Skip to 0 minutes and 7 seconds The value of aerial reconnaissance has been understood by generations of archaeologists. But now new technologies and the platforms capable of carrying those technologies are being introduced. Today we are joined by Dr Karolina Fieber from Newcastle University’s Civil Engineering and Geosciences Department. We will be discussing how the University is currently using these resources in order to transform our understanding of Hadrian’s Wall. Much of Newcastle’s efforts in this direction are being developed through a project known as CHT2. Ian, what can you tell us about this project? CHT2 stands for Cultural Heritage Through Time, it’s an international project, four nations coordinated through our colleague Gabriele Guidi in Milan Polytechnic and Newcastle’s effort is focused on Hadrian’s Wall and modelling landscape change.
Skip to 0 minutes and 57 seconds What we are looking at is how we can bring a whole range of different data-sets, some for example, drawn up from laser scanning, others from traditional methods such as aerial photographic analysis, into the modelling of 4D landscapes. So the third dimension of course, height and space, but the fourth; actually looking at temporal change. Ian has mentioned laser scanning. Karolina, what can you tell us about how this works. Laser scanning uses short infrared pulses that are sent out by the sensor to the target surface. Precise measurement of the travel time between emitting the pulse and receiving the echo bounced off the target, facilitates calculation of the distance between them.
Skip to 1 minute and 45 seconds With known coordinates and orientation of the sensor we can compute the exact location of the target within laser footpath. In such a way we can obtain millions of points, a so called point cloud in a very short time. Those point clouds can be later visualised and post-processed to generate a continuous surface. Laser scanners are mounted on different platforms such as satellites, aircrafts, drones and there are also terrestrial laser scanners and devices mounted on vehicles and handheld devices. I also understand you use a process called structure from motion in order to model landscapes. How does that work and how does it compare to other methods?
Skip to 2 minutes and 35 seconds Structure from motion is the process of simultaneously estimating three-dimensional geometry of the scene, so therefore structure and camera pose therefore motion, from a series of overlapping offset images. This is achieved by finding and matching corresponding points in the image overlap area. In such a way that we also obtain point clouds that can later be post-processed in a similar fashion to laser scanning point clouds. The difference between the point clouds generated from those two methods is that laser scanning is capable of penetrating through the gaps in vegetation canopy and because of that it can provide information about the terrain surface hidden underneath trees. And what is new about the way that you are using this data within CHT2?
Skip to 3 minutes and 32 seconds We are looking at integrating heterogeneous information coming from different sources such as aerial and terrestrial photographs, laser scanning, geophysical data, nautical charts, historical maps, paintings and drawings into models of changing landscapes of heritage sites. In particular, we are focusing on the temporal aspects of the landscape change related to soil, costal and fluvial erosion and its impact on cultural heritage with implications for management of historic sites and with the benefit of interpretation for stakeholders. So Ian, what do you ultimately hope this project will achieve? I think essentially, what we are going to be looking at is something that allows us to understand better some of the risks to Hadrian’s Wall.
Skip to 4 minutes and 29 seconds It seems that many of these sites are going to be there forever, in reality environmental change is having an impact on many of the sites, particularly along the coast. So being able to model that change over recent time is very important but the same developments and methodology will also help us to better understand some of the longer term dynamics going back into the past and perhaps better understand the original form and character of those sites when they were first settled in the Roman period. Well thank you both very much for joining us today. Thank you Thank you
New perspectives from the air
We have seen already that aerial reconnaissance is an extremely valuable tool for archaeologists.
In recent years a range of new technologies and new platforms have become available. In this video Skylar Arbuthnot talks to Ian and Dr Karolina Fieber about harnessing these new opportunities to transform our understanding of Hadrian’s Wall.
Karolina provided some notes to accompany this interview which you will find in the Downloads section.
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