Low-Cost UAV Photogrammetry: An Application for Archaeological Survey in The Upper Gila River Watershed, New Mexico

Abstract

Use of low-cost unmanned aerial vehicles (UAV) for documenting archaeological sites with close-range photogrammetry (CRP) and creation of 3D-models is an increasingly popular option for archaeologists looking to supplement or replace traditional mapping techniques. As this combined suite of technologies moves into mainstream use, the need to test the quality of the data, the accuracy and precision of site models becomes increasingly important. In this study, I assess the use of UAV CRP for its capabilities to capture the surface expression of Pueblo period archaeological sites in the Upper Gila River Watershed of southwest New Mexico. Five sites containing low relief archaeological features such as masonry rubble mounds, pit depressions, rock alignments, or signs of disturbance are documented with 3D-modeling and digital elevation models (DEM). I use a 3D-model of a built environment (a concrete skateboard park) with known dimensions as a basis of comparison to test the georeferenced accuracy and measurement precision of five archaeological site models. This thesis describes the methods used for the collection and post-processing of image data and an evaluation of the resulting site models. The results are assessed for their successes and failures to achieve a proper evaluation of 3D-model precision and accuracy.