Modeling Archaeology

– post by Tristan Harrenstein, Florida Public Archaeology Network

In the last few years, archaeologists have been getting excited by the potential for recent advances in something called photogrammetry. This technology takes a collection of photographs of an object, plugs them into a program (Agisoft PhotoScan in this case), and builds a digital 3D model.

This is exciting! Photogrammetry is already useful for research and education, but it is also changing the way we record archaeological sites. Dr. Kotaro Yamafune (Research Associate in Nautical Archaeology at Texas A&M University) has an impressive body of work using this technology to record underwater shipwrecks. After five days of photographing, he was able to generate highly accurate and easily manipulated maps that would normally take years and many divers. The use of photogrammetry saved money and people hours, without sacrificing accuracy or data.

Which brings us to the purpose for this blog post. Since there has been so much success modeling underwater archaeological sites, what potential does photogrammetry have for sites on land? Might this technology someday replace hand drawn maps? To test this, Barbara Clark and I visited Florida State University’s archaeological field school this summer and modeled one of their excavated units.

Might photogrammetry make mapping a thing of the past?  (Image courtesy of the University of West Florida’s Department of Anthropology)

One limitation of photogrammetry software is that it needs identifiable features so that it can figure out where each picture was taken in relation to the others. I was concerned that the unit walls would look too much alike for the program to align the pictures properly. As a result, we made two models of the same unit. The first set of photos were of the plain unit walls while the second set included some photo board symbols pushed into the sides to provide points of reference for the program.

Each blue square represents the location of a photo that makes up this model. Fortunately, Photoscan calculates this for us. 

 

The Results

To be clear, this experiment was not supposed to be definitive. The goal was to get some idea of how much potential there currently is for photogrammetry as a tool for recording terrestrial archaeological excavations and to better understand what equipment we would need. That being said, these models turned out far better than I had expected, with very little difference in quality between the two tests.

See an example of the terrestrial photogrammetry we did on one excavation unit at the FSU Anthropology’s 2016 Archaeological Field School HERE!

*Please note, these examples are using just 500k faces each. A much higher resolution of 25 million faces is possible, but not many computers can currently handle this.

As far as the equipment goes, we need better photographing methods. Even with the monopod, taking pictures of a unit this deep was difficult and uncomfortable. I spent a lot of time with my head in the unit, or standing at awkward angles inside the unit, trying to hold still for the camera while yellow flies gleefully seized upon the opportunity to grab a bite.

On the upside, the solution to this is relatively simple. All we would need is a pvc pole, a camera mount for bicycle handlebars, and a remote for our camera. This would take a few test shots to make sure the angle was correct, then the rest would be faster and much more comfortable. Throw in a white tent to help diffuse the light evenly and we should be in good shape.

But is this worth pursuing further? We certainly do not have the same limitations on land that our underwater peers do, and photogrammetry cannot replace hand-drawn profiles of unit walls any more than pictures can (due to a tendency to distort colors). Does this mean that photogrammetry has no current value for terrestrial archaeology?

Absolutely not. There are a lot of ways this technology could be invaluable right now. Do you have an artifact that you cannot take back to the lab with you? A few minutes of photographing means you can examine it later at your leisure. This also has excellent applications for complex features that do not just rely upon soil changes, such as brick structures. Photogrammetry models provide a sense of depth that even the most diligent hand-drawn maps or pictures cannot capture very well.

Mapping a feature like this one on 2D graph paper is very challenging and time consuming. Photogrammetry is already an improvement for a situation like this. (Image Courtesy of the University of West Florida’s Department of Anthropology.)

Mapping a feature like this one on 2D graph paper is very challenging and time consuming. Photogrammetry is already an improvement for a situation like this. 

In a nutshell, photogrammetry currently has some excellent, if situational, uses in terrestrial archaeology. Perhaps this will revolutionize the way we record sites, or perhaps it will just remain a very specific tool for a specific job. However, technology is advancing quickly and I would not be surprised if photogrammetry, scanning, or just tablets make hand-drawn profiles obsolete someday. We will need further testing to fully understand the potential of photogrammetry, but now is the time to begin.

