A UAV-based approach for a cost-efficient documentation of agrarian structures in the arid Atacama area (N. Chile)

SAA 80th Annual Meeting

San Francisco. Estados Unidos
Congreso. 2015

The paper summarizes the contribution of UAV to the documentation of a vast group of late Prehispanic agrarian elements (fields, irrigation canals) in the arid Atacama area (northern Chile). Taking advantage of the extraordinary preservation and visibility of fields, canals and other constructions, the general mapping of the area was based on a combination of visual interpretation of high resolution satellite images (GeoEye 1) and fieldwork.

However, despite their high resolution, satellite images did not provide sufficient detail of some areas. A more detailed approach was needed to produce an adequate documentation of fields, settlement areas and singular constructions. An SFM-based photogrammetry approach was carried out, based on a low cost UAV (Dji Phantom) and a consumer-grade compact digital camera for the acquisition of low altitude aerial images that allowed the generation of 3D models and orthoimages of some areas. Finally, ground based photogrammetry was also used to capture and represent some elements in greater detail.

The main result has been the construction of a highly detailed and accurate map of a complex group of archaeological structures, which has been used since for the analysis and interpretation of the area, and also for the design of new fieldwork seasons.