What does georeferencing or rectification mean?
Rectification or georeferencing is the process of assigning real-world coordinates (projection and datum) to geographic data to tie it to the Earth. When data are collected by cameras or digital sensors, they have inherent forms of distortion from the sensor and terrain. These various forms of distortion must be removed before images will spatially match other geographically referenced data sets. Once the distortion is removed and real-world coordinates are assigned, the data should accurately represent a given portion of the Earth, allowing for analysis with other properly referenced themes, layers, and images.
