digitizing
the
We are missing data on
“Washington’s
brow and cravat.
”
The screen showed black shadows in comparison
to the bright intensity colors of the scans.
Even with the data
“from
the scans on
the talus slope?
”
The angle is just too
“steep.
We have to
use the rig.
”
>> By Elizabeth Lee
Displayed with permission • The American Surveyor • Vol. 7 No. 7 • Copyright 2010 Cheves Media • www.Amerisurv.com
Legacy
What about the scans from
“Lincoln,
or the chins?
”
Two clicks brought up a
different modelspace.
No, the angle
“was
too oblique to
catch the front of
Washington
”
the rig
“toWbee designed
ambidextrous for a reason
”
This was the exchange that ultimately led to the Leica 6100 being suspended upside
down from a specialized rig developed to position the scanner against the presidential
faces of Mt. Rushmore...
Displayed with permission • The American Surveyor • Vol. 7 No. 7 • Copyright 2010 Cheves Media • www.Amerisurv.com
Maureen Young of the CDDV captures the sculptor’s scale model with the Leica C10.
he problem: we didn’t
have enough data
on Washington. We
needed a revolutionary
idea to complete the
scan of the hero of the
American Revolution. It was Day 13
of the first comprehensive laser scan
of America’s most recognizable faces.
Gathered in the data command center
were Douglas Pritchard of the Glasgow
School of Art and the Centre for Digital
Documentation and Visualisation
(CDDV), Justin Barton and yours truly,
both from CyArk, the non-profit working
to digitally preserve the worlds most
important cultural heritage sites.
Doug’s scanning expertise goes far
beyond the work at Mt. Rushmore to
other great projects like Rosslyn Chapel
in Scotland and the Schoenbrunn Palace
in Vienna. Leading the Scottish CDDV
team, Doug had planned and executed
all scans of the mountain. While Doug
coordinated the scanning teams and loca-
tions on the mountain, Justin had been
registering and reviewing data. Now,
with the project almost complete, the two
were working together to identify where
these last critical scans needed to take
place. After much discussion, the group
decided to “pull a 180” and position the
laser scanner upside down to complete
our scan of President Washington.
Thirteen days earlier the Scottish
CDDV and Californian CyArk teams had
arrived in Rapid City, South Dakota to
kick off the first international project of the
Scottish 10 as part of the CyArk 500 (see
note at end). The project brought together
a diverse team of surveyors, architects,
archaeologists, Harley-riders, ex-military
personnel, interpretive rangers, historians,
film makers, Americans, Canadians and
Scotsmen. It was put in motion in October
of 2008, when NPS Mt. Rushmore staff
approached CyArk about a solution for
digitally mapping the monument for
preservation as well as educational and
interpretive reasons. Discussions between
the park and CyArk continued in the
development of a plan, when in April
2009 the Scottish government made the
commitment to help CyArk and the
National Park Service. This commitment
came after CyArk founder Ben Kacyra
met with then Scottish Minister of
Culture, Michael Russell.
Upon learning of the CyArk 500
Challenge, Russell was inspired to
help the cause through the creation
of the Scottish 10 within the CyArk
500. Through the Scottish 10, Historic
Scotland and the Glasgow School of
Art would combine expertise to form
the CDDV. The CDDV is responsible
for the delivery of the Scottish 10, the
digital preservation the five UNESCO
world heritage sites in Scotland, and five
international sites. Mt. Rushmore was
selected to be the first international site.
Following a formal announcement of the
project at a July 4th celebration at Mt.
Rushmore, the teams got to work in planning the monumental undertaking.
Displayed with permission • The American Surveyor • Vol. 7 No. 7 • Copyright 2010 Cheves Media • www.Amerisurv.com
Positioned near Thomas Jefferson’s right
temple, Douglas Pritchard operates the
Leica C10.
Displayed with permission • The American Surveyor • Vol. 7 No. 7 • Copyright 2010 Cheves Media • www.Amerisurv.com
Douglas Pritchard of the CDDV scans
from “the chins” while the NPS ropes
team stands by.
The first step in the project was to
establish a site wide control network.
