Monumental architecture is a prime indicator of social complexity, because it requires many people to build a conspicuous structure commemorating shared beliefs. Examining monumentality in different environmental and economic settings can reveal diverse reasons for people to form larger social units and express unity through architectural display. In multiple areas of Africa, monumentality developed as mobile herders created large cemeteries and practiced other forms of commemoration. The motives for such behavior in sparsely populated, unpredictable landscapes may differ from well-studied cases of monumentality in predictable environments with sedentary populations. Here we report excavations and ground-penetrating radar surveys at the earliest and most massive monumental site in eastern Africa. Lothagam North Pillar Site was a communal cemetery near Lake Turkana (northwest Kenya) constructed 5,000 years ago by eastern Africa's earliest pastoralists. Inside a platform ringed by boulders, a 119.5-m mortuary cavity accommodated an estimated minimum of 580 individuals. People of diverse ages and both sexes were buried, and ornaments accompanied most individuals. There is no evidence for social stratification. The uncertainties of living on a "moving frontier" of early herding-exacerbated by dramatic environmental shifts-may have spurred people to strengthen social networks that could provide information and assistance. Lothagam North Pillar Site would have served as both an arena for interaction and a tangible reminder of shared identity.

Since the 1970s, archaeologists have known that thermal infrared images have the potential to reveal archaeological features ranging from buried architecture to concentrations of surface artifacts and cultural landscape elements such as roads, fields, or earthworks. Despite a long history of experimental research in archaeological aerial thermal imaging (e.g., Bellerby et al. 1990; Buck et al. 2003; Giardino ABSTRACTWhile a long history of experimental data shows that aerial thermal images can reveal a wide range of both surface and subsurface archaeological features, technological hurdles have largely prevented more widespread use of this promising prospecting method. However, recent advances in the sophistication of thermal cameras, the reliability of commercial drones, and the growing power of photogrammetric software packages are revolutionizing archaeologists' ability to collect, process, and analyze aerial thermal imagery. This paper provides an overview of the theory behind aerial thermography in archaeology, as well as a discussion of an emerging set of methods developed by the authors for undertaking successful surveys. Summarizing investigations at archaeological sites in North America, the Mediterranean, and the Near East, our results illustrate some contexts in which aerial thermography is very effective, as well as cases in which ground cover, soil composition, or the depth and character of archaeological features present challenges. In addition, we highlight novel approaches for filtering out noise caused by vegetation, as well as methods for improving feature visibility using radiometric thermal imagery.Si bien una larga historia de datos experimentales muestra que las imágenes térmicas aéreas pueden ser utilizadas para detectar una amplia gama de rasgos arqueológicos tanto superficiales como subsuperficiales, los obstáculos tecnológicos han en gran parte impedido la adopción generalizada de este prometedor método de prospección. Sin embargo, los recientes avances en la sofisticación de las cámaras térmicas, la fiabilidad de los drones comerciales y el creciente poder de los paquetes de software fotogramétricos han puesto al alcance de los arqueólogos la capacidad de recopilar, procesar y analizar imágenes térmicas aéreas. Este artículo ofrece una visión general de la teoría detrás de la aplicación de la termografía aérea en la arqueología, así como una discusión de un conjunto emergente de métodos desarrollados por los autores para llevar a cabo prospecciones remotas. Se resumen las investigaciones realizadas en sitios arqueológicos de Norteamérica, el Mediterráneo y el Cercano Oriente, cuyos resultados ilustran casos en los que la termografía aérea es muy eficaz, así como contextos en los que la cubierta vegetal, la composición del suelo o la profundidad y características específicas de los rasgos arqueológicos presentan desafíos. Destacamos nuevos avances para filtrar el "ruido" causado por la vegetación y métodos para mejorar la visibilidad de los rasgos arqueológicos utilizando imágenes térmi...

While archaeologists have long understood that thermal and multi-spectral imagery can potentially reveal a wide range of ancient cultural landscape features, only recently have advances in drone and sensor technology enabled us to collect these data at sufficiently high spatial and temporal resolution for archaeological field settings. This paper presents results of a study at the Enfield Shaker Village, New Hampshire (USA), in which we collect a time-series of multi-spectral visible light, near-infrared (NIR), and thermal imagery in order to better understand the optimal contexts and environmental conditions for various sensors. We present new methods to remove noise from imagery and to combine multiple raster datasets in order to improve archaeological feature visibility. Analysis compares results of aerial imaging with ground-penetrating radar and magnetic gradiometry surveys, illustrating the complementary nature of these distinct remote sensing methods. Results demonstrate the value of high-resolution thermal and NIR imagery, as well as of multi-temporal image analysis, for the detection of archaeological features on and below the ground surface, offering an improved set of methods for the integration of these emerging technologies into archaeological field investigations.

No abstract