Change Detection in Dual Polarization Sentinel-1 Data With Wilks’ Lambda

When the covariance matrix formulation is used for multilook polarimetric synthetic aperture radar (SAR) data, Wilks’ Lambda can be used for change detection between acquisitions at two time points. We briefly describe the theory for dual polarization, diagonal only data. A case study illustrates the technique on Sentinel-1 C-band data covering the international Frankfurt Airport. We successfully detect change including direction of change in the sense that Wilks’ Lambda shows whether radar signal increases or decreases over time.