The Wishart Wizard is a graphical user interface (GUI) implemented in IDL as an extension for the remote sensing image analysis environment ENVI. It provides a simplified and user-friendly platform for performing multivariate change detection with bitemporal polarimetric SAR imagery. The change detection procedure implemented exploits the complex Wishart distribution of polarimetric SAR image observations in look-averaged covariance matrix format in order to define a per-pixel change/no-change hypothesis test. It includes approximations for the probability distribution of the test statistic, and so permits quantitative significance levels to be quoted for change pixels. In addition, an improved multivariate method is used to estimate the equivalent number of looks (ENL) of the look-averaged images, which is a critical parameter of the hypothesis test.
If SARscape is licensed in the ENVI environment, the Wizard accesses the SARscape API at the IDL scripting level to expose only that functionality necessary for the change detection analysis, thus guiding the user and simplifying the processing chain. If SARscape is not present, open source alternatives for the required preprocessing are available and are described in this documentation.