Recording Ireland’s early Christian monuments using aerial and terrestrial laser scanning Anthony Corns, Gary Devlin & Robert Shaw The Discovery Programme
May 15, 2015
Recording Ireland’s early Christian monuments using aerial and terrestrial laser scanning
Anthony Corns, Gary Devlin & Robert Shaw The Discovery Programme
• The Icons List for Ireland
• The Early Christian Sites
• Equipment
• Clonmacnoise
• Glendalough
• Skellig Michael
• Conclusions
Today’s Presentation
The ‘3D-ICONS’ of Ireland
Brú na Bóinne
Knowth
Newgrange
Clonmacnoise
Derry city walls
Dún Ailinne
Drombeg stone circle
Gallarus oratory
Glendalough
Hill of Tara
Loughcrew Cairn T
Navan Fort
Poulnabrone portal tomb
Rathcroghan
Skellig Michael
Stone Forts
An Grianan Ailigh
Cahergal
Dúcathair
Dún Aonghasa
Dún Eochla
Staigue
Clonmacnoise
Glendalough
Skellig Michael
The early Christian Sites
CAPTURE
• Monuments
• Artefacts
• Scanning
• Photography
• Aerial survey
MODEL
• Solids
• 3d pdf
• GML
DEPOSIT
• Repository
• Metadata
USE
• Europeana
• Education
• Tourism
• Conservation
Project pipeline
Equipment: Faro Focus 120
• Phase based laser scanner
• Distance accuracy up to ±2mm
• Range from 0.6m up to 120m
• Measurement rate up to 976,000 points/sec
• Small and compact: weighing just 5 kg
• Intensity & RGB
• Intuitive touchscreen display
• Integrated colour camera
• Photorealistic 3D colour scans with up to 70 megapixels
• Parallax-free colour overlay
Processing Path: Faro Focus
EXPORT FOR MODELLING
BENTLEY POINTOOLS SEGMENTATION CLEANING
FARO SCENE REGISTRATION GEO-REFERENCING
FARO FIELD DATA GATHERING
Equipment: Trimble VRSNOW
• Georeferencing to Irish National Grid
• Trimble 5800 dual frequency receiver
• Real Time Kinematic (RTK)
Horizontal ±10 mm + 1 ppm RMS
Vertical ±20 mm + 1 ppm RMS
• Trimble VRS Now: a subscription service
that provides instant access
to RTK corrections
Equipment: Artec EVA
• Hand held projected light scanner
• Light source: flash bulb (no laser)
• Up to 16 frames per second
• Data acquisition: up to 2 000 000 points/s
• 3D resolution, up to 0.5mm
• 3D point accuracy, up to 0.1mm
• 3D accuracy over 100cm, up to 0.03%
• Texture resolution 1.3mp
•Output formats OBJ, PTX, STL, WRML, ASCII, AOP,
CSV, PLY, E57
Processing Path: Artec EVA
EXPORT FOR MODELLING
Geomagic STUDIO 2012 (64 bit) CLEANING DECIMATION
Artec STUDIO 9 REGISTRATION APPLY TEXTURE
Artec STUDIO 9 FIELD DATA GATHERING
Clonmacnoise: Monastery
Clonmacnoise: TLS
PHASE 1 Cathedral & core buildings
• 35 separate scans
• Intensity and RGB
• VRS Now geo-referencing
• 2 days (April 15th – 16th 2013)
PHASE 2 complete monastic complex
37 separate scans
• Intensity & RGB
•Intensity and RGB
• VRS Now geo-referencing
• 2 days (July 9th – 10th 2013)
Over 1 billion points!
Clonmacnoise: Pointcloud
Clonmacnoise: Pointcloud
Clonmacnoise: Carved stones
Carved Slabs
6 proposed
6 completed 2013
High Crosses
3 proposed
Survey planned winter 2013/14
Clonmacnoise: Carved stones
Original
Deliverables:
Web GL
Surface
Wrap
3D scanning
Glendalough: Monastic City
• Project broken into
discrete sites in valley
• 12 individual
monuments to scan
• Faro Focus 120
• Completed in 8 days
Glendalough: planning
Glendalough: Point Cloud
Skellig Michael
Skellig Michael: Flimap lidar • Range < 300m
• Altitude 40 - 400m
• 3 X 150 kHz lasers
• Scanning Angle 60°
• Accuracy (absolute)
• Horizontal ±8 cm
• Vertical ±5 cm
• Accuracy (relative)
• Horizontal ± 5cm
• Vertical ±3cm
Skellig Michael: lidar model
Sensor: FliMAP 400
(Helicopter)
Survey area: 0.3km2
GSD: 12.5cm
x,y,z first return only
Skellig Michael: lidar visualisation
South Peak
Skellig Michael
10m
5m 100m
South Peak
Skellig Michael
Monastery
10m
5m 100m
Skellig Michael: lidar limitations
Skellig Michael: TLS
• Faro Focus 120
• 48 scans (3 sessions on site,
12 hours survey time )
• Closed loop traverses
• Over 500,000,000 points
• Intensity & RGB
• VRSNOW GPS control
• Registration / Georeferencing:
Faro Scene 4.8
• Visualisation / Interrogation:
Pointools Edit (v 1.5)
Skellig Michael: lidar plan
Skellig Michael: pointcloud
Skellig Michael: Data fusion?
Flimap lidar
Faro Focus, Terrestrial laser scan
DATA
FUSION?
Conclusions / Challenges
Conclusions
• data capture on course: completion June 2014
• lots of data cleaning required
• data re-use – state agencies very interested in scientific /
promotional value of data
Challenges
• meshing complex pointclouds
• complete the pipeline – MODEL – DEPOSIT - USE
• data fusion
www.discoveryprogramme.ie
More information:
http://3dicons-project.eu/
http://www.discoveryprogramme.ie/
Contact:-
Thanks to:-