Accuracy assessment of satellite derived land-cover data: A review

Accuracy assessment of land-cover classifications derived from remote sensing data has been recognized as a valuable tool in judging the fitness of these data for a particular application. Recent research initiatives in the area of spatial data accuracy and integration of remote sensing data in geographic information systems have revived the discussion on accuracy assessment. This article aims at contributing to this discussion by means of a review based on a division into positional and thematic accuracy. An important observation is that there are a limited number of methods for assessing data accuracy. However, the applied definitions differ very much from author to author, especially in the assessment of thermatic accuracy. Accuracy assessment mostly yields one single measure such as root-mean-square error or proportion of pixels correctly classified. These single measures do not give sufficient information and they can be based on statistically or methodologically non-valid methods. Therefore, not a single measure but also the total process of assessing these measures should explicitly be reported.