Learn how satellites mounting SAR sensors are used to detect ground movement to millimeter precision.

This section describes how SAR systems acquire radar images, the basic principle of interferometry (on which all successive algorithms are based) and the evolution of the algorithms used to extract ground deformation data from the SAR images. See a description of the latest algorithm SqueeSAR™.

SAR satellites acquire images of the Earth’s surface by emitting radar signals and analyzing the reflected signal. A typical SAR image is 100 x 100 km and is regularly acquired over the same area.

As SAR satellites continuously circumnavigating the globe, a number of SAR images can be collected for the same area over time. By processing the SAR dataset for ground movement, the evolution of ground deformation can be extracted that can be useful for many applications.