3D Laser Scanning
Three-dimensional
laser scanning is a rapidly developing technology that facilitates a
wide range of very high resolution, high accuracy spatial mapping.
Though originally developed for demanding engineering and medical
research, three-dimensional laser scanning can be easily applied to
the recordation of cultural resource properties of all sizes.
Laser scanners have greatly improved the accuracy, resolution, and speed of mapping and recording everything from geological profiles to archaeological sites to roadways and buildings. Data collected with this method are flexible, and commonly used in a variety of CAD, GIS, and ASCII formats. Increasingly, this once cost-prohibitive technology is becoming available to environmental and cultural resources professionals. A robust complement to GPS and survey data, laser scanned data sets show promise in more conventional CAD and engineering environments. Due to its accuracy, resolution, and simplicity, three-dimensional laser scanning is quickly developing into a powerful resource management and project planning tool.
GMI has been directly involved in the adaptation of 3D laser scanning for recording cultural artifacts, site contexts, and buildings since 2000. Geo-Marine has been at the leading edge of this development due to the following factors:
- The need for efficiency and accuracy in recording complex 3D features (burials, pit houses, etc.) and site contexts
- The need for improvement of the 2D recording techniques (accuracy is lacking) that have proliferated in the past five years
- The need for providing a media for the efficient sharing of data with fellow professionals
- The need for enhancing opportunities for public outreach.
GMI views 3D laser scanning technology as a necessary tool in providing cost-effective, quality services and providing data in a format that is of interest to the broader public. Our team has experience in:
- Close-range laser scanning
- Hybrid 3D scanning
- Long-range laser scanning
Related Projects
Petroglyph Documentation Using Three-Dimensional Laser Scanning, Parks Canada and the Royal Alberta Museum
Writing-On-Stone
Provincial Park is located in south-central Alberta, Canada. The
park protects the largest concentration of native rock art on the
Great Plains. Geo-Marine, Inc., was subcontracted by the Royal
Alberta Museum to conduct a small test of the feasibility of using a
laser scanner device to record petroglyphs at Writing-On-Stone
Provincial Park. Fieldwork was conducted over two days on July 6 and
7, 2005, by a combined team of Geo-Marine, Royal Alberta Museum, and
Parks Canada employees.
The petroglyphs selected for this trial project record the prehistoric/historical-period cultural transition of southern Alberta. Two panels used for the current study are located on large sandstone cliffs. One small replica panel was also scanned.
GMI used a Vivid 900 non-contact 3D digitizer to conduct the scanning. Because the petroglyphs at Writing-On-Stone were extremely shallow and faint, Geo-Marine, Inc., scanned the rock surface in dozens of small, high-resolution shots, and then produced a mosaic of all shots together to create an overall model.
Three Dimensional Digital Database of 725 Archaeological Artifacts
Development
and implementation of a three-dimensional digital database of 725
archaeological artifacts to facilitate cultural resources curation
requirements at Fort Hood, Texas.
Three-dimensional scanning has the potential to alleviate a persistent problem in archaeology: the unavailability of artifacts to both researchers and the public. Artifacts that must be curated, stored, or repatriated can be recorded and used for digital comparative collections or educational material. Such data availability opens the door to better comparative analysis and public awareness. The project was successful in developing a three-dimensional digital database that improves the business process of curation so that research, Native American consultation efforts, and public education objectives are facilitated at Fort Hood.
Wilson County Bridge 3D Laser Scan and Seguin Creek 3D Visualization
GMI completed scan post-processing and integration, and basic solid modeling for these 3D visualization projects. Ten scans were done at the Seguin Creek site. Because the scans at Seguin Creek were done in tandem with professional surveying, the Seguin Creek model is completely georeferenced. Despite some vegetation removal, the preponderance of vegetation and debris makes solid modeling of this site challenging. However, by carefully decimating the data, an accurate and detailed contour map was generated.
Forty-eight scans were conducted of the Wilson County Bridge structure from a number of locations above, below, and on either side of the bridge. Two Cyrax units were used simultaneously at the site—one taking detail scans from a close range, and the other focusing on recording the overall structure. Four very close-range detail scans were done with a Minolta Vivid 900 at the bridge as well. These scans included two details of the Carnegie imprint on the steel beams, a load-bearing joint on the deck of the bridge, and a support articulation underneath the bridge. The project methodology was designed in order to thoroughly record the bridge structure such that all meaningful construction details would be identifiable. For example, model resolution was hoped to be of high enough quality to illustrate fasteners such as bolts. Recordation quality and completeness was intended to be great enough to serve as a basis for HAER Level I-type engineering drawings.