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Tristan Harrenstein is trained as an archaeologist and has a passion for outreach and education. This is fortunate as he is also an employee of the Florida Public Archaeology Network, an organization dedicated to promoting the preservation and appreciation of our archaeological resources. He shares a blog space with his boss (Barbara Clark) and you can read more blog posts on other archaeology related subjects that tickle our fancy here.

On Location

If you recall from a few weeks ago, FSU Office of University Communications spent a few hours in the field with us to document our work and uniqueness of the archaeological field school as a hands-on learning opportunity for FSU students. Staff of the FSU Communications office – Nora Bertolaet, Digital Content Producer, Ryan Ruditz, Videographer and Editor, and their skilled crew produced a fabulous piece that we are all proud of.

Watch it for yourself! You will feel like you are “On Location with the FSU Department of Anthropology!”

 

 

 

Visitors, Photos, and Videos

On Thursday we hosted a number of visitors to our field site, in addition to our regularly scheduled volunteers and our partners at SEAC. Archaeologists with the Florida Public Archaeology Network came out to see our work and to experiment with photogrammetry.

FPAN Archaeologist, Tristan Harrenstein, takes shots of an excavated unit.

Tristan (FPAN) checking the pictures and how much life is left in the battery. You can see the plywood and plastic in the background that was put up so there unit would be completely in shade. The dappled shade/sun of the natural tree cover does not make for good archaeology photos.

 

We also had a visit by a retired soil scientist that has worked all over but is especially knowledgable about the soils in our area. We need to figure out if some of the sands we are encountering in our excavations are naturally occurring or if the people that lived here 1200-1400 years ago brought them to this specific location. If it is the latter, we then get to puzzle over (and hopefully answer) – Why?  Next week we will take sediment samples and cores of various parts of the site for further analysis.

We were very excited to host staff from the FSU University Communications office. They brought out a number of digital and video cameras to capture our work. It was wonderful to share our passion for archaeology and the excitement for what we are learning about the last people to live here is palpable. Nora Bertolaet, Ryan Ruditz, and their team were wonderful to work with and asked really great questions! We can’t wait to see the finished product (which we will post here of course)!

FSU University Communications staff learn about some of the tools and technologies used by people at this (and neighboring) sites over a thousand years ago. (They are interviewing Thadra Stanton, FSU Anthropology Alumna and current staff with SEAC.)

FSU University Communications videographer and assistants interview Dr. Tanya Peres about our work at the site and the FSU archaeological field school course.

The day after

We were anxious as we returned to the site this morning, unsure of the extent of any damage to our excavations from Tropical Storm Colin. On Friday of last week we took extra precautions when we covered the excavation units in anticipation of three days of rain – but that was before the rain turned into TS Colin! We are so glad we bought plywood and made extra efforts – they paid off!

Several of our excavation units covered with plywood and plastic. They worked!

In several of our units near the swamp (and on a downslope) we were not so lucky. We had to create a bucket brigade to get the nearly 40 cm of water out of the deepest unit!

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Fortunately for us, we are nearly finished excavating the units that were inundated. This means we can leave them to dry out over the next few days and finish our work in there later this week.

So, the crews that were in those units were sent to join the rest of the group and we opened three more excavation units to extend our view into the site. We still have lots of work to do as we uncover features and try to figure out the puzzle of the past, but we are having a great time! Thanks for reading!

Humans of FSU Archaeology

Dr. Tanya M. Peres, RPA                  

Associate Professor of Anthropology

Director, Maritime Woodland along the Florida Gulf Coast

 

 

I received my BA (1995) and MA (1997) in Anthropology at Florida State University and my PhD (2001) in Anthropology from the University of Florida.  Immediately following graduation in August 2001, I moved to Lexington, Kentucky to work at the University of Kentucky. While at UK I was  an Assistant Director of the Program for Archaeological Research and an Adjunct Assistant Professor in the Department of Anthropology (2001-2005). I was a member of the Sociology and Anthropology faculty at Middle Tennessee State University from 2005-2015 (and Director of the Anthropology Program from 2014-2015). In August 2015, I left MTSU to become an Associate Professor of Anthropology at Florida State University in Tallahassee, Florida.

