Abstract

Following the suggestion made by Johnson (Johnson B.A., 2015), a polygon-based cross validation (CV) method is compared to the pixel-based CV method to classify different levels of land cover categories using a single-date Landsat 8 image and time series of Landsat TM images. Also, different variants of band combinations, with and without the thermal bands, were considered. The results demonstrate that the inclusion of thermal information into the classification process will improve the classification performance, as was already shown in our original study (Sun and Schulz, 2015). However, it is also demonstrated that the polygon-based CV method produced lower overall accuracy values when compared to the pixel-based CV method. This confirms the argument made by Johnson that a correlation of calibration and validation data due to random sampling of multi-scale data will overestimate the performance of the classifier, and independent polygon-based CV methods have to be applied instead. View Full-Text