Laser Design Surveyor RPS-120 probe:
(excerpted from Laser Design, laserdesign.com)
Laser Scanning Creates Online Virtual Museum for Researchers Worldwide
Institution: Marshall University is a state-supported university with 2-year and 4-year undergraduate and graduate programs located in Huntington, WV. It is accredited as an institution of higher learning by the Commission on Institutions of Higher Education of the North Central Association of Colleges and Schools.
Dr. Suzanne Strait of the Biological Sciences Department specializes in vertebrate paleontology. She has been creating research projects with funding from the National Science Foundation (NSF) for over 10 years.
Project: Dr. Strait first became interested in scanning technologies while writing her thesis on the comparative anatomy of fossil mammal teeth. She used an electron microscope to make 2D scans of her specimens. This rudimentary scanning method took enormous amounts of time and did not provide the three-dimensional data necessary for researchers to manipulate the objects and see the 3D shapes or take realistic measurements for comparisons and study.
In order to advance her research, Dr. Strait kept abreast of the new scanning technologies being developed in industry. When she heard about 3D laser scanning, she knew it would be ideal for her purposes: faster, more accurate, easier to do, non-contact, and in 3D. She envisioned creating a website as an online virtual museum for researchers to view fossils in 3D and download functions so they could manipulate, measure, and compare them. “Fossils are a rare commodity, each one unique and housed in widely dispersed museums around the world, so access is very limited,” noted Dr. Strait. Having an online museum that displayed lifelike, virtual images would be a valuable research tool for paleontologists and other scientists, giving them access to many objects without having to travel to remote locations.
Dr. Strait’s groundbreaking project, first funded by the NSF in 1997, allowed her to research laser scanning technologies and purchase the Laser Design Surveyor RE-810 3D laser scanning system in 2000. Laser Design, Inc., based in Minneapolis, MN, has been the leading supplier of ultra-precise, 3D laser scanning systems and services for over 20 years. The RE-810 is an affordable desktop 3D scanning system with the European CE Mark that is well suited for scanning small, highly-detailed fossils and artifacts like bones and teeth, and therefore popular with anthropologists, archeologists, and paleontologists in museums and universities. The system scans parts from all orientations and easily merges the data into a common coordinate system known as a “3D point cloud”. The rotary stage automates the scanning process making it even easier and faster.
Further NSF funding (nearing the $2 million mark) for projects spanning the years 2002 until 2009 has allowed Dr. Strait to continue building on her original project using the Laser Design Surveyor system to scan fossils obtained from North American dig sites and post them on the interactive virtual museum website.
The fossils in question are from the Paleocene-Eocene boundary era, approximately 55 million years ago, which the most pronounced period of global warming during the entire period that mammals dominated the earth. Many mammals which first migrated to North America at the beginning of this period dispersed during the warm interval. This “Paleocene-Eocene Thermal Maximum” period impacted terrestrial and marine ecosystems worldwide. The fossil record provides understanding into the consequences of climatic change on Earth’s modern plant and animal species and gives us indicators as to what the effects of our present-day human induced climate change will be in the future.
At the outset of the research project, over 3000 early Eocene mammal specimens were unearthed in the southeastern Bighorn Basin of Wyoming. The recovered specimens along with others borrowed from museums around the world will be laser scanned and documented in Paleoview3D (http://paleoview3d.marshall.edu), the online database/museum. Creating a database of this type is unique and provides a model for institutions on how to make their collections easily accessible and useful to researchers everywhere. The project also allows students to participate in the research in a very hands-on way. By learning to scan and catalog specimens, they are exposed to modern field methods and high-end, state-of-the-art technology.
Method: PaleoView3D is an interactive 3D model library that will eventually display over 700 fossil specimens from 20 museums. So far 37 are available online. Dr. Strait and her students started scanning fossils in 2000 on the Laser Design Surveyor 3D laser scanning system. At the time of purchase, the system was still running the original Laser Design proprietary data collecting and editing software in UNIX. Since the system “operators” were biology undergraduate students, not computer scientists, the software was cumbersome and hard to work with. However, soon thereafter, the system was updated with the new Surveyor Scan Control (SSC), the Windows version of the software with enhanced functionality and ease-of-use, so the scanning and modeling processes became much easier for the students to perform. SSC controls the scanning motions, manages the laser probe settings, and contains advanced automation features.
