English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The great barn at Harmondsworth near London Heathrow airport, United Kingdom (UK), was built in 1426–7 for the Bishop of\udWinchester. At 58 metres long and 11.4 metres wide, it is one of the largest ever known to have been built in the UK, and the largest\udintact medieval timber-framed barn in England. The barn is built almost entirely of oak, although the walls rest on a low masonry\udsill-wall. Internally the space is divided into a central "nave" with a lower aisle to each side, and is divided along its length into 12\udbays. There are three doorways on the east side. For an entirely timber-framed barn, the fabric is exceptionally well preserved. Even\udthe external weatherboarding may be partly original. Following years of neglect, however, there are a number of on-going structural\udand conservation problems, so in 2011 the barn was bought by English Heritage in order to allow these needs to be addressed. English\udHeritage is the government agency responsible for the historic sites and buildings in the care of the state of England and is also\udthe UK government's lead advisor on the built heritage.  \udAs one of the first steps in the conservation process the English Heritage Geospatial Imaging and Imaging & Visualisation teams undertook\uda four-day campaign of survey data collection. This took the form of laser scanning of the interior and exterior of the barn\udplus the acquisition of photography of the exterior elevations to be used with structure from motion (SFM) software. A comparison\udof the results of these complimentary yet potentially competing technologies will be given, as well as an evaluation of when they can\udbe successfully used together.  \udThis paper will describe the procedures and problems involved with collecting the survey data and its subsequent analysis. The laser\udscanning was undertaken using a FARO Focus 3D phase based instrument. Approximately 60 scans were acquired in order to provide\udas comprehensive as possible coverage given the site circumstances. A repeat visit following the clearance of artefacts and with\udthe benefit of access equipment was required to obtain complete coverage, especially for the top surfaces of the timber frame elements.\udInitial results from the laser scanning were extremely promising, with some historical events (e.g. a major fire at one end of\udthe structure) dramatically shown in the intensity data. Comprehensive photographic coverage of the exterior of the barn including\udthe roof was obtained using a Nikon D3X mounted on both a 6m telescopic pole and a conventional tripod. A repeat visit was required\udto address some exposure problems in shadow areas.  \udA unified control network for both sets of data was obtained through the use of a total station theodolite (TST) with reflectorless\udelectromagnetic distance measurement (REDM), incorporating a closed traverse as well as the acquisition of scanner and photogrammetric\udtargets. The control network therefore permits the direct comparison of the results from both survey methods (allowing\udfor systematic errors). A point cloud generated from the photography, using Agisoft Photoscan structure from motion software, was\udcompared with the registered laser scan points with a view to determining any systematic differences, although these were to a large\udextent ameliorated by the use of the dense control network.  \udThe resultant data also has potential downstream use within English Heritage for improving our understanding of Building Information\udModelling (BIM) as applied to heritage structures rather than new build, and thereby contributing to the formulation of elements\udof a BIM strategy for English Heritage.  \udThere are also a number of hand-measured survey drawings of the barn in existence. A quantitative as well as a qualitative comparison\udwas made with drawings generated from the laser scan data. In general the later drawings were more metrically accurate but exhibited\udless understanding of the construction techniques employed. A discussion of the reasons for this is also presented

the international archives of the photogrammetry, remote sensing and spatial information sciences/international archives of the photogrammetry, remote sensing and spatial information sciences

A COMPARISON OF LASER SCANNING AND STRUCTURE FROM MOTION AS APPLIED TO THE GREAT BARN AT HARMONDSWORTH, UK