Remote Sensing/Satellite Imaging
John C. Sanders, Head
Oriental Institute Computer Laboratory
The use of aerial photographs and ground-based instrumentation is an early form of remote sensing analysis. The archaeological explorations and publication of Erich Schmidt's Flights over Ancient Cities of Iran (Schmidt 1940) was a pioneering project in the technique, followed shortly by the large scale settlement surveys in central and southern Mesopotamia by Robert McC. Adams (Adams 1957, 1958, 1965, 1972a, 1972b, 1981; Adams and Nissen 1972), and more recently by the field reconnaissance work of the Oriental Institute's Nippur Expedition (Gibson 1972, 1977).
Remote sensing in the form of satellite image analysis is the most important new data acquisition modality for archaeological research. This technology provides an entirely new primary data source by detecting and recording objects or phenomena from a distance through devices that are sensitive to various bands of the electromagnetic spectrum. The rapid advancements in remote sensing now promise to provide reliable and inexpensive information that can be employed for intensive archaeological and ethnographic investigations. Improved satellite-based remote sensing instruments with greater resolution (down to 10 meters) and more precise bandwidths are now opening the way to new frontiers in archaeological investigations, environmental, and ecological data analysis. Excellent overviews of the various archaeological applications of remote sensing/satellite imaging are in Ebert 1984; Sever and Wiseman 1984; and Limp et al. 1988.
Satellite remote sensing is particularly important because it can provide enormous amounts of environmental data covering very large areas in a cost-effective manner. Satellite imagery is generally less expensive and more universally available than comparable aerial photographic coverage, and it comes in a digital format for immediate importation into computer database systems, such as GIS. Dozens of archaeological projects have used satellite imagery to study prehistoric and historic land use in a variety of different environments around the world, including Mesoamerica, the United States, and Europe (Limp et al. 1988). A recent example for ancient Near Eastern studies involves the discovery of the city of Ubar, in southern Oman, by a team of researchers from the Jet Propulsion Laboratory (JPL) and the California Institute of Technology (Williams 1992).
Most archaeological projects use remote sensing/satellite imaging data for two purposes:
- (1) to obtain environmental land use and land cover information (Ebert 1978).
- (2) to attempt correlating site "signatures" with spectral data recorded by remote scanners (Madry 1987; Farley et al 1988).
Remote sensing/satellite image analysis is also important to archaeological research because most archaeologists can no longer excavate all the extant remains of an ancient site. This fact only serves to demonstrate the need for new methods of data acquisition and processing. The addition of remote sensing/satellite imaging to the arsenal of tools available for archaeological research will help to offset the ever smaller excavation exposures from which primary data is retrieved.