Interferometric Synthetic Aperture Radar (InSAR) is an active source microwave imaging technique capable of resolving fine-resolution deformation of the Earth’s surface at centimetric to millimetric precision. InSAR has been successfully used to generate high-resolution digital elevation models of the Earth’s surface topography, measure crustal deformation associated with volcanic deformation, post-seismic and co-seismic deformation, ground motion associated with landsliding, and glacial flow velocities. In recent years, considerable developments have been made towards the study of permafrost freeze thaw and degradation from InSAR observations. In this talk, I will present several techniques in the fields of InSAR and polarimetric SAR (PolSAR) that can be leveraged to resolve fundamental properties of permafrost and the active layer in periglacial landscapes, with a focus on permafrost-wildfire interactions and surface hydrology. I will also discuss emerging methods of leveraging nuisance terms (e.g., interferometric phase noise, phase nonclosure) for environmental retrievals of soil moisture, vegetation canopy water content, and wildfire burn severity.