Change is inevitable. Harnessing that change has advantages, especially with tools that can detect and anticipate it. At the National Geospatial-Intelligence Agency, change detection plays an important role in helping analysts carry out the agency’s various missions. Change detection is used at NGA to support military customers, but it is also a useful tool for farmers, foresters and government agencies. It can also help predict natural disasters such landslides before they occur.
From a geography standpoint, change takes place on the planet’s surface as a result of climate, geological events and human-made activities. Observing that change and comparing the before and after to easily reach an analytic assessment or accurate prediction has long been a goal of scientists, government agencies, the military and industry.
Change detection, from a foundation GEOINT perspective, is the process of measuring the attributes of particular geographic areas that have altered between two or more time periods. It is the comparison of multiple images collected for one area at different times, to determine the type, magnitude and location of change. The analysis is derived from either aerial or satellite imagery.