The network was developed and
executed locally. The Rapid City branch
of RESPEC Engineering installed and
located the control network on the mountain. Wyss Associates, Inc. Installed and
located the control network throughout
the park grounds. RESPEC Engineering
was also responsible for the integration
of the two control networks through five
common points throughout the park. The
placements of points on the mountain
were particularly challenging, with some
of the points only being accessible through
the help of the NPS Rope Access team
and the use of secure lines and harnesses.
The majority of the control network
was completed in April 2010. Additionally,
temporary control was established during
the terrestrial scanning portion of the
project. The temporary control in combination with the network was used to locate
scanning targets and geo-reference the laser
scan data sets to assure optimal accuracy.
Making their way up the mountain are (L-R) Alastair Rawlinson of CDDV, Kristina
Sturm of CyArk, Justin Barton of CyArk, Chris McGregor of CDDV, and Douglas
Pritchard of CDDV (back row).
When the teams from CyArk and the
Scottish CDDV arrived in May, they
brought an array of scanning technology
to provide both engineering-grade data
for tasks such as rock-block monitoring,
analysis, and site resource management,
as well as a base data set to create virtual
tourism and educational materials for
public outreach and data dissemination.
Complete coverage of the sculpture
was a necessity for the engineering and
interpretive needs of the park, therefore,
Displayed with permission • The American Surveyor • Vol. 7 No. 7 • Copyright 2010 Cheves Media • www.Amerisurv.com
it was critical that all surfaces be scanned
at a high level of accuracy and resolution.
A special tripod rig was designed by
CyArk, engineered by Hermanson Egge
Engineering, and manufactured by All
Metal Manufacturing locally in Rapid
City. The rig was used to capture views
of the sculpture that could not otherwise
have been obtained. The biggest design
challenge was to minimize the vibration
and deflection characteristics of the
tripod rig. Hermanson Egge Engineering
was able to meet the stringent deflection
and vibration characteristics using lateral
bracings. The weight of the rig was also
critical in the design, as it had to be as
light as possible for easy maneuverability
by the NPS Rope Access team. The rig
was ultimately made from aluminum
tubes instead of heavier carbon steel.
What arrived at the site was a piece of
engineering artwork, complete with a
beautiful bright yellow powder coating.
With five scanners, 11 DSLR cameras,
a huge supply of targets and tripods,
and the newly constructed tripod rig, the
team was ready for anything when they
arrived on site in May. Unfortunately,
the team’s arrival at Mt. Rushmore
coincided with several inches of snow.
In addition to the snow, while on site
the team experienced everything from
rain, to snow, to heavy fog, to brilliant
sunshine, to tornado warning winds, to
hail the size of golf balls, to perfectly calm
days. It certainly kept things interesting.
Thankfully the team was flexible on their
work hours, even starting as early as 5:00
a.m. to make the most of the good days.
Given the snow and rain the first week
of the project, the only thing to scan was
the interior of sculptor Gutzon Borglum’s
studio. This data will be used to create
a tour of the studio and Borglum’s scale
models used to design the sculpture.
Borglum designed on the scale model in
his studio and carried out his vision on
the mountain. Although Borglum’s model
of the sculpture shows the presidents
sculpted complete to their waists, that
amount of detail on the actual sculpture
was never completed. The scans and
video fly-throughs created from the data
will be particularly useful to the park for
interpretation during the winter months
when the studio is closed to the public.
Through the rest of the two weeks on
site, the team captured 224 scans, over
a hundred of those on the mountain.
The project deployed up to three capture
teams operating five scanners at once,
The highly adept NPS Rope Access Team members were critical in moving and
positioning “the rig”.
Displayed with permission • The American Surveyor • Vol. 7 No. 7 • Copyright 2010 Cheves Media • www.Amerisurv.com
Initial scanning results are shown here in plan view. The image shows 116 scans registered of the 224 total scans captured.
in various locations throughout the
park and on the mountain. Four Leica
manufacture scanner models were used:
the ScanStation 2, the HDS6000, the
HDS6100, and the new ScanStation C10.
