Sun, Scanning and Skara Brae

As some of you will know I embarked on a last-minute adventure to Orkney last weekend with the C10 laser scanner. Despite a day of panicked planning, booking ferries and arranging site access on Wednesday – which resulted in higher than average blood pressure and about 3 hours of stress-induced hiccups – on Thursday the C10 and I were Megabussing it up the A9…

In Inverness I acquired a car and a travelling companion in the form of Kyla Finlay, long-suffering friend and my hired muscle to help me haul equipment on the trip. The journey to Thurso to catch the 1pm ferry on Friday was lovely and sunny and great fun, in spite of my insistence on waking up at 6am “just to be on the safe side” and my infamous old lady driving, “I know that tractor’s only going at 15 miles an hour, but I’m sure he’ll turn off the road soon, there’s no point in overtaking just yet right??”. Inevitably we arrived at the ferry nearly 2 and a half hours before it was due to sail…and it still took Kyla a good 10 minutes to convince me it was safe to undo my seatbelt and turn off the engine!

Having managed to drive the car on and off the ferry without ending up in the water or rear-ending a lorry (hey, arriving two hours early gave me a lot of time to mull over the various embarrassing scenarios which could occur!) we arrived in Stromness in one piece and made tracks for Skara Brae.

The visitor services staff were expecting us and were really accommodating, leaving us instructions on how to shut down and lock up the replica house when we had finished scanning that evening. We set up the scanner to record the outside of the house first since the weather was relatively calm and dry, before heading inside to scan the corridors and ‘living quarters’.

The C10 laser scanner working away in the interior of the replica house.

Being in charge of my own little scanning project was great, it really gave me a more balanced perspective of the whole process  as I began to consider the positioning of each scan station in terms of ease of processing when I returned to process and model the data in Glasgow. Issues of perceived objectivity always seem to arise when discussing laser scanning and certainly I was aware of the choices I was making as I worked. Because everything in the house interior was relatively close range, I decided it was best to set the C10 scanning at low resolution and try to take scans at varying heights with and without the tripod throughout the space to minimise holes in the data from areas the scanner couldn’t see.

Although what the scanner records is highly accurate, when you come to process the point cloud data into a solid mesh back in the computer lab, your model will only be as objective as your choice of scanning stations. It’s not just a case of ‘hit a button and wait’, choosing where to place the scanner within the space is an art to be mastered!

The next day was spent gallivanting around to various archaeological sites on the mainland, including Tomb of the Eagles, which we had all to ourselves – giving us time to perfect the high-speed ‘crawl and leap’ entrance and exit to the tomb on the famous skateboard! On Sunday we returned to Skara Brae to take reference photos inside the ruin of house number 7, which is closed off to the public and protected under a large roof.

Exploring House 7.

Being allowed to crawl down the passageways and explore the fragile house was without doubt one of the highlights of my archaeological career so far! Within the structure I gained a much clearer sense of the space, and was quite surprised at how spacious the house felt, especially after crawling on hands and knees through the tiny doorway. It perhaps sounds strange to say that the house felt quite cozy. There is something quite homely and practical about the layout, with stone blocks arranged round the fire like benches and ample storage in all the spaces built into the walls…but of course House 7 is a bit of an exception to the rule at Skara Brae given that it can only be locked from the outside and considering that there were burials under the floor. With this in mind I tried to remain wary of assuming too much about the function and use of the structure.

Crawling through the passages at Skara Brae.

I’m working on processing the data just now, so in between that and planning for St Kilda next week I’ll try to get around to posting some animations of the point clouds.

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One comment

  1. Jackie Petty · · Reply

    Hi Alice

    Have just read some of your blog and its really interesting, you certainly enjoy it as your words just flow in describing what you are doing. We have someone in the family who is clever as well as lovely. Well done “honourary auntie Jackie” xxxxxxx

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