3D metric survey for spaces, benefits for archaeology, industry and engineering. Ancient roots and current developments.
Image: 3D coloured laser scan of the Flaxman Gallery, UCL Art Museum. Laser scanner: Faro Photon 120. Dietmar Backes. 2009.
3D metric survey for spaces, benefits for archaeology, industry and engineering. Ancient roots and current developments.
Image: 3D coloured laser scan of the Flaxman Gallery, UCL Art Museum. Laser scanner: Faro Photon 120. Dietmar Backes. 2009.
The measurement of the space around us has been practiced since Ancient Egypt.
Mona Hess
Reseach Assistant for 3D imaging in cultural heritage, UCL Museums and Public Engagement, UCL CEGE
Image: Flinders Petrie surveying in Tell Fara in 1929.
The measurement of the space around us has been practiced for a long time. 3D metric survey for spaces are used in engineering, industry, architecture and archaeology.
The surveyor had an important role in Ancient Egyptians to surveyed the fields for a fair distribution of arable land around the Nile after flooding, for building construction. Tools like levelling and orientation have been used, and are still practiced today.
For accurately measuring and excavating in Ancient Egypt, Sir Flinders Petrie, also used known mathematics and surveying kit of the time. He had been taught surveying since his earliest youth by his father William, a civil engineer and professional surveyor.
Photogrammetry as a means of metrically surveying and monitoring buildings has been around since the 19th century stemming from developments in photography and improved technology of glass plates and gelatine layers. A good shot had to be planned as equipment was expensive and produced excellent photographs that are still valuable today for building preservation.
The recording of the space around us today is now done with high-tech kit, capturing millions of points and using laser technology. Totalstations are programmed to monitor constructions in a set routine without operator. Building Information Management integrates high-accuracy 3D recording with management of buildings for a better and sustainable use of our built environment.
Digital documentation today allows to document the status of a historic building, an archaeological site, or even a forensic site to be documented in the state of a moment in time. Monitoring and comparison of damages or movement is now possible with great traceability and accuracy.
3D measurement of our surrounding is increasingly available to everyone through affordable low-cost infrared metric sensors and free-ware software to recostruct interiours from photography. Digital documentation is now going also beyond our earth surface, with 3Dmapping of Mars.
Multimedia content
Contributor: John Hindmarch
Image: 3D coloured point cloud of the laser scan in the Shipping Gallery, Science Museum, Scanlab
The Shipping Gallery at the Science Museum, London, was its largest gallery in the museum and largely unchanged since 1950’s. When, after more than 60 years of service, the Science Museum decided to decommission their venerable old Shipping Gallery, they decided something more than the usual photographic campaign was needed to preserve and commemorate their largest and oldest exhibition.
They chose to record the entire space using terrestrial laser scanning, and approached Scanlab – a company formed by two UCL alumni, and current student John Hindmarch, to undertake the project. Locked in the museum for five long nights, the team used used a pair of scanners to capture 275 individual scans, creating 256Gb of data consisting of well over a billion precisely measured and individually coloured points. From the resulting point cloud, a seven minute video 'fly-through' complete with narration from the curator was recorded, which when hosted on the Museum's website will allow visitors to experience the Shipping Gallery long after it has gone, preserving and archiving the exhibition and prolonging the gallery's legacy way beyond its physical installation.
See also:
Contributors: Ali Hossininaveh Ahmadabadian, Ben Seargent
A fully automatic process for 3D surface measurement and reconstruction using stereo photogrammetry poses difficulties where the approximate geometry of the object surface is unknown. Whilst appropriate information, such as a design CAD model may be available for some objects, without prior knowledge planning through photogrammetric network design cannot take place and captured data are likely to be incomplete or inaccurate due to poor camera positioning and pointing.
Recent developments in real-time 3D reconstruction using low cost depth cameras allow for the rapid generation of an approximate object shape capable of paving the way for development of a fully automated system. Low quality surface models can be quickly acquired and used within the photogrammetric network design process the output from which are a list of positions and orientations (postures) at which the stereo imaging sensors should be placed to accurately reconstruct the whole object. To fully automate 3D reconstruction placement of the sensors can then be carried out mechanically using a robotic system.
