Cuchirrumi1 Sunken Plaza by Nathan Craig

Canon Powershot S90 KAP

This orthophoto KAP panorama shows an archaeological site I originally spotted on an image from 2004 that was displayed in Google Earth. The site consists of a small Preceramic mound with a sunken circular court. The mound and court are interesting both for their small size and for the unusual configuration. At this site, the sunken court appears to come off one of the corner of the mound, rather than from one of the sides. In 2010, when I visited the location to see the site, it was severely damaged by a bulldozer. To document the damage, I photographed the site by means of kite aerial photography. In the image, one can clearly see the dozer scrapes that gouged into a corner of the mound and part of the sunken plaza.

The procedures for mapping the site are as follows. Photographic targets were placed inside the area of interest. These targets where mapped with a high accuracy (10cm) GPS. Then the area of interest was imaged by kite aerial photography. These photographs were then processed with AgiSoft PhotoScan, a structure from motion photogrammetry package. This produced a dense 3D model. To make the orthophoto mosaic, the individual photographs are projected back onto the model and written to a flat file. The image was exported as a series of tiles. These tiles were then assembled in Photoshop and saved as a RAW file. That file was uploaded to the GigaPan website and represents the panorama displayed above.

The imagery was collected in about an hour (half an hour flight time) and processed on the computer in about four hours. Both the 3D model and the orthophoto mosaic shown in this GigaPan are accurately located in space with an accuracy of 10cm. Readers are encouraged to visit the link below to see the equipment used and the 3D model of the mound and terraces.

www.personal.psu.edu/nmc15/blogs/anthspace/2011/04/super-simple-kap-and-photoscan-example.html