Laser Scanning for Heritage Conservation – Bagan, Myanmar
The more than 2800 Buddhist temples and pagodas of the world renowned heritage site of Bagan, in Myanmar, erected between the 9th and 13th century, are distributed over an area of 10 by 10 km, making the site the densest concentration of religious monuments worldwide. Earthquakes have threatened and damaged the structures of Bagan over the past centuries but especially severe destruction was caused when an earthquake of magnitude 6.8 struck on the 24 August 2016. This time more than 100 monuments were damaged or partially destroyed with some reports claiming numbers close to 200. Reconstruction interventions are presently underway and there is also an ongoing initiative to apply for UNESCO world heritage status for Bagan, which will hopefully add further impetus to the conservation efforts in Bagan.
The Zamani Project from of the University Cape Town has spatially documented heritage sites with the objective of providing data which can assist with the planning and execution of restoration and conservation interventions. Among these were the rock-churches of Lalibela, the Palace Museum in Zanzibar, the pyramids of Meroe in Sudan and the Yemrehanna Kristos Cave-church in Ethiopia. It has been the policy of the Zamani group over the past twelve years to document holistically and go beyond the mere creation of point clouds and produce meshed and if possible textured models as well as a site GIS, panorama tours, and plans and elevations and ortho images. The experience of the Zamani teams in encounters with conservators and architects has frequently been a first very positive response to the textured model followed by a somewhat deflated “what can we do with the data?”. Point clouds are useful for building dimension measurements but this is often the only and full extent of their usefulness. The recent development of BIM software with the ability to import point clouds into CAD software seems to have improved this situation significantly. However, the Zamani team experienced the most positive response when providing, in addition to meshed and textured 3D models, ortho images of faces and inside walls generated from these models. These proved most useful to architects and conservators and added substantial value to the deliverables.
When hearing about the earthquake the Zamani project offered its assistance with the documentation of damages monuments and the group traveled to Bagan in March 2017 to record the Sula-mani-gu-hpaya temple.
The fieldwork took place over 7 days during which time 485 laser scans were acquired with two Z+F 5010 laser scanners. Numerous differential GNSS measurements were taken distributed over the entire temple at various elevations to quality-check the laser scan model, confirm the accuracy of the laser scan registration, and geo-reference the model and associated GIS. A DJI Phantom 4 was employed to capture vertical and oblique aerial photography to texture the model, to generate the photo realistic ortho-photo .
During the fieldwork the team were joined by members from the Department of Antiquities, who were trained in the use of the laser scanning equipment and the acquisition software.
Additionally 360 degree panoramas were taken of the site.
The result was a complete 3D computer model of the entire temple, inside and out. This model is textured (images taken from drone and terrestrial draped over the model).
The Zamani will return in September to document further monuments in Bagan. The September campaign will be funded by the Gerda Henkel Foundation, Germany. Zamani has not been able to secure funding for much needed further field campaigns
The Zamani Research Group comprises of the principal Investigator Heinz Ruther, and team members Stephen Wessels, Ralph Schroeder and Roshan Bhurtha, They were joined by former Zamani team member Christoph Held who is now an application engineer at Z+F in Germany.
Prof. (em) Heinz Ruther
Principal Investigator “African Cultural Heritage Sites and Landscapes” project
Division of Geomatics (APG)
University of Cape Town
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