Mount Rushmore National Memorial is a well-known landmark, not only for Americans, but also for people all over the world. In this intriguing monument in Keystone, South Dakota, giant faces of four former U.S. presidents protrude from the granite rocks.
This historical site has now been thoroughly documented and analysed for future generations, using 3D technology from Hexagon. It was initiated by the non-profit organisation CyArk (www.cyark.org). CyArk’s focus is to digitally preserve the world’s most important heritage sites. This CyArk project, one of many performed using Hexagon 3D scanning tools, was done in conjunction with the United States National Parks Service, Historic Scotland and the Glasgow School of Art. During the project, interesting details were added to the view of Mt. Rushmore, with scanners placed on horizontal as well as vertical places, sometimes upside-down using specialised rigs. Using the scanners, it was possible to electronically save the exact features of George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln, or rather the 18 meters high reproductions of the former presidents.
To be able to evaluate the needs for preserving and developing the park, every detail of the rock-hard faces was registered, using Hexagon company Leica Geosystems scanners. The equipment was chosen according to the characteristics of the site. The need for long-range capabilities, speed and level of detail varied around the site. Adding to the dynamics of the project was the need to use rope teams, climbing with scanners on the memorial.
The gathering of data resulted in billions of measuring points along with more than
7 000 photographs. This massive amount of information was analysed using Leica Cyclone software, which also enabled members of the scanning team to have continuous access to up-to-date information on the scans and scanner setup locations.