Change detection using spatial data problems and challenges

This article describes the SYKE´s approach to change detection using high and medium resolution satellite images and present experiences concerning change detection. If it is possible, information about the land use is acquired using digital map data. The main problems with satellite images have been the availability of cloud-free Landsat images and atmospheric correction of images. The lack of historical ground truth information makes the classification of old images and the validation of result difficult. The size of reliably detectable change in the case of forest clear cuts seems to be 5 pixels. The most important characteristics of map data are metadata and accuracy assessment.