Effects of image characteristics on the identification and extraction of archaeological features from Ikonos-2 and Quickbird-2 imagery: case study Sagalassos (southwest Turkey)

Abstract

This paper compares and evaluates the significance of spectral characteristics and pixel resolution of the very high spatial resolution satellite systems (VHSRS) Quickbird-2 and Ikonos-2 for automatic extraction of ancient features on one archaeological site, the antique town Sagalassos (southwest-Turkey). The evaluation of the spectral characteristics is based on a band-by-band comparison. Pixel- and object-based classification techniques are compared with visual analyses to assess the effects of different image characteristics.

The analysis reveals that Quickbird-2 is outperforming Ikonos-2 for the visual identification of ancient remains. Its augmented spatial resolution however does not necessarily result in a better automatic classification. For Sagalassos, maximum likelihood classification on Ikonos-2 gives the best results. The accuracy of automatic extraction depends on the type and characteristics of the VHSRS data, the classification method and on on-site parameters. Site characteristics appear to play a limited role in object-based extraction on Quickbird-2, but become very important on Ikonos-2.

Acknowledgements

We thank the Belgian Science Policy Office for providing us with the VHSR Ikonos-2 image for the antique site of Sagalassos. We are also grateful to the entire archaeological team of the Sagalassos project for providing sufficient archaeological information in order to carry out this research. This study is supported by the Belgian Programme on Interuniversity Poles of Attraction, initiated by the Belgian State, Prime Ministers Office, Science Policy Programming (IUAP P5/09).