Each scanner model was strategically
placed within the site to utilize its unique
strengths; for example the ScanStation 2
with its long-range capabilities was used
along the base of the mountain. The
speed and dense data capture abilities
of the 6000 and 6100 were used to
capture all of the details in the canyon
behind the sculpture and throughout
the park grounds. Because of its blend
of range and speed, the C10 was used
as the workhorse atop the mountain for
wide-view scans of the sculpture.
The onboard controls on the C10
and 6100 were essential to using the
scanner in precarious positions on the
mountain. In one setup location, the NPS
ropes team and Douglas Pritchard of
CDDV repelled with the scanner from
atop the monument down to the top of
Washington’s shoulder. With the scanner
secured on the shoulder and the scan
settings selected, Pritchard and the ropes
team then repelled off the side of the
shoulder to avoid obstructing the scan.
To ensure accuracy and complete coverage of the mountain, a data command
center was set up on site, and all team
members were equipped with two-way
radio systems. CyArk’s Justin Barton
used Leica’s Cyclone software to do daily
registrations of the data. This allowed the
scan-team members on the mountain or
on the visitor’s trail to radio the command center for up-to-date information
on the scans and instant feedback on
proposed scanner setup locations.
At the end of the two-week period,
the team had achieved incredible results.
Not only had the team captured the
mountain, but the majority of the park
had also been mapped in 3D. The initial
registrations were looking really good,
with just a few areas missing. Committed
to see the project successfully completed,
several team members extended their
stays in Rapid City to execute the final
scans. It was ultimately decided that the
final necessary scans would be done with
the tripod rig. The team had already
executed several scans with the rig and
achieved good results, so final scans were
not considered to be a problem. There
was one catch. The scanner would be
inverted on the rig, hanging the machine
Displayed with permission • The American Surveyor • Vol. 7 No. 7 • Copyright 2010 Cheves Media • www.Amerisurv.com
Jimmy Manuel of the NPS Rope Access Team manipulates the lines to help lower the scanner.
upside down from Washington’s brow,
several hundred feet above the ground.
The team pulled it off without a hitch.
Arriving at the park at 5 a.m. that morning, the team ascended the mountain as
the sun was coming up. After rotating the
plate that held the scanner 180 degrees,
the scanner was placed into a special
locking tribrach and positioned on the
rig just behind Washington’s head. Then
the ropes team went to work. Exchanging
technical commands, the team lowered the
rig into position on Washington’s brow.
Once in place and secure, the command
was given and Doug Pritchard controlled
the scanner from a laptop within WiFi
range. The results were incredible. With
final scans complete, the ropes team
utilized the park high-line system to safely
transport all equipment off the mountain.
When combined with the other scans
of the project, these final scans resulted in
the first comprehensive documentation
of Mt. Rushmore. With the capture of
this American icon complete, CyArk and
Scottish teams are now at work creating
the engineering and educational deliverables to supplement the laser scan data in
the CyArk archive. There Mt. Rushmore
will sit alongside world treasures from
around the globe as the team takes on
the remaining sites in the Scottish 10
and works toward the completion of the
CyArk 500.
The Scottish 10 is a collaborative
project between Historic Scotland, the
Glasgow School of Art Digital Design
Studio, and CyArk to digitally preserve
10 significant heritage sites.
The CyArk 500 is a global effort to
digitally preserve 500 of the world’s
most important heritage sites.
The Mt. Rushmore Digital Preservation
Project is a five-year partnership between
the United States National Park Service
and the Kacyra Family Foundation/ CyArk.
The laser scanning portion of the project
was made possible through the generous
contribution of the Scottish Ministers as the
first international project in the Scottish 10.
Originally trained as an archaeologist,
Elizabeth Lee has conducted
fieldwork for CyArk all over the world.
Prior to joining CyArk, she founded the
UC Berkeley/CyArk Visualization Lab
and served as instructor for the UC
Berkeley/CyArk Internship Program.
Ms. Lee currently directs all aspects
of CyArk’s digital preservation project
work and development, as well as
professional development, training
and university outreach.
Displayed with permission • The American Surveyor • Vol. 7 No. 7 • Copyright 2010 Cheves Media • www.Amerisurv.com