Q+A CENTER

Given the preceding studies, it’s somewhat surprising that none enjoined state-of-the-art laser scanning. The value of any 3D surface profiling is incontrovertible: it acquires realistic digital information which, in event of damage, would form the basis for accurate replication and reconstruction. Those data also could bolster innovative, interactive public interpretation exhibits including potential virtual tours, support further research and help enhance security.

Earlier this year, the National Park Service assembled the Memorial’s industrial ropes team, scanning specialists from the Kacyra Family Foundation and their CyArk project (Oakland, Calif.), representatives of Historic Scotland (Edinburgh), the Glasgow (Scotland) School of Art, as well as technical consultants from Respec Engineering, Inc., Wyss Associates, Inc. (Rapid City, S.D.) and the South Dakota School of Mines and Technology (Rapid City).

The Mount Rushmore endeavor also employed an amalgam of instruments, mounted on tripods, along with four devices developed by Leica Geosystems (Norcross, Ga.): ScanStation 2, HDS6100, HDS6000 and ScanStation C10. Headquartered in Heerbrugg, Switzerland, Leica Geosystems is part of the Hexagon Group (Stockholm, Sweden).

The Leica scanners were placed strategically across the site to exploit their strengths. ScanStation 2, for example, with robust long-range capabilities was used along the base of the mountain. Models 6100 and 6000, with dense data capture capacities, collected all of the canyon’s nooks and outcroppings: HDS6100 acquired the fine facial details while HDS6000 was turned on the park grounds. Owing to a blend of range and speed, ScanStation C10 proved to be the workhorse for wide-area scanning. Each model utilized a unique data format, requiring voluminous notes and computer folders to keep track of daily scans from the disparate machines.

The complex, often precarious positions necessary for staging the equipment—vertically, sometimes upside-down and exposed—was undertaken by Hermanson Egge Engineering, Inc. and All Metal Manufacturing, Inc. (both based in Rapid City, S.D.). Those companies fabricated and installed one-of-a-kind scaffolding and structural riggings that facilitated access to essential areas and provided stabilized platforms from which to conduct scanning operations.