Sub-pixel artifact detection using remote sensing

The sub-pixel spectral detectability of obsidian and ceramic artifacts against typical soil backgrounds from two study areas in the western USA was analytically evaluated to determine the usefulness of remote sensing as a tool for artifact detection [in the visible (VIS), near-infrared (NIR), and/or thennal-infrared (TIR) portion of the spectrum]. In the VIS/NIR, surface concentrations of pottery needed to be 85% or greater to be detected against backgrounds of soil, rock, and vegetation. At the same wavelengths, obsidian is spectrally similar to shade and cannot be uniquely detected unless the effects of shade are independently removed. In cases where shade is not a major factor, obsidian at concentrations of 2-3% can be detected. In the TIR, pottery thresholds ranged from 12 to 48%, depending on the composition of the background. Obsidian detection thresholds ranged from 4 to 25% cover. These results indicate that surface mapping using remote sensing in the TIR has the potential to be an effective tool for prioritizing large areas for future ground surveys. (C) 2003 Elsevier Science Ltd. All rights reserved.