Yousef Rahimsouri - Department of Geology, Faculty of Science, Urmia University, Iran
Hamid Tavakkoly - Department of Geology, Faculty of Science, Urmia University, Iran
Reza Abbasi Nasirkandi - Department of Geology, Faculty of Science, Urmia University, Iran

Linear Spectral Unmixing (LSU) determines the relative abundance of materials that are depicted in multispectral or hyperspectral imagery based on the materials’ spectral characteristics. LSU has two constraint options: unconstrained or a partially constrained unmixing. In the unconstrained method, abundances may assume negative values and are not constrained to sum-to-unity (one). ENVI also supports an optional, variable-weight, unit-sum constraint in the linear-mixing algorithm. This allows you to define the weight of a sum-to-unity constraint on the abundance fractions. It also permits proper unmixing of MNF transform data, with zero-mean bands.

Linear Spectral Unmixing (LSU), ENVI