0806514_digital building conservation_tls vs photogrammetry - doocot
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DIGITAL CONSERVATION: DOUGALSTON DOOCOT!Terrestrial Laser Scanning vs Photogrammetry
Peter McCready !08065141
PRESENTATION OUTLINE
Peter McCready !0806514
1. Project Overview 2. Deliverables 3. Study Area 4. Doocot - Interior and Exterior 5. Project Resources 6. Terrestrial Laser Scan 7. Photogrammetry 8. Comparison of Methodologies
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PROJECT OVERVIEW
Peter McCready !0806514
Provisional Project Title: Digital building conservation: a comparative study of Terrestrial Laser Scanning and Photogrammetry. A case study of the Dougalston Estate Doocot in Milngavie, Glasgow.
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• Interior and exterior Terrestrial Laser Scan (TLS) of the Doocot !
• Photogrammetry of a section of the Doocot !• Generate 3D models from TLS and Photogrammetry data !• Comparison of the two different methodologies !• Submission of a 3D model to the Royal Commission on the Ancient and
Historical Monuments of Scotland (RCAHMS) and provide model to local heritage and history groups
Intentions:
1. Interior and exterior 3D model of the Doocot from TLS (That will be submitted to RCAHMS) !
2. 3D model of a section of the Doocot from Photogrammetry !
3. Comparison of the two different methods and a recommendation !
4. Lessons learned and recommendations for a future project
Peter McCready !0806514
DELIVERABLES
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STUDY AREA
Doocot
Peter McCready !0806514
N
N
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DOOCOT
Peter McCready !0806514
ExteriorVisible Water Damage
Hardcast Removal?
Interior
Brick Degradation
Lantern Hole Covered
Ladder and Axle Removed from Roof and Ground Housings
Gaps in Roof Woodwork
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Peter McCready !0806514
PROJECT RESOURCES
EQUIPMENT OFFICE HARDWARE PROCESSING SOFTWARE
LEICA 1200 STATIC GNSS COMPUTER LEICA GEOOFFICE 8.1
LEICA SCANSTATION C10 LASER SCANNER EXTERNAL HARD DRIVE LEICA CYCLONE 8.1
LEICA HDS 6” TARGETS USB DRIVE AGISOFT PHOTOSCAN
DSLR CAMERA CLOUD COMPARE (Open Source)RTK GNSS AUTODESK 3DS MAX (Trial Version)
TRIPODS BLENDER (Open Source)
3m MEASURING TAPE (Instrument Heights)
WOODEN STATION PEGS
WAX PEN (To Mark Interior Station)
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1. Control network setup! - Static GNSS - Check with RTK GNSS
2. HDS 6” target scanning (BS & FS)!! - ! Adopting the Traverse Method!
3. Point cloud acquisition (Doocot Laser Scanning)!4. Image acquisition (TLS Photography)!5. Traverse to next station until complete!6. Data cleaning & modelling
Peter McCready !0806514
TLS PROCESS
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Image Source: http://eca.state.gov/
Peter McCready !0806514
TLS TRAVERSE
• 6-10 Exterior Scans (Currently Undecided) • 1-3 Interior Scans (Currently Undecided) • Station C used as Reference Point for Interior Traverse
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C
H
G
I
INTERIOR!TRAVERSEEXTERIOR TRAVERSE
1. Image capture!2. Inspect image-set!3. Photography processing - Structure From Motion (SFM)!
- Image alignment, camera calibration & camera positioning - Feature point detection - Feature monitoring
4. 3D point cloud generation!5. Building Mesh (Geometry)!6. Texturing
Peter McCready !0806514
PHOTOGRAMMETRY PROCESS
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Image Source: http://michot.julien.free.fr/
1. Methodology (equipment requirement, expense etc.)
2. Point Cloud Accuracy
3. Data Capture Time
4. Data Processing Time
Peter McCready !0806514
TLS vs PHOTOGRAMMETRY
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• Will add to the comparison criteria after further reading
Comparison Criteria:
Please Contact:!!Peter McCready - MSc Candidate [email protected]
FURTHER INFORMATION
Peter McCready !0806514
References:!!!GREAT BRITAIN. Peter McGowan Associates (2006) Survey of Historic Gardens and Designed Landscapes in East Dunbartonshire, East Dunbartonshire: East Dunbartonshire Council !UNITED STATES OF AMERICA. CALIFORNIA DEPARTMENT OF TRANSPORTATION. (2011) Caltrans Surveys Manual. State of California: Office of Land Surveys !Verhoeven, G. (2011) Taking Computer Vision Aloft - Archaeological Three-Dimensional Reconstructions from Aerial Photographs with PhotoScan, Wiley Online Library [Online] Archaeological Prospection 18 (1) p.67-73. Available from: http://onlinelibrary.wiley.com/doi/10.1002/arp.399/full [Accessed: 7th May 2015]
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THANK YOU!ANY QUESTIONS?