Within recent years LiDAR technologies have been widely used to search for ancient ruins hiding under the tree canopy. The Olmec and Maya civilizations flourished in what are now Mexico and Guatemala as well as the lost Casarabe culture in Bolivia have been in a close focus for archeological studies. However, LiDAR surveying, particularly airborne, as a method to study tropical forests has opened new opportunities not only for archaeologists and not only in Latin America.
Unveil invisible
Airborne LiDAR, especially on drones, demonstrates extremely high capability to “see” through canopies of very dense jungles. In September of 2021 SPH Engineering team participated in an expedition to the Pacific region with the aim to conduct a magnetic survey of a certain area of an island in the middle of the ocean. As a preparatory step to gather elevation data the entire project area was surveyed using LiDAR mounted in a drone. Hi-resolution scanning of the area approx 3.2 x 1.2 km big took 1 full day, and actually 1 night for the data processing on a laptop computer.
‘Because of extremely dense tropical jungles and rough terrain with slopes, canyons, etc. (elevation change in the survey area was around 200m), initial expectations were to get a dense enough point cloud to build an elevation model of the ground as well as a digital surface model with grid density of around 1m,’ Alexey Dobrovolskiy, CTO at SPH Engineering, explains. ‘But after the data processing we found that even small features like fallen trees and hidden trails were unveiled in LiDAR data.’