While archaeology is still a hands-on type of profession, because all archaeology projects need ground work to verify any findings, the use of remote sensing techniques and methodology has become an important addition to the technical tools available to us.
Using space technology often conjures up images of aliens and UFOs, but instead of looking to the skies, archaeologists are able to look beneath the existing landscape of our planet using infrared light, capable of penetrating areas of interest in the Earth as much as a meter or so in depth.
This so-called space archaeology is actually satellite archaeology, and it’s a non-invasive way of mapping and monitoring potential sites of interest to researchers. But the exciting thing about this new use for space technology is what it can tell us about the Earth’s past, in addition to past civilisations.
Sarah Parcak — pioneer in the field of space archaeology
Sarah Parcak is a National Geographic Fellow and a Professor of Anthropology at the University of Alabama at Birmingham (UAB). She was interviewed by the CBC recently and has only good things to say about the use of satellite technology in archaeology. Besides carrying the usual tools of the trade when on a promising archaeology site, she also carries a slew of satellite images.
With the help of satellite imagery, she has located 17 potential pyramid sites in Egypt. She’s also identified 3,100 little-known settlements and about 1,000 lost tombs She has made major discoveries throughout the Roman Empire and the Viking world, according to her website, GlobalXplorer.
Digital Journal has followed many of her discoveries, especially the discovery of the Viking settlements in Newfoundland recently. It was Parcak who first used satellite imagery in Egyptology, and since then, she has used the technology in finding sites around the world.
Archaeological remote sensing
Humans are restricted to what they can see in visible light only. The light spectrum is much more than just visible light, and that’s where satellite imagery is so valuable to us. Our ability to build detectors that can see what is invisible to us and computers that can bring that invisible information to our eyes is amazing.
We can call remote sensing a discovery technique. We can program a computer to look for specific “signatures,” and these signatures will serve as recognition points or “fingerprints.” This way, soil depth, water courses, elevation, transportation routes or even city walls can be distinguished.
And this remote sensing technology is actually broader than you might think because we can see its applications in other fields of study besides archaeology, including climatology, forestry, botany, hydrology and many others. The ability of satellite imaging technology that uses the full range of the light spectrum also means that environmental factors have to be taken into consideration.
Landscape features such as soil, vegetation, geology, and man-made structures of possible cultural interest have specific signatures that multispectral satellites can help to identify. But you have to know the ecology and geology of the area you are studying in order to interpret the data sent back by the satellites.
NASA archaeologist Tom Sever is a pioneer in using remote-sensing technology in studying the Mayan Empire. He has used this technology in mapping roads and causeways invisible to the naked eye, and in uncovering settlement patterns, population densities, societal structure, communication and transportation in the ancient empire and its growth and collapse.
Some interesting space archaeology sites
The image of Angkor, Cambodia was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on the 15th orbit of the space shuttle Endeavour on September 30, 1994. The body of water in the south-southwest corner is Tonle Sap, Cambodia’s great central lake.
The urban area at the lower left of the image is the present-day town of Siem Reap. The adjoining lines are both modern and ancient roads and the remains of Angkor’s vast canal system that was used for both irrigation and transportation. The large black rectangles are ancient reservoirs. Today the Angkor complex is hidden beneath a dense rainforest canopy.
This image of Giza was taken on April 19, 1994, by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and the United States space agencies, is part of NASA’s Mission to Planet Earth.
The image shows an area west of the Nile River near Cairo, Egypt. The dark band along the right side is the Nile River and you can clearly see the difference in population density between urban areas and the desert by the difference in the bright and dark areas in the center of the image. The boundary of the extent of the Nile flooding also helps to determine where ancient Egyptians lived.
