Visible light represents only one range of wavelengths within the electromagnetic spectrum. The archaeological potential of other wavelengths, such as in the near infrared or thermal ranges, is still undergoing assessment, but it has already been demonstrated that such hyperspectral scanning has the potential to address some of the biases in aerial data recovery referred to above. Variations in ground surface texture, vegetation cover, or moisture content have different spectral signatures which can be recorded by a scanning electron spectrometer and may produce patterns facilitating the identification of potential buried archaeological features.
Light detection and ranging (LIDAR), which involves analyzing the reflections back to the aircraft of a scanning pulse laser, provides a means of recording variations in surface elevation in considerable detail. This uses the same identification principle as that for shadow sites, but provides the opportunity to exaggerate the height differential or change the light direction, or angle of view in order to maximize the visibility of archaeological sites which are barely extant.
Finally, with the recent great improvements in resolution and ease of access, the potential of satellite imagery for archaeological aerial reconnaissance has increased considerably.
See also: Europe, West: Historical Archaeology in Britain; Remote Sensing Approaches: Geophysical; Seasonality of Site Occupation; Sites: Catchment Analysis; Formation Processes; Mapping Methods; Soils and Archaeology.
World History
