Pedestrian archaeological surveys required to locate archeological sites and artifacts are time consuming and expensive, with costs estimated at about $35 per acre. Scientists in a number of disciplines have been successful in identifying minerals and plant species using remote sensing technologies. This same approach has not been tried for archaeological data collection, although there is no compelling theoretical reason why it would not be successful.

This one-year pilot study will explore improved identification and assessment methods at prehistoric, historic, and traditional cultural sites on Department of Defense and Department of Energy lands. The proposed study will explore the possibility of utilizing remote sensing technologies in archaeological data collection by examining whether certain kinds of archaeological materials may be detected using current remote sensing technologies.

To determine if selected artifacts can be remotely detected involves measuring the spectra of a variety of artifacts under both field and laboratory conditions. This data then will be put into a “detection limits” model to predict the amount of material that is theoretically detectable using any given remote sensing device. The two target materials involved in this study, ceramic pot sherds and obsidian tools, were chosen because of the abundance of these materials on archaeological sites in the semi-arid West and the potential for these two materials to demonstrate unique spectral signatures. Los Alamos National Laboratory in New Mexico has been selected as a study site because of the tremendous amounts of ceramic sherds found there. The China Lake Naval Air Weapons Station in California has been selected as a second study site because of its large obsidian quarries. Two thermal infrared instruments (TIR) and one visible/near infrared instrument will be used to collect field data of representative background and target materials from the study sites. A portable Advanced Spectral Devices field spectrometer will be used to collect data from the same study areas which then will be scanned using the TIR instruments. Mathematical procedures developed at the University of Washington Geological Sciences Remote Sensing Laboratory will be used for determining the threshold detection limits of the target materials.

Field studies have been completed at study plots at Los Alamos National Laboratory and China Lake Naval Air Weapons Station. Using a spectral detectability model based on laboratory and field spectra, the following have been concluded: (1) in the visible/near-infrared portion of the spectrum, pottery mimics mixtures of shade and substrates (rocks and soils), making it undetectable (Obsidian mimics shade and, therefore, can be detected only if the effects due to shading are removed through topographic modeling where vegetation is scarce.) and (2) in the thermal infrared portion of the spectrum, obsidian is very detectable at low percent coverage of the surface (~5 percent). Pottery may be detectable in the thermal spectrum, but only at high percent surface coverage (~<20 percent) and under minimal vegetation cover.

This study will determine two things. The first is whether ceramic and obsidian artifacts have unique spectral characteristics. The second is at what concentrations on the ground surface these materials might be detectable, given current remote sensing instrumentation.