PhD students at UCL have developed a system for accurate 3D digitization of complex objects using this approach. This system uses a Primesense Sensor utilising the Kinect fusion technique to generate an initial 3D model. This model is processed by a state-of-the art software package for Imaging Network Design (IND) [1] to specify ideal camera postures. A 6-degree of freedom robot (INDRo) [2] is then used to place two u-eye cameras and a digital SLR camera in the designed postures. The images captured are then processed with a novel method called photogrammetric multi-view stereo [3] to generate an accurate and complete point cloud.
More information in the following scientific papers:
Contributors: Charlie Thomson, Dietmar Backes
UCL Civil, Environmental and Geomatic Engineering (CEGE) [link to CEGE website] started the Green Building Information Model (Green BIM) project in 2012 to create full digital documentation of a non-domestic listed building that could aid facilities management especially with regards to sustainability issues.
The work focuses on the Chadwick Building, a Grade 1 listed building and home to the CEGE Department. The building was largely built in the late Victorian period, around 1892, with the exception of a tower that was added in the mid-1980s. The overall exterior facades of the Chadwick Building from both phases of construction mirror the Classical style of the main UCL Portico Building which was designed and built in the 1820s by William Wilkins; an architect who is perhaps more famous for the design of the National Gallery in London’s Trafalgar Square a decade later.
Over the years the interior has been the subject of many changes due to modernisation and alteration of research activities that the building has had to support. This retrofit work has included the piecemeal addition of a full basement level and several mezzanine floors. Due to this existing documentation is poor or non-existent.
For the first phase of GreenBIM, a digital model of the building has been created in Autodesk’s modelling package Revit, derived from terrestrial laser scanning data, in order to investigate and improve sustainability issues related with the building. In the long term the goal is to enhance the parametric model into a full BIM with semantic information including thermal imagery, building services data, CFD simulation and more.
In April 2013 this project’s contribution to a more sustainable University was recognised through the winning of the Office Depot Gold Award.
More information about BIM:
Contributors: Ahmad Baik, Jan Boehm
Jeddah is one of most important cities in the Kingdom of Saudi Arabia; it has a long history and there are many historic buildings that were built more than 300 years ago. The major issues that face Jeddah today are how the government can preserve and save them from the risk of collapse and erosion by natural and human factors, and disasters such as fires. The municipality of Old Jeddah City decided to preserve and develop this area.
Geospatial technologies applied for this task are Terrestrial Laser Scanning "TLS", aremote sensing, Global Position System "GPS" and architectural photogrammetry. These data sources will be used as input to the Jeddah Historical Building Information Modeling "JHBIM" for analysis. This approach will be digitally represented as a shared knowledge resource for the physical and functional characteristics of the historical building facilities in old Jeddah. The historical BIM will enable decision making about maintenance of historical structures. Furthermore, 3D models from JHBIM can enable remote reviewing of the interior and the exterior with even better understanding than 2D plans and section drawings. Moreover, we can save time "4 D", cost "5 D" and represent reality in a few hours and more reliably than before. Furthermore, the outcome data can be used for a number of applications over time, as needed.
The results will be of relevance to a wide variety of disciplines ranging from engineering, architectural and urban science to geospatial science. In particular, Old Jeddah, Saudi commission for tourism and antiquities, research institutes and Archaeologists will benefit from the findings and recommendations, in terms of operational decisions and building up knowledge about old Jeddah.
More information:
Contributor: Anita Soni.
This research looks at monitoring in a railway environment, with a particular focus on the potential of non-contact measurement techniques for monitoring. These might include methods such as terrestrial laser scanning (TLS) and photogrammetry. Currently, typical railway monitoring activities involve direct contact through the placement of targets (e.g. prisms) or sensors onto the structures being monitored. Technologies such as laser scanning or photogrammetry could deliver a ‘targetless’ solution as well as providing continuous surface measurement information of railway infrastructure.
