Photogrammetry… seeing our units in 3D!
Most archaeology happens after the digging is over, and Heritage West’s work is no different! Since the close of excavations last November, the team has been focused on analyzing, interpreting, and documenting the finds from our four excavation areas at the Community Education Center in the North American Archaeology Lab at Penn. You can read lots of fun statistics about what we found in these early phases of analysis here. The success of our excavations and the fantastic effort on the part of our students and community volunteers in the lab last year means that we can keep being productive during the next phases of the project. Stay tuned for updates on more ways to get involved!
Now for an update on what we’ve been up to this fall, from Graduate Research Assistant Arielle Hardy.
Archaeology is inherently a destructive practice—once you dig the dirt out of the unit, you can never put it back in the same exact way—so ongoing documentation is a critical step in preserving the records of our excavation. Since our trenches were reburied (or “backfilled” in archaeology-lingo) when digging closed in November 2023, one of the first things we wanted to do was create a record of what they looked like at the end of the season. As we continue to process finds, this will help us understand where exactly objects were found in the ground, and reconstruct the process and timeline (or “phasing,” to use another archaeological term) of certain human actions that we saw while excavating… from the demolition of the homes in the 1960s, to the throwing away of garbage in the privy by the school in the 1930s and by the household on 35th St. back to the 1870s!
One of the best tools we have for this type of documentation is called photogrammetry. Photogrammetry is an archaeological technique that uses two-dimensional photographs—taken with a normal camera—to create three-dimensional digital models of objects and environments. By taking pictures from multiple angles, you can digitally stitch together a 3D image of almost anything, from bottles, to archaeological trenches, to people!
In these photos you see project director Megan Kassabaum and student Nikki Meyer taking photos of our excavation units during the last week of fieldwork in November 2023. In the background you can see various other students, staff, and volunteers helping to provide shade for the photographs.
Several computer programs help to build these types of models, and some favorites for our team members are Metashape and RealityCapture, but many phone apps (for newer iOS and Android devices) are capable of producing low resolution models too. Digital rendering is an important non-destructive method which helps preserve cultural heritage and communicate archaeological findings, making this material remotely accessible to local communities, cultural stakeholders, students, and researchers.
This fall, our team has been using the photographs taken of our four units at the end of excavation to build these digital models. We will be using them in our object documentation and analysis over the coming months, but the best part is they are publicly accessible too! We encourage you to check them out yourself by clicking on each of the four models below. (You can also find them in a bigger format on Sketchfab by searching “HeritageWestPHL”). Keep a lookout for additional models of finds that we will be uploading there throughout the spring!