The Science behind Archaeological Signatures from Space

Abstract

Archaeology has traditionally focused on studying historic or prehistoric people and their cultures by analysis of their artefacts, inscriptions, monuments and other such material remains, especially those that have been documented from excavations. This focus is somewhat narrow, because it excludes many new methods that have emerged in the last few decades (described in detail by Prabhakar and Korisettar in this special section (page 1873)). One such novel method is to study large imprints on the landscape caused by human activity. These tell-tale features include soil marks, crop marks, drainage patterns, field boundaries and a host of man-made structures, whose study can provide additional cultural insights. In some cases, these features are difficult to detect by the naked eye at ground level, but are detectable by remote sensing techniques from aerial/space-based platforms in a non-destructive manner. For these reasons, it is now well recognized that examining archaeological landscapes using remote sensing can complement traditional investigations. An analysis of remote sensing data can play an important role in (1) understanding spatial relationships between cultural materials and activities, (2) formulating archaeological sampling schemes, (3) measuring distances and spatial distributions of structures and monuments, and (4) evolving schemes for their conservation.

Satellite Remote Sensing for the Analysis of the Micia and Germisara Archaeological Sites

“…The concept underlying the second objective evolved from the wide recognition of satellite remote sensing as a non-destructive tool for uncovering archaeological landscapes [129]. Some archaeological features are buried over the years leaving some traces above ground with a specific shape, size and pattern [130]. The methods proposed in this paper can be applied for the assessment of different heritage sites.…”

“…An ancient underground structure like a wall or a road influences the soil structure [11,146,147]. The presence of underground structures restricts the evolution of the plants in the soil by preventing the roots from developing normally [130]. The lack of nutrients and water compared to the surrounding areas further stresses plants.…”

“…In this paper, a false colour composite was created using the NIR, Red and Green spectral bands of the Sentinel-2 image (Figure 20), each as input for the Red, Green and Blue channels, respectively. The natural colour composite created using the Red, Green and Blue bands of the visible spectrum does not offer relevant and fine information for the archaeological sites [130]. Vegetation reflects in the NIR band and absorb in the Red band, hence providing useful information about vegetation in what regards its presence or absence as well as growth and health status.…”

“…For example, certain false color composite images enable the effortless identification of areas covered by vegetation.In this paper, a false colour composite was created using the NIR, Red and Green spectral bands of the Sentinel-2 image (Figure20), each as input for the Red, Green and Blue channels, respectively. The natural colour composite created using the Red, Green and Blue bands of the visible spectrum does not offer relevant and fine information for the archaeological sites[130].…”