The test site is the London Bridge Station development project. As part of the TLP, Key Output 2 (which runs from 2012-2018) involves a major redevelopment of London Bridge Station. Due to the planned construction work, many typical railway infrastructures are required to be monitored continuously throughout the project, in particular the railway track and arches. This has provided an ideal opportunity for setting up some of the test sites.
One of the aims of this site is to explore a fully “contactless” approach to monitoring of the tracks avoiding targets and therefore issues such as target disturbance and spurious movement reporting. The aim is to revisit a particular section of track and scan it at regular intervals over the year. The methods of producing models and the ability to extract relevant track geometry for monitoring purposes will be explored.
More information:
Contributor: Jan Boehm
IQmulus will leverage the information hidden in large heterogeneous geospatial data sets and make them a practical choice to support reliable decision making Nowadays, new data acquisition techniques are emerging and are providing fast and efficient means for multidimensional spatial data collection. Airborne LIDAR surveys, SAR satellites, stereophotogrammetry and mobile mapping systems are increasingly used for the digital reconstruction of environment. All these systems provide point clouds, often enriched with other sensor data such as return beam intensity, colour information or multispectral information, providing extremely high volumes of raw data. These volumes increase significantly faster than computing speeds – LIDAR acquisition speed has increased by a factor of 100 to over a 1 million points per second in just four years. While the growth of these data sets is not as fast as with point cloud data, there exists a giant stockpile of such data which cannot be fully used due to its size. With each acquisition approach, lots of data are collected, but each in their way, thereby producing highly heterogeneous data sets which require harmonization and integration before being really useful.
Improving methods to process and visually analyse this massive amount of geospatial data, including user generated one, is crucial to increase the efficiency of organisations and better management of societal challenges through more timely and better decision making. IQmulus aims at the development and integration of an infrastructure and platform that will support critical decision-making processing in geospatial applications.
IQmulus, a EU project(FP7-ICT-2011-318787) is a 4-year Integrating Project (IP) in the area of Intelligent Information Management within ICT 2011.4.4 Challenge 4: Technologies for Digital Content and Languages. IQmulus started on November 1, 2012, and will finish October 31, 2016.
IQmulus, a EU project(FP7-ICT-2011-318787) is a 4-year Integrating Project (IP) in the area of Intelligent Information Management within ICT 2011.4.4 Challenge 4: Technologies for Digital Content and Languages. IQmulus started on November 1, 2012, and will finish October 31, 2016.
More information:
Contributors: Suzie Green, Kieran Baxter
The image shows a 3D Model from the Hill forts of Fife and Angus in Catherthuns in Scottland. The archaeological landscape was modelled by Structure from Motion.
This research produced unique views of hill forts spanning from East Lomond hill above Falkland in Fife, to the Caterthuns nearby Bechin in Angus. Often passed-by but sometimes difficult to appreciate from the ground, these prehistoric banked enclosures are intriguing because of their form and longevity. The 3D models were created by using high and low altitude aerial photography along with state-of-the-art digital imaging techniques, structure from motion. This research was completed in collaboration with Historic Scottland.
Structure from Motion can be used for the archaeological investigation of landscapes and built structures. It allows for recording of the position and colour of surface points at the same time, which provides a direct link between colour variation (related to crop marks) and form to give an understanding of subsurface features. The use of a kite or unmanned aerial vehicle (UAV) can allow coverage of a large area in high resolution, allowing earthworks to be traced across the landscape. When used as part of an archaeological excavation, its simplicity, low-cost, high coverage and speed of recording, allows 3d recording of individual contexts in an archaeological excavation the data can be analysed in ways that are simply not be possible with 2d records. Similarly, the speed at which data can be gathered makes this a potentially important tool for the recording of underwater archaeology.
The low cost and easy acquisition makes this an important means of recording our heritage, and could make a significant contribution to, for example, Historic Environment Records, where cost is a significant consideration. The amount of detail that can be captured makes this an ideal way of recording features that could be damaged or destroyed, such as fragile wooden objects, landscapes that are to be developed, or stratigraphic layers that must be removed.
The recording of surface colour as well as form by structure from motion can be used to create the kinds of high resolution photo-realistic 3D models that are popular and powerful tools for disseminating archaeological ideas to the public.
See also: