Prior to image classification, collection of training sites and obtaining a signature file is the most critical step. Field visits with a reliable GPS Unit is usually the first step followed by overlaying the points on the to-be-classified image. Other than this when identifying training sites on satellite images, especially the coarse resolution ones what are the rules normally followed by professionals – like minimum number of pixels in a training site, distance between two training sites for same/different classes, how improvements are made after preliminary classification etc. Standard references are also welcome.
[GIS] Identifying training sites
classificationimagery
Best Answer
I wont be able to give a great deal of information on this, but there are certain rules I think we need to follow for training sites: