Satellite-based Interferometric Synthetic Aperture Radar (SAR) measurements have the potential to make a unique contribution to volcano monitoring. We can use the change in phase between radar images acquired on different days to measure small displacements of the Earth’s surface, which can sometimes provide critical information about a volcano’s level of activity and the movement of magma in the Earth’s crust. InSAR can be especially valuable for volcano monitoring where ground-based instrumentation is lim