Digital Archaeology from the Air

This is a slightly altered and extended version of the Day of Archaeology post I wrote a little while ago; you can see the original post on the Day of Archaeology website.

 

Hi, I’m Helen. I’m actually a computer scientist rather than an archaeologist, working on a project called `HeritageTogether’, which is all about creating 3D models of prehistoric sites in Wales. The project is run jointly between archaeologists and computer scientists at Bangor, Aberystwyth and Manchester Metropolitan Universities – I work as a researcher in Aber.

The hexacopter we are using on the HeritageTogether project.

We are making the models using photographs of the site and a process called photogrammetry which matches up the features in photographs and can automatically create the model. While the project is mainly based on photographs contributed by the general public, we sometimes go out to survey some sites ourselves.

To help with our surveying, we have an Unmanned Aerial Vehicle (UAV) – a remotely controlled flying vehicle that carries a camera; a hexacopter (it has six rotors) to be specific.

Today, Andrew, Joe, Jonathan and I were visiting two sites on Anglesey in North Wales – the Lligwy burial chamber and Din Lligwy settlement near Moelfre. Two beautiful sites which are well worth visiting.


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Lligwy burial chamber was the first site we visited. It is a Neolithic tomb made up of eight upright stones supporting a huge capstone which is estimated to weigh at least 25 tonnes.

Lligwy Burial Chamber
Moelfre, Isle of Anglesey

Read more about this site:
Cadw (SAM: AN009)
Coflein (NPRN: 95532)

We flew the hexacopter above the burial chamber, getting a number of photos of the top of the capstone. Once we had done some aerial photography, we landed and photographed the site on foot.

Lligwy Burial Chamber from above!

Lligwy Burial Chamber is now in our gallery:

See the photographs →
See the 3D model →


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After we had finished photographing the burial chamber we went a little further down the road to reach the Din Lligwy settlement. The settlement is a group of circular and rectangular building from the Romano-British period, enclosed in a large outer wall.

Din Lligwy Settlement
Moelfre, Isle of Anglesey

Read more about this site:
Cadw (SAM: AN023)
Coflein (NPRN: 95532)

We flew above the site, first taking photographs then also capturing a video. We then took a large number of ground shots of the complex site.

Din Lligwy from above; Joe and I flying the hexacopter.

Din Lligwy Settlement is now in our gallery:

See the photographs →
See the 3D model →


So here are pictures of the two models we made from the surveys:

llig_bc_din_lligwy

 

Finally, here is the rather fantastic bit of video we managed to capture from above the Din Lligwy Settlement (all cut and tidied up by Andrew) – enjoy!

 

This post was originally published on the HeritageTogether website.

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Capturing Bryn Celli Ddu

Photographing the large mounds of burial chambers is a tricky business – being able to get high enough to make sure you can see the whole mound requires a bit of aerial camera work… Enter our aerial surveying platform (which we will tell you more about in an upcoming special blog post!), an Unmanned Aerial Vehicle (UAV) carrying a camera underneath. Being able to fly above the mound lets us take photographs like this one (you can see the rest of the photographs here):

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The other problem with photographing the mound is that the uniform texture of the grass makes it difficult for the computer to pick out good keypoints, which is why we have used some optical markers (the square sheets of paper) on top of the mound – these are just shapes that the software can use to match up the photographs.

We also got some video footage flying around the mound, which shows the site very nicely in context with the surrounding rural landscape.

The photographs were used to make a model of the mound. We also have photographs of the inside of the mound, which we are hoping to combine into a model of greater detail in the future.

 

This post was originally published on the HeritageTogether website.

Photography Workshop at Coetan Arthur

Coetan Arthur is a fantastic dolmen situated in Cefnamlwch on the Llŷn Peninsula. Seren and I met up with Jamie from the Llŷn Archaeology and History Society to visit the site and help our volunteers get started photographing sites!

Seren gave a great introductory talk on the site, and then we all set about photographing the site together. The photographs taken at this workshop will be used in the digital photogrammetry workshop we will be running with Llŷn Archaeology and History Society on the 16th of July. If you’re interested in having a hands-on experience with processing some photogrammetry data, you can sign up for the workshop here!

Seren's Introduction

Photographing the Dolmen

Thanks to everyone who helped us to photograph it – many of the photographs are already up on the gallery!

 

This post was originally published on the HeritageTogether website.

Open Day Fun at Barclodiad y Gawres

On a blazing hot saturday, the team headed out to Barclodiad y Gawres – a stunning chambered tomb on the coast of Anglesey – for an open day organised in collaboration with Cadw. Since an incident of vandalism some years back, access to the inside of the tomb has been restricted (although access is available on request, see more info on the Cadw website), but during the open day visitors were offered guided tours inside with the wonderful Rhys Mwyn. During the day, Lee flew above the mound and took some great photographs (you can see the whole album here), we made another rock art mural with the help of some wonderfully artistic kids, and spoke to lots of lovely and enthusiastic people about the site.