I am a Registered Professional Archaeologist since 2001 and have over two decades of field and lab experience on academic and applied prehistoric and historic archaeological projects across the Southeastern United States, Panama, Mexico, and Scotland. I am interested in the relationships between humans and their environments, and humans and animals – especially in terms of subsistence and how animals were incorporated into the native worldview. As a zooarchaeologist I collaborate on numerous projects with local, state, and federal agencies, non-profit organizations, and Cultural Resource Management (CRM) firms. I research and publish on zooarchaeological topics ranging from ancient and historic subsistence practices to the use of animal bone and teeth implements in indigenous tattooing traditions to the symbolic power of animals in native cosmologies, medicine, and spiritual practices.

In 2010 I (along with Aaron Deter-Wolf and Shannon Chappell Hodge) was awarded an NSF RAPID grant, RAPID: Emergency Shoreline Assessment and Sampling of Archaeological Sites along the Cumberland River in Middle Tennessee, to assess the natural and anthropogenic damage to archaeological sites along the middle Cumberland River following the May 2010 floods in Nashville, Tennessee. This grew into the MTSU Middle Cumberland Archaeology Project, which is an on-going collaboration between FSU, the Tennessee Division of Archaeology, and several other local, state, and federal agencies, and private landowners to investigate and preserve ancient sites along the middle portion of the Cumberland River east and west of Nashville.

I have worked at a variety of sites across the Southeast while employed by CRM firms, the University of Kentucky’s Program for Archaeological Research, and the National Park Service’s Southeastern Archeological Center. My publication record includes articles in Historical Archaeology, Tennessee Archaeology, Southeastern Archaeology and Current Research in the Pleistocene, as well as two books Integrating Zooarchaeology and Paleoethnobotany (co-edited with Amber VanDerwarker) and Trends and Traditions in Southeastern Zooarchaeology (editor), a guest co-edited issue of Tennessee Archaeology, numerous chapters in edited volumes, and as author or co-author of over 30 technical reports.

I have been the recipient of several research grants and awards from the Royal Society of Edinburgh International Scholar Exchange Fellowship, the Charles H. Fairbanks Award (University of Florida), a Smithsonian Tropical Research Institute Fellowship, National Science Foundation, and the Tennessee Historical Commission. In addition to being active in research and teaching I hold, or have held, positions in the Tennessee Council for Professional Archaeology, Kentucky Organization of Professional Archaeologists, Southeastern Archaeology Conference, and Society for American Archaeology.

I consider myself a third generation southeastern zooarchaeologist. I began my zooarchaeology career in 1994 as a student of Dr. Rochelle Marrinan at Florida State University (FSU). Dr. Marrinan (or Dr. M as we all referred to her) was a student of Dr. Elizabeth Wing at the University of Florida (UF) in the 1970s. During my years at FSU (where I received both a B.A. and M.A. in Anthropology) Dr. M. mentored and taught me, and scores of other undergraduate and graduate students, the rigors of taxonomic identifications and zooarchaeological data analyses and interpretations, just as she was mentored and taught by Dr. Wing. During that first zooarchaeology course we students were assigned our very own faunal assemblage to analyze. The assemblage was excavated in the 70s at the Snow Beach Site, a Swift Creek Period shell midden. My thesis focused on the non-megafauna recovered from the Bolen level at the Page-Ladson site in Jefferson County.

In 1997, after receiving an M.A. in Anthropology at FSU, I moved south to Gainesville to begin work toward a doctorate in Anthropology, emphasis in Zooarchaeology, guided in part by Dr. Wing. While my actual dissertation focused on a site in Panama, I never strayed far from the Southeastern US. While in Panama I applied the field and lab methods I learned at FSU and UF to my PhD research of a Preceramic coastal shell midden. When analyzing the faunal assemblage for my dissertation I relied on the Zooarchaeology comparative collection and the expertise of Dr. Wing and Dr. Richard Cooke (Smithsonian Tropical Research Institute) to identify difficult specimens. During my time  at UF I worked at the Florida Museum of Natural History on several faunal assemblages from southeastern projects including: Aucilla River Prehistory Project (Vertebrate Paleontology Range), Everglades National Park Environmental Reconstruction (EA Range), and Snake Island Zooarchaeological Analysis (EA Range).

I am so pleased to once again be a part of the FSU community — I enjoy teaching and mentoring undergraduate and graduate students, and working with my very talented and supportive colleagues in the Department of Anthropology. I am excited about working on Woodland Period Maritime sites along Florida’s Gulf Coast in cooperation with a number of state and federal agencies and private organizations.