Chad Keller

1. Non Invasive Techniques for
Documenting Historic Cemeteries
Structure from Motion, Colonial CemeteryLaser Scanning , Laurel Grove Cemetery

2. Laser Scanning
 Faro Focus 3D
 Phase-based scanner
 40 million points in 10 minutes
 Accuracy within 1/8th of an inch
 On board camera
Yuen Mansion ca. 1920, Lantau Island, Hong Kong

3. Laser Scanning

4. Laser Scanning
 Laser scanning
involves three-
dimensional point
capture.
 The points are
oriented in a point
cloud and are a
representation of
three-dimensional
space.
Historically Black Cemetery, Grove Point Plantation

5. Laser Scanning
 Approximately 30%-50% overlap
required between scans
 Multiple scans are unorganized
until they are registered
St. Helena Chapel of Ease ca.1740

6. Laser Scanning
Manual Registration
Manual registration involves
manually identifying points between
scans.
Automatic Registration
The software automatically registers
the scans using targets that are
placed around the site.
Barboursville ca. 1822 destroyed 1884 , designed by Thomas Jefferson, Barboursville, VA

7. Manual Scan Registration
 Scan Registration
 High Resolution

8. Laser Scanning
 Create two-dimensional
drawings
 Three-dimensional CAD
models
CAD drawings of Lot 988, Laurel Grove Cemetery

9. Structure from Motion
 Based on photogrammetric
principles, but creates a
three-dimensional model from
two-dimensional images.
 Point and shoot camera
 Density of point cloud
dependent on the size of the
images
Historically Black Cemetery, Grove Point Plantation

10. Structure from Motion
Point cloud and image locations

11. Structure from Motion
Polygonal mesh

12. Structure from Motion
Photo textured model

13. Laser Scanning vs. Structure from Motion
Laser Scanning Photogrammetry
Pros Pros
•Accuracy within ¼ of an inch
for most scanners
•Accuracy over large spaces
•Captured at true scale
•Significantly cheaper
equipment
•Better visual representation
of textures
Cons Cons
•Equipment can be
prohibitively expensive to
own
•Generally need to upgrade
physical equipment to keep
up with progress
•Accuracy is lower than
laser scanners over large
space
•Scale limitations based on
camera lenses maintaining
clarity over long distance

14. Wild Heron and Grove Point
Google Maps

15. Wild Heron and Grove Point
Rice mill ruins Irrigation channel

16. Wild Heron
Marked graves

17. Wild Heron
Grave depression

18. Wild Heron
Numbered flag

19. Wild Heron
Marking depressions

20. Wild Heron
Recording with total station

21. Wild Heron
Depressions plotted in Autocad

22. Wild Heron
Depressions recorded in ArcMap

23. Grove Point
Well-maintained and still in use

24. Grove Point
Grave markers

25. Grove Point
Well-maintained and still in use

26. Grove Point
Structure from MotionLaser Scanning

27. Grove Point
Registered point cloud

28. Grove Point
Markers georeferenced in ArcMap
 Georgia Individual
marker survey
form