The Surveyor 3D laser scanning system’s patented laser probe technology dramatically reduces scanning time by collecting data significantly faster and more accurately than with other technologies. Because the laser scanning system projects a line of laser light onto surfaces while cameras continuously triangulate the changing distance and profile of the laser line as it sweeps along, the problems of missing data on an irregularly shaped surface is eliminated. This laser line is much like spray painting the part with points, moving back and forth until the complete part is captured. The system measures fine details and captures complex freeform geometry so that the object can be exactly replicated digitally. Laser scanners measure articles quickly, picking up tens of thousands of points per second, and generating huge numbers of data points without the need for templates or fixtures.
The Surveyor system’s laser, a high accuracy RPS-120 probe with a high scan density, is ideal for small and medium-sized specimens with fine detail features. Oftentimes, the fossil specimens to be scanned were very small; for example some teeth were only 1-2 mm². “We require excellent precision to scan such small artifacts. The resolution level of the probe is very good. It produces a very dense point cloud of coordinates (.001”, .025 mm) so our measurement data is very accurate,” commented Dr. Strait. The RPS laser probe features a Class II rating with a visible beam, for safe and easy-to-see operations and a long standoff to prevent crashes during dynamic part scanning, which is very important when inexperienced student operators are performing the scans.
Many of the specimens included in the virtual research museum are teeth and bone fragments. Dr. Strait continued, “Isolated elements, such as a tooth or femur, are easier to scan. Bone groups, such as a jaw bone with teeth, are more challenging to scan and require multiple scans to gather enough 3D data to create an accurate, detailed 3D model. Most of the fossils are tiny, less than 1 mm, and have lots of undercuts.” Scanning free-form detailed shapes, however is non-contact laser scanning’s forte, and the student operators easily pick up scanning techniques. Since the objects are relatively small in size, the scanning process can be completed in less than an hour even though the specimens must be scanned from several orientations. After scanning, the data is merged and edited, then converted into surface models, or reverse engineered, in Raindrop Geomagic Studio 7.0, which takes more time, usually a few hours, to complete.
Results: The PaleoView3D database currently focuses on North American late Paleocene and early Eocene mammals . Further expansion is planned to include more species and time periods. Ideally, every “type” of animal fossil from the period will be represented in the future, so researchers can contrast and compare the online models with other fossils for identification purposes and further study.
The data collected by the Laser Design Surveyor system are extremely detailed. Many of the technical specifications listed with the specimens come directly out of the laser scans and the Laser Design SSC software used to create them. The surface models are high resolution images that can be viewed in 3D, magnified and rotated. Simple measurements (i.e., linear distance, circumference, and arcs) of each model can be made directly on the web-site with a basic point-and-click feature. Each image can also be downloaded as a data file so that more sophisticated 3D measurements can be made using CAD, GIS, or 3D measurement software.
The PaleoView 3D website database is rich in many types of information regarding the specimens, such as specimen number in the original museum and pertinent hyperlinks and reference lists, detailed locality and age of fossil, skeletal element, descriptive narrative of the species, and year collected, to name a few.
The website also details the technical aspects of the laser scanning, such as number of scans performed, number of coordinate data points, exposure or the probe CCDs, and linear spacing of the scan lines.
“We have made amazing progress on the PaleoView3D database thus far. With the remaining two years of project funding, we will be able to make it a truly useful tool for researchers all over the world,” concluded Dr. Strait. “We hope to be a leader in what will be an explosion of online databases, an innovation possible because of the advancements in the field 3D laser scanning found in our Surveyor system from Laser Design.”
About Laser Design: Laser Design, Inc. has been the leading supplier of ultra-precise, 3D laser scanning systems and services for over 20 years. Used for capturing the 3D shape of objects with complex geometries and free-form surfaces, Laser Design’s Surveyor line of automated and portable scanning systems are ideal for 3D scanning applications involving inspection and reverse engineering of complex shaped plastic and metal parts. The company’s patented laser line-probe technology dramatically reduces scanning time by collecting data substantially faster and more accurately than conventional metrology technologies. Laser Design integrates Geomagic software with its laser scanners to provide complete solutions for reverse engineering and inspection applications.
For further information, contact Rick Passek, by phone (952-252-3412), fax (952-884-9653), via email to email@example.com or visit Laser Design’s web site at http://www.laserdesign.com