NON-CONTACT 3-D SCANNING OF PREHISTORIC FOOTPRINTS AND ART WORK AT A CAVE IN MISSOURI*
Last updated 10-29-2010
Expedition date: September 25, 2010
*The “cave in Missouri” has human footprints, bear paw prints and artwork, possibly dating back more than 500 years when it was sealed by a cave-in at its entrance. In exchange for generous access for scientific exploration and study, the landowners of the cave have requested that the location remain secret, in order to maintain their privacy and insure the cave and its rare artifacts are preserved.
On behalf of:
The Missouri Humanities Council and National Endowment for the Humanities, Cave.Archaeology.Investigation.Research.Network. (CAIRN), Missouri Caves & Karst Conservancy (MCKC), Springfield Plateau Grotto and Meramec Valley Grotto and Missouri Humanities Council, University of Kentucky Center for Visualization and Virtual Environments (CVVE), University of Kentucky Blazie Professorship and Transylvania University.
In a collaborative effort, teams from CAIRN (Craig Williams et al), MCKC (Jon Beard), the University of Kentucky Center for Visualization and Virtual Environments (CVVE) (Hassebrook et al) and Transylvania University (Begley) entered a cave in Missouri to capture 3-Dimensional scans of human footprints, bear paw prints and cave art. The cave is believed to have been sealed by a cave in at the entrance artifacts carbon dated to 1435 A.D, thereby preserving human footprints, cave artwork, bear paw prints and bear dens. The cave opened up in 1985 by a natural sink hole. We entered the cave through the sink hole by rappelling and lowering equipment by rope. The Scanner we used is based on Structured Light Illumination (SLI) and is battery operated for remote scanning without a generator. Hassebrook’s group has significant experience in SLI Research and Development and are well known innovators in the field. The team was able to acquire ten 3-Dimensional scans of human foot prints and bear paw prints, and six 3-Dimensional scans of the cave art. The number of points in the 3-Dimensional data was around 2 million 3-Dimensional points. In addition to the 2Meg point clouds, the scanner captures an 18 million pixel color image. The point cloud and the color image can be combined into a single color 3-Dimensional scan. Every point has an RGB color value and an XYZ coordinate accurate in span to less than 1mm and point space accuracy of about 60 microns. The technique, developed at the University of Kentucky is called mixed resolution 3D scanning. The idea is to not limit what archaeologists already have. That is, keep the existing high resolution digital photography, but add the value of 3-Dimensional coordinates to every pixel which allows for scientific measurement. The team worked on two sites in the cave, one were the human footprints and bear paw and the other, known as the “art gallery” where the cave art is. The expedition was a complete success and the team was able to exit the cave, some by ascending by ropes and most by a cable ladder to the surface. The team is now in the process of analyzing the data and planning for future expeditions.
EXPEDITION PHOTO DOCUMENTATION
THE UofK PREPARATION
The University of Kentucky and Transylvania University members prepared by taking rope training with Keenan Connor and Red River Outdoors (Slade, Kentucky) in Red River Gorge, Kentucky.
(Left to right) Larry Hassebrook, Chris Begley, Eli Crane, Keenan Conner and photographed by Bill Gregory. Cliff at Red River Gorge.
Missouri Caves & Karst Conservancy (MCKC). Jonathan Beard.
CAIRN: Craig Williams, Adam McBrady, Jessi Hicks.
Specialists: Bill Heim (cave specialist), Charley Young (photographer; cave specialist), Alicia Lewis (cave specialist) and Jack Rosenkoetter.
University of Kentucky, Center for Visualization and Virtual Reality: Blazie Professor Laurence G. Hassebrook, Eli Crane and Bill Gregory.
Transylvania University: Associate Professor Christopher T. Begley.
Left to Right in view: Craig, Jessi, Bill, Alicia, Larry, Chris. Left to Right: Bill, Charley, Jon and Craig.
Larry looking at scanner Larry, Eli, Jessi and Craig discussing the project.
Bill, Bill, Craig and Jon preparing to enter the cave. Jon and Craig at entrance of cave.
IN THE CAVE
Looking up at cave entrance shaft. Larry and Chris with gear near entry point.
Close to far: Larry, Chris, Eli and Adam following path to the footprints. Wide angle view of primary room.
THE FOOTPRINTS AND BEAR PAWS
Larry and Chris catching their breaths. Larry setting up for first scan.
(left) Jon and Larry preparing for scan. (right) Jon, Larry and Chris preparing the scanner. (All praying we don’t drop the scanner on the print!)
Targeting the Scanner. Eli and Chris performing scans of bear paw prints.
Targeting the impression. Setting up for bear paw print scans.
Bear paw prints. Waiting for a boot up.
Larry, Craig, Adam, Jessi. Targeting a different set of human climbing toe prints.
Adam showing our team how to get to the foot impressions. Part of team at the entry site.
THE ART GALLERY
(left) Prehistoric torch mark “Z” used for dating the time period of human access. (right) UofK/Transy team, Eli, Larry, Chris and Bill G. targeting the cave art.
Larry and Bill G. setting up for cave art scans. Targeting cave art.
Alicia and Craig exploring another location of cave art. More cave art inside small room.
EXITING THE CAVE
Traveling from the art gallery back to entry site.
Preparing to exit.
Out of the cave and very muddy.