A trip to York, and Lancashire, and London…

It has taken me a while to post this, but the last month has been really busy. So, recap of the past 3 weeks:

Week 1, a trip to York (and Lancashire, and London) on an intern exchange programme, hosted by Historic England’s Geospatial Imaging team. Li (who has already blogged about this -check out her blog here) is the Geospatial team’s CIfA placement and will be joining us this following week in Edinburgh (and Inverness, and Fortrose, and Elgin) for the second half of our exchange.

My week with Historic England was busy, packed with site visits (amazing Rievaulx Abbey and Mount Grace Priory), an SfM photogrammetry session at English Heritage’s archaeology store in Helmsley, a laser scanning survey of Bellmanpark lime kilns in Clitheroe, and finally a day trip to the Natural History Museum in London. I had the chance to participate in field work as part of the team, both in Helmsley (photographing a 19th century curiosity for SfM photogrammetry with Li), and Clitheroe (survey for structural monitoring of the historic lime kilns using P40 laser scanner and TST ). Having experience with the techniques and equipment from my own internship in Digital Documentation, it was great to see how the Geospatial team use the same technology to tackle similar problems. I’ve left York full of new ideas and keen to try them out in future projects.

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Which brings me to the end of the week, when I was so lucky to be invited to Historic England’s visit to the Natural History Museum Research Labs in London. We spent the day touring the Imaging and Analysis labs and hearing about the amazing research that takes place there. I could probably write an entire post about this, but for now just 2 words (or 5): SEM photogrammetry. Dramatic pause. Also, confocal microscopy, CT scanning, 3D modelling. It was an absolutely fantastic experience and a perfect ending to my week with Historic England.

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During the last 2 weeks, most of my time has been spent working on a BIM model of the Palace at Edinburgh Castle. This subject definitely deserves its own post, so stay tuned. The building has undergone many phases of development and alterations, which have resulted in an extremely complex structure – geometrically, but also functionally. Creating a BIM model for this type of building is not straightforward, even with the advantage of having a complete point cloud as a basis for modelling.

Having had the opportunity to follow this project all the way from laser scanning on site to data processing and registration and now to modelling in Revit, I can see that creating a BIM model for the Palace will be a great asset for in-depth understanding of the structure, the way the building works, and the way it has changed over time. The model is being developed in-house by HES and requires the coordination of different teams and disciplines. Eventually, when both structural and M&E information is added to the architectural model, we will have a complete picture of this building from a single source – probably for the first time ever. More on the Palace BIM project to follow within the next few weeks.

The Palace block, Edinburgh Castle. Screenshot of the point cloud in Recap.

 

Edinburgh Castle Palace Scan2BIM

March was a very busy month for the Digital Documentation team. Much of our time has been spent laser scanning the Palace block at Edinburgh Castle for a scan-to-BIM case study by Historic Environment Scotland. The idea is to create an BIM or AIM (asset information model) of the Palace block to be used for the subsequent management of various aspects of the building’s function.

Laser scanning is the primary method of survey for the building fabric (architectural elements), but it will be supplemented by additional surveys. The laser scanning survey is guided by the Asset Information Requirements document, which specifies areas of interest/priority and required levels of detail per category. The goal is to achieve 100% coverage of both exterior and interior spaces.

According to the AIR document, some of the least “glamorous” areas of the building, such as boiler rooms, electrical cupboards, switch rooms, and attic spaces have a higher priority for the model than some of the high-profile exhibition areas for example. This means that a lot of our time on site has been spent crouching inside tiny cupboards and boiler rooms surrounded by pipes and cables. These areas tend to be confined spaces full of equipment, difficult to navigate (or even to set up the scanner) and usually need a lot of scans to get good coverage and avoid shadows or data voids. Although we do not have to scan every last surface inside a boiler room, the AIR document makes it clear that at least the general dimensions and position of all equipment will need to be visible in the resulting point cloud.

In this project, multiple scanners have been used. The Leica P40 produces clean, crisp data with considerably less noise over great distances, but is very difficult (or impossible) to set up inside any of those tight cramped spaces. Therefore, all the cupboards, boiler rooms, switch rooms, etc were scanned with a Faro Focus 3D, which has a much shorter range and produces noisy data, but is significantly smaller, a lot lighter, and can easily fit inside any of those spaces. The same scanner was used in the attics, which were accessible through a folding ladder and generally very tight spaces, difficult to navigate when carrying any sort of equipment. Using the Faro proved very successful in those areas (on a photographic tripod or sitting directly on the floor).

Laser scanning an attic at Edinburgh Castle Palace with a Faro Focus 3D. Ghostbusters uniform to be worn at all times, as per the risk assessment report. 

Registration of the data has been progressing along with the field work. More on that to follow very soon…