The document discusses the importance of measuring change using RADAR imagery. It provides examples of how RADAR has been used to monitor natural disasters like tornadoes, earthquakes, floods, and oil spills. RADAR data is well-suited for change measurement because it can see through clouds and darkness and man-made structures provide strong reflections. Interferometric processing of RADAR data pairs enables coherence change detection and displacement mapping with centimeter accuracy, allowing monitoring of subsidence from activities like resource extraction. The document also describes how ERDAS Imagine software and its radar tools were used by Kongsberg Satellite Services to develop an oil spill and vessel detection system from satellite imagery within 30 minutes of acquisition.