Nikolaos Galiatsatos

Late Chalcolithic and Early Bronze Age Landscapes of Settlement and Mobility in the Middle Euphrates: A Reassessment

Abstract Urbanization occupies an ambiguous position in the development of the Middle Euphrates region of Turkey and Syria, in part because the area frequently formed a contested region between other stronger Early Bronze Age polities. This paper aims to review evidence from a series of archaeological surveys to illustrate trends in settlement during the 4th and 3rd millennium BC. Re-analysis of survey data from three exemplar regions in the Middle Euphrates demonstrates that by including settlement away from the main Euphrates Valley we get a picture of two main zones of settlement corresponding to agro-ecological zones. In the northern zone, settlements underwent phases of nucleation and dispersal through time, but long-term configurations were relatively stable. In contrast, a southern zone, south of the Sajur Valley, was characterized by rapid colonization and some degree of boom and bust growth of towns, perhaps encouraged by the opportunities afforded by the high risk but high rewards of the ‘zone of uncertainty’. Although ecological conditions and climate change played a role in settlement growth and failure, in part by setting the parameters for agro-pastoral production, it is evident that socio-political circumstances, chronic conflict and sheer opportunism were probably key to both the growth and decline of the southern settlements.

Radiometric Normalisation of Multisensor/Multitemporal Satellite Images with Quality Control for Forest Change Detection

This paper aims to investigate the applicability of a relative radiometric normalisation method to a set of multitemporal images acquired by sensors of substantially different characteristics. The overall aim of the project is to assess the potential of satellite remote sensing for identifying forest land cover change in Scotland. In this study, the Pseudo-Invariant Features (PIFs) concept was investigated. PIFs are landscape elements (pixels) whose reflectance values are nearly constant over time. We use the Principal Components Analysis (PCA) to identify the PIFs, because of the simplicity of the approach and the accuracy of the results. The approach also needs less image interpretation, thus it saves time and offers objectivity in the selection of PIFs. The radiometric normalisation method of PIFs is applied on Landsat TM (1989 & 1994) and ETM+ (2000), IKONOS (2003) and DMC (Disaster Management Constellation) (2005) multitemporal images. The particular sensors are very diverse in spatial, spectral and radiometric information content. The images were radiance corrected and then orthorectified. Different orthorectification methods were used but the overall accuracy remained within change detection limits (plusmn0.5 pixels). The quality control of the radiometric normalisation is done spatially, spectrally and statistically. Issues about the use of PCA for identifying PIFs are discussed. The results show that the relative radiometric normalisation using PCA to select PIFs can perform very well in a multisensor/ multitemporal application when care is taken in the pre-processing stages.

New Microslice Technology for Hyperspectral Imaging

We present the results of a project to develop a proof of concept for a novel hyperspectral imager based on the use of advanced micro-optics technology. The technology gives considerably more spatial elements than a classic pushbroom which translates into far more light being integrated per unit of time. This permits us to observe at higher spatial and/or spectral resolution, darker targets and under lower illumination, as in the early morning. Observations of faint glow at night should also be possible but need further studies. A full instrument for laboratory demonstration and field tests has now been built and tested. It has about 10,000 spatial elements and spectra 150 pixel long. It is made of a set of cylindrical fore-optics followed by a new innovative optical system called a microslice Integral Field Unit (IFU) which is itself followed by a standard spectrograph. The fore-optics plus microslice IFU split the field into a large number of small slit-like images that are dispersed in the spectrograph. Our goal is to build instruments with at least hundreds of thousands of spatial elements.

High Resolution Elevation Data Derived from Stereoscopic CORONA Imagery with Minimal Ground Control

The first space mission to provide stereoscopic imagery of the Earth’s surface was from the American CORONA spy satellite program from which it is possible to generate Digital Elevation Models (DEMs). CORONA imagery and derived DEMs are of most value in areas where conventional topographic maps are of poor quality, but the problem has been that until recently, it was difficult to assess their accuracy. This paper presents a methodology to create a high quality DEM from CORONA imagery using horizontal ground control derived from Ikonos space imagery and vertical ground control from map-based contour lines. Such DEMs can be produced without the need for field-based ground control measurements which is an advantage in many parts of world where ground surveying is difficult. Knowledge of CORONA image distortions, satellite geometry, ground resolution, and film scanning are important factors that can affect the DEM extraction process. A study area in Syria is used to demonstrate the method, and Shuttle Radar Topography Mission (SRTM) data is used to perform quantitative and qualitative accuracy assessment of the automatically extracted DEM. The SRTM data has enormous importance for validating the quality of CORONA DEMs, and so, unlocking the potential of a largely untapped part of the archive. We conclude that CORONA data can produce unbiased, high-resolution DEM data which may be valuable for researchers working in countries where topographic data is difficult to obtain.