Synthetic aperture radar (SAR) interferometry, or simply InSAR, is a remote sensing technique utilising the phase difference between two or more complex-valued SAR images. Most modern SAR systems are capable of measuring both the intensity and the phase of the reflected signal, where the latter carries information about the distance travelled by the signal. Consequently, the phase difference measured between two SAR images is determined by the geometry and timing of the individual SAR acquisitions. Different geometric and temporal configurations enable different applications. If the SAR acquisitions are made from different angles and without significant temporal change of the scene, InSAR can be used to create digital elevation models (DEMs) of the Earth, as demonstrated by the NASA/JPL Shuttle Radar Topography Mission (SRTM). If the individual SAR acquisitions are made at different times in the same geometric configuration, then InSAR can be used to measure radial velocity of targets and to assess displacements caused by, e.g., volcanoes and earthquakes.
Explain the principles of synthetic aperture radar (SAR) interferometry
Apply InSAR technique
Discuss advantages and disadvantages of across- and along-track interferometry
Completed