Rock art inside Barclodiad y Gawres

Barclodiad y Gawres

Using these photographs, we were able to create a model of the mound. We will be heading back to survey the inside sometime soon, as it will require careful lighting to make sure the rock art is photographed at it’s best – if you had a look inside, you will know just how dark it is! Thanks to everyone who came out and visited the site, we hope you had as fantastic a day as we did!

 

This post was originally published on the HeritageTogether website.

Celebrating the Solstice at Bryn Celli Ddu

On the 21st of June, we joined Cadw at Bryn Celli Ddu for a celebration of all things Neolithic! Visitors got the chance to see flint-knapping demonstrations, learn about aerial photography, make embossed badges and much more.

Lee shot this video from above the site during the day, which is a great watch!

We also had special permission to visit a natural outcrop in a neighbouring field (which is private land, so please don’t visit without permission!) on which up to 28 cup marks were discovered in 2005 (you can see some in the left image). Towards the end of the day, the sun treated us to a fanstastic view of the rock art on the stone just outside the burial chamber.

Cup Marks

Rock Art at Bryn Celli Ddu

 

This post was originally published on the HeritageTogether website.

Exploring Melindwr and Blaenrheidol in Ceredigion

Although I’ve been working in Aberystwyth University since the start of February, finishing work on my PhD had consumed every spare moment I had until now. Finally, I had some time this weekend to go out exploring around my new home!

To make sure I could see a few sites, I spent some time looking at my OS map and the Coflein map, trying to find a couple of areas where sites were clustered. I wasn’t very confident about heading out on my own in a totally new mountain range, and was a bit worried I might get lost, so my parents joined me on my little trip out. Together, we set off exploring together on a rather wet Saturday morning.

Panorama from the road near Disgwylfa Fach.

We started at Ponterwyd, and drove north into the mountains towards Disgwylfa Fach. We spotted one of the stones we were looking for on the side of Disgwylfa Fach and found a nearby place to park the car. From the road, the stone didn’t look very far, but the ground looked a little rough so my dad and I grabbed some walking poles and set off. The walking poles turned out to be very useful, as the ‘rough ground’ was, in fact, thick, knee-high grass with boggy ground below.

The OS map marked a single standing stone in the area, but when we got to the top, we found a second stone – a large white quartz boulder – with a row of small stones coming from it. We decided this couldn’t possibly be a natural feature, and decided to photograph it. Doing some research on Coflein later, it turned out we had found the Disgwylfa Fach stone row. The Two largest stones were quite prominent, but the other 5 were very small and barely stuck out from the top of the grass; I am not sure the smaller stones will be visible enough for them to feature in the 3D model. Or I may just have to head back and get some more photos!

As we headed off towards the Disgwylfa Fach standing stone, the skies opened and it began to pour with rain. My dad kindly held up an umbrella for me while I photographed the stone (fortunately, the wind wasn’t too bad). After about 5 minutes the rain suddenly stopped, so we took the opportunity to get back to the car in the dry.

Climbing Disgwylfa Fach

Disgwylfa Fach Stone Row

Disgwylfa Fach Standing Stone

Panorama taken near the Buwch a'r Llo standing stone pair.
Panorama taken near the Buwch a’r Llo standing stone pair (and me in the process of photographing them).

Heading off further down the road, we came to the standing stone pair called Y Buwch a’r Llo (the Cow and Calf), which was much easier to get to than the Disgwylfa Fach stones!

Just a couple of minutes’ walk down the road we found Maen Tarw (the Bull Stone); also a nice, easy find. The stone is broken, and although no explanation is offered in the Coflein entry for the stone itself, there may be a reference to it in the entry for the Buwch and Llo pair:

“Third stone to west in forestry struck by forestry machine at some point in 20th century and broken in-situ.”

 

Garrig Hir

After parking the car near Llyn Pendam, we followed the Devil’s Bridge to Borth path, until we spotted Garrig Hir in a field near a small cottage. Though we could see it from the footpath, we weren’t entirely sure on public access rights, and so we did not attempt to get any closer. I plan to look into this, and hopefully will head back to the site if it is accessible – looks like it would make a nice model!

We set off to look for some other potential sites, but by now the weather had taken a particularly bad turn, so we decided to stay in the car and scout them out for next time. We spotted the Garn Lwyd stone and the Hirnant kerbed cairn, but given that they were both behind fences, I plan to check whether there is public access before trying to visit them.

Garn Lwyd

Hirnant Kerbed Cairn

 

This post was originally published on the HeritageTogether website.

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