Taking a Closer Look at InSAR

As existing dams, levees, and other civil works structures continue to age, and new structures are being built on sites that are less than optimal, the importance of instrumentation and monitoring to understand performance and risk continues to increase. Many monitoring programs include surface deformation monitoring, such as conventionally surveyed alignment and settlement monuments. But technological advances in geodetic measurements in recent years now permit collection of large volumes of surface monitoring data with high frequency and high accuracy through tools like global positioning system and global navigation satellite system receivers, laser identification detection and ranging, and photogrammetry and electronic distance measurement devices, such as automated total stations.