The effect of pixel resolution and spectral characteristics on the extraction of archaeological features from very high-resolution remote sensing imagery: Sagalassos, southwest Turkey

摘要

The launch of several very high spatial resolution satellite (VHSRS) systems (Ikonos-2, Quickbird-2 and others) in the recent past also has provided new possibilities for archaeological research. The emphasis of this paper is to compare and evaluate the contribution of spectral characteristics and pixel resolution of Quickbird-2 and Ikonos-2 for automatic extraction of ancient features from VHSRS imagery. The spectral characteristics of both images have been evaluated by a band-by-band comparison. Apart from a visual comparison, pixel- and object-based classification techniques are applied to assess the effect of different image characteristics. The study is carried out on the antique site of Sagalassos (southwest Turkey). A profound analysis of the VHSRS data reveals that the spectral characteristics of Ikonos-2 capture a more detailed spectral reflectance for the same ground target compared to Quickbird-2. The latter outperforms Ikonos-2 for the visual identification of ancient remains due to its enhanced ground resolution. The application of automatic extraction techniques on archaeological remains in the ancient town of Sagalassos shows opposing results. Compared with the visual interpretation of Quickbird-2, the pixel-based technique gives the best results for Ikonos-2, while an object-based method is best for Quickbird-2.