UAS Maps Lost Pyramids In The Andes

Using a small, hand-launched, Unmanned Aircraft Sytem (UAS) equipped with a downward facing camera and a sophisticated autopilot system, archaeologist Mark Willis documented the site of the Pyramids of Zuleta as it has never been seen—from extremely low altitude and at high resolution.  This was a challenging task as most of the pyramids are located in the bottom of steep constricted canyon inhabited by Andean Condors.  To make things more challenging there were high winds, clouds, and quirks of the micro-climates within the canyon to contend with. In spite of that, the team was able to fly nine missions and collect hundreds of photographs in just a couple of days.

The Pyramids of Zuleta are one of the hidden treasures of the Andes.  Built around 1,000 years ago, by the native Caranqui people, these earthen mounds and platform pyramids dominate the landscape near Hacienda Zuleta.  Unlike much of our planet, high resolution aerial imagery and digital elevation models are unavailable for this part of the world.  This is due to the fog that often blankets the area and the agrarian nature of the region. As a part of a team of archaeologists who visited the site in the August 2013, Willis aimed to change that.

The UAS flies in a defined pattern and as it collects photographs. The onboard autopilot insures that each image has 60% or more overlap with adjacent images.  These overlapping images allow for the data to processed into 3D and digital terrain models (DTMs) using photogrammetric and cutting edge Structure from Motion technologies.  All of the data are GIS ready.

While basic processing allowed the team to see the mapped data in the field, it was necessary to further develop it using a high-end processing farm in Maryland, once they were back in the States.This approach has already led to the discovery of many more mounds that are not obvious to the naked eye but stand out in the data.  Furthermore, it is the first time the detailed spatial relationship between each of the earthen structures can be explored with precision.  This data will be used to track the condition of the mounds over time and has created a digital snapshot of their current state for future generations to ponder. This was accomplished with only a few days of fieldwork and under harsh conditions.  To create a map of similar accuracy using traditional survey approaches would have taken weeks and lacked the aerial imagery this approach provides.

Sources: Markaelogy Blog; YouTube

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