Aggregation

Aggregation is the process of combining classes in order to create a new aggregate class. A maximum of 255 classes can be reassigned in a single session. Aggregation is often performed on the results of an unsupervised classification. A common approach in unsupervised classification is to generate as many cluster classes as possible. With the benefit of reference data or first-hand knowledge of the scene, the analyst aggregates the spectral clusters into meaningful thematic classes.