Role of LiDAR in archaeology

PNAS u August 7, 2012 u vol. 109 u no. 32 u 12837–12838 www.pnas.org/cgi/doi/10.1073/iti3212109 Radiocarbon dating enables archaeologists to probe relationships between ancient sites, peoples, and cultures, allowing them to determine the absolute dates and ages of past events and settlements. Arlen Chase et al. (pp. 12916– 12921) report that a widely used laser-based remote sensing tool known as light detection and ranging, or LiDAR, has similarly transformed archaeology by allowing an improved interpretation of the scale and organization of ancient landscapes. The authors report that the use of LiDAR in densely forested areas in Mesoamerica—including Belize and Mexico—has enabled archaeologists to study landscapes and ruins at previously elusive spatial resolutions. The detailed spatial information, including roadways, caves, burial chambers, low-lying constructions, outlying nodes, and agricultural terracing, revealed that some ancient Mesoamerican sites are larger and more complex than previously suggested by sociopolitical modeling studies. Because the remote sensing tool can cut through canopies to visualize the underlying topography through large volumes of 3D measurements collectively called point cloud data, it has helped answer longstanding questions such as those concerning the ancient population sizes and state structures of the Maya and the importance of the state of Tarascans in central Mexican developments. According to the authors, LiDAR is an invaluable complement to on-the-ground investigations and has enriched the field of archaeology. — P.N. Role of LiDAR in archaeology