Tracing ancient settlements in Colombia with remote sensing

A team of the LDE alliance (Leiden University, TU Delft, and Erasmus University Rotterdam) asked whether it might be possible to search for signs of ancient settlements in the jungle with affordable remote sensing techniques. For an expedition in a Colombian dense forest, the team, including remote sensing expert Felix Dahle of TU Delft, joined forces with archaeologists and drone experts from Colombia. 

In mountainous forests, drones provide affordable access to areas that would otherwise be unreachable from the ground. A LiDAR laser scanner already proved its value in coastal observation. The big question was whether LiDAR could bypass the many treetops. Trees reflect the laser, so it was crucial to fly close so it found its way through the foliage. The team mounted a highly portable LiDAR laser scanner to a drone and went on expedition nearby ancient terraces of the Tairona culture in the Sierra Nevada of Santa Marta.  

“We had to find the sweet spot. Close to the archaeological sites and still secure above the canopy”, says Felix Dahle. And it passed the test. The LiDAR laser scanner create a point cloud and a detailed 3D model of the landscape. “We were able to detect ancient terraces in the jungle. We discovered that we can scan through the forest when it is not too dense, but some areas remained unfathomable. We could also distinguish several types of vegetation, which might be of great use too to find undiscovered archaeological sites.”