The dramatic improvement in access to satellite imagery and data processing tools makes it possible to observe deformations of the Earth's surface in near real time. Remote sensing imagery is a powerful, reliable, and spatially dense source of information that can be used to understand the Earth and its surface manifestations as well as to mitigate natural hazards.This book provides a comprehensive analysis of the methodological approaches developed to measure surface displacements using synthetic aperture radar (SAR) or optical images, and their applications in monitoring major geophysical phenomena. The first part presents the foundations of radar interferometry (lnSAR) and image correlation as well as the latest developments. The second part reviews the applications of these methods to geophysical phenomena and anthropogenic activities causing deformations of the Earth's surface.@en