Subscribe to our newsletter. Ask an Expert Orthophotos and GIS Aerial photographs play an important role in GIS data acquisition and visualization. First, they help provide a solid visual effect.
Many people are more able to put spatial concepts into perspective when seeing photos.
In addition, the secondary and perhaps more vital role is to provide a basis for gathering spatial information. Examples of this are features such as roads, vegetation, water features. Before this information can be gathered in a way that is useful for a GIS system, the aerial photographs must be prepared in a way that removes distortion from the image. This process is called orthorectification. Without this process you wouldn't be able to do such functions as make direct measurements of distances, angles, positions, and areas.