| This research investigates the potential of historic aerial photographs as a tool for archaeological site prospecting. Craighead and Mississippi Counties in northeast Arkansas and areas adjacent to the Red and Little Rivers in southwest Arkansas were chosen as study areas. These regions have undergone significant changes in the past few decades and were expected to yield visible types of archaeological sites. Historic aerial images of these areas were obtained through the U.S. Geological Survey’s EarthExplorer database ( http://earthexplorer.usgs.gov/). These images were processed using Agisoft PhotoScan Professional to produce extensive regional orthoimages.;Using the Arkansas Archeological Survey’s Automated Management of Archeological Site Data in Arkansas (AMASDA) database, known archaeological sites dating later than Late Woodland were compared against PhotoScan-generated orthoimagery to see if they were visible using a tripartite classification scheme: site invisible, site possibly visible, and site visible. Trends in site visibility were assessed in terms of the photographs’ characteristics (e.g., dates, geographic scales, download resolutions) and the nature of the archaeological sites (e.g., surface scatters, mound sites, middens, standing structures).;For specific archaeological sites, possible archaeological, modern, and natural features were digitized. Within-site visibility was reexamined with respect to the sites’ temporal ranges, previously documented structures and features, seasonal differences of the imagery, and disturbances from modern land-use. Historic digital elevation models (DEMs) were generated in PhotoScan to assess the performance of the software’s geometry-building algorithm for intrasite prospecting.;Overall, only a small percentage of specific site types (i.e., mounds, historic structures, middens) were classified as definitively visible. However, the site classification scheme used in this study provides a subset of sites with potential archaeological anomalies, which can be investigated more closely with site survey reports. High-resolution orthoimages and DEMs produced from stereopairs in PhotoScan also present archaeologically promising anomalies for subsequent analyses. |
