deal with non-linearities that arise due to the nature of the physical processes involved. Ideally both approaches should be combined. For a comprehensive review on both approaches see M. Petrou, Chapter 4 in the book ``Information Processing for Mixed pixel Classification in Remote Sensing'', Remote Sensing (code 3999), C H Chen, editor, World Scientific, ISBN 981-02-3737-5, pp 69-83.