NPS Photo by Amy Bracewell

Maureen Young from Historic Scotland preps one of the laser scanning stations to begin scanning Borglum's model in the Sculptor's Studio

Mount Rushmore National Memorial is in the process of a ground-breaking three-dimensional laser scanning project. Memorial staff will be using the latest laser scanning technology to create a highly detailed record of the sculpture and other historic resources at the park.

The value of the 3-D scanning provides realistic digital information of the site and has applications to provide innovative and interactive public interpretation, education, research and security programs. In the event of an incident resulting in the damage of the sculpture, the data would provide the information necessary to accurately replicate carved surfaces. The digital data will also give the NPS the ability to develop a very realistic interactive model for Mount Rushmore for education and interpretation including potential "virtual tours" of the memorial, as well as the entire site.

Scanning Team and Partners
The scanning team consists of members of the Memorial's technical ropes team, scanning specialists from the Kacyra Family Foundation and their project CyArk, Historic Scotland, and the Glasgow School of Art, as well as local technical consulting staff from Respec Engineers, Inc., Wyss and Associates, Inc., and the South Dakota School of Mines and Technology.

The scanning of Mount Rushmore is also a part of a scanning project called the Scottish 10 by Historic Scotland and the Glasgow School of Art. The goal of the Scottish 10 is to scan the 5 World Heritage Sites in Scotland and 5 international heritage sites, with Mount Rushmore as the first international site.

All of these projects, including the scanning of Mount Rushmore, are among the CyArk 500 initiative which is a global effort to digitally preserve 500 of the world's heritage sites.

Laser Scanning Process
Laser scanning accurately records the 3-D surface of objects in a digital form. The team uses a mix of lasers mounted on tripods including three machines developed by Leica: The Leica Scanstation C10, Leica HDS6100, and the Leica Scanstation 2. The scanners project millions of points which are collected and put together to create a 3-D model of the object being scanned. These points are called 'cloud points' by scientists and give will the information needed to create an extremely accurate 3-D model. Laser scanning is capable of capturing sub-centimeter details.

January 2012, update.

The field documentation at Mount Rushmore, including geo-referenced laser scanning and photography, took place in May of 2010. Teams from CyArk, Historic Scotland and the Glasgow School of Art (CDDV), RESPEC, and Wyss Associates, Inc. all worked together with National Park Service staff for over two weeks to fully document the sculpture and park grounds. In order to laser scan the face of the mountain sculpture completely, a special tripod rig was designed by the team, engineered by Hermanson Egge Engineering, and manufactured locally in Rapid City. The NPS ropes team repelled down the face of the mountain sculpture with this tripod rig and the laser scanner to scan the details of the sculpture that could not otherwise have been captured.

During the two weeks of field documentation, over 200 laser scans were performed, collecting billions of data points. In addition to the laser scan data collected, individual photographs and panoramic images were taken on the sculpture and throughout the park grounds. These images were used to photo-texture the laser scan data. All the data collected has been used to create a variety of media for digital preservation. This media will be used for the on-going preservation and conservation of the mountain and for public education and interpretation of the memorial. Visit site at http://archive.cyark.org/mount-rushmore-national-memorial-intro