SITKA NATIONAL HISTORICAL PARK - Following in the footsteps of Sitka National Historical Park’s first custodian, E.W. Merrill, whose photographs from the turn of the century documented the arrival of the totem poles to the park, two specially trained architects will laser scan the park’s totem poles this weekend, preserving them digitally for a permanent collection in the Library of Congress archives.
Starting June 28, the two-man team will scan the totem poles with a high-definition, three-dimensional laser scanner, and then mask the wireframe of data points with high-resolution images to create a 360-degree virtual view of the poles - the first time such technology has been used on carvings of this size by the National Park Service. They will wrap up scanning on June 30.
“We have employed a variety of methods in the past 100 years to preserve these unique cultural objects. This high-tech documentation both helps serve that preservation mission, and expands the audience able to experience our park," said Sitka NHP Superintendent Mary A. Miller.
The team from the National Park Service’s Heritage Documentation Program in Washington, D.C., will also document the Russian Bishop’s House, recording a detailed floor plan with tape measures and digital range finders, and laser scanning the exterior and significant interior rooms, including the restored 19th century Russian Orthodox chapel and reception room.
The three-dimensional laser scanner is similar to radar, except the scanner measures distance with a point of light rather than sound. Placed on a stand in the center of a room, the device fires a rapidly pulsating beam of light outward from its rotating and oscillating sensor head. Each time a beam returns from bouncing off a wall, ceiling, or object in the room, the sensor registers the distance, and logs a data point. Taking about an hour to complete a 360-degree view of a room, the resulting image appears as a series of closely spaced dots, called a “point cloud."
The scanner is capable of recording images in the dark, and sensitive enough for rain to obscure the readout - a potential challenge while scanning the poles here.
Employing the use of a hydraulic scissor lift, the crew will take high-resolution photographs of the totem pole in three-foot sections at six angles. The architects will then upload images into a computer program that masks the scanned “point cloud" with the images taken of the totem poles.
The result: A high-resolution, vertical tour including a close look at each figure of the pole from the very top to the very bottom.
The drawings, photographs, and “point cloud" data of the park’s totem poles and the Russian Bishop’s House will be available to the public online at the Library of Congress’ Historic American Buildings Survey site: http://www.loc.gov/pictures/collection/hh/.
The virtual tour will be available in the future as an virtual feature on the Sitka NHP website, taking the National Park Service director’s Call to Action #17, “Go Digital!" to a new level of interactivity, and serving a broad range of online visitors who may never set foot on the trails among the totem poles of Sitka National Historical Park. Images from this scanning project will be used in the park’s new waysides that will be installed early next year.
Weather permitting; the crew will be scanning the totem poles on the Sitka NHP Totem Loop Trail June 27 to June 30. For media inquiries regarding the specific locations of the laser scanning documentation team in the park and interviews with subject matter experts, contact Ryan Carpenter at (907) 747-0132 or ryan_p_carpenter@nps.gov or Angie Richman at (907) 747-0121 or angie_richman@nps.gov.
Print-quality photographs of the documentation team at the Russian Bishop’s House are available upon request.
Source: U.S. Department of the Interior, National Park Service
