Satellite imagery can be used for the identification of archaeological sites and to inform heritage management. However, in England where aerial photography is readily available, the limitations of cost and resolution mean that satellite imagery is rarely used. The related technology of multi-spectral data captured from airborne systems has shown considerable potential. English Heritage continues to monitor developments and support research in this area.
Resolution is the key
There are a number of satellites currently in operation which operate at a resolution that may be suitable for archaeological research. These include IKONOS, Quickbird, WorldView, GeoEye. Online tools such as GoogleEarth and Bing Maps are providing imagery to a wider audience, but it is worth noting that the most detailed views available on these systems are actually derived from aerial photographs. Whilst English Heritage continues to use aerial photography as a major source of information rather than satellite sourced material, we are involved within wider partnerships in order to monitor developments including the Forum for Earth Observation Applications and GMES.
Multi-spectral data
One particularly useful factor that satellite imagery has over conventional photography is that most provide multi-spectral data, covering at least the near infra red (NIR) and several other wavelengths rather than being confined to the standard visible spectrum. By manipulating the different wavelengths it is possible to reveal features not easily discernible on conventional photography. This is particularly valuable for environmental monitoring, but also has some potential for archaeological survey.
Multi-spectral data can also be captured from airborne platforms, and the higher resolution data available from systems such as CASI is more useful for archaeological purposes than satellite sourced data.
