Unsupervised classification is useful when there is no preexisting field data or detailed aerial photographs for the image area, and the user cannot accurately specify training areas of known cover type.

What is unsupervised classification used for?

Unsupervised classification using cluster algorithms is often used when there are no field observations, such as GGRS, till geochemistry, and other reliable geologic information.

Which is better supervised or unsupervised classification?

While supervised learning models tend to be more accurate than unsupervised learning models, they require upfront human intervention to label the data appropriately. For example, a supervised learning model can predict how long your commute will be based on the time of day, weather conditions and so on.