New digital photogrammetry technology has changed rock face mapping. Daniel Hall writes for Australian Mining
Mapping rock mass structures is no longer a laborious and unsafe practice, thanks to CSIRO’s new rock mass mapping technology, Sirovision.
Traditional photogrammetry equipment required operators to have a sound knowledge of photogrammetry hardware and data processing, and required engineers and geoscientists to put themselves in front of unsafe rock mass.
CSIRO’s new digital photogrammetry technology, Sirovision, is making data collection, processing and analysis of rock face imaging cheaper and safer, CSIRO Exploration and Mining scientist George Poropat told Australian Mining.
CSIRO Exploration and Mining scientists Andrew Beitz, George Poropat, Wayne Robertson and Philip Soole are responsible for the research and development of the new technology.
The Sirovision technology uses stereo image pairs obtained with digital SLR cameras to capture separate images of the rock face.
After the cameras capture an image of the desired rock face, spatial data is registered in a co-ordinate system as 3D data points.
The data points are integrated with the visual data acquired by the cameras to produce a ‘true’ 3D image.
The image can then be analysed and assist in identifying geological units and rock structure.
Sirovision’s 3D digital images can be accessed by staff using commonly available computer systems and enables the user to access information and analyse rock mass structures over extended volumes.
Traditional mapping techniques that can provide comparably accurate structural data have a limited range and require personnel to access the rock face directly.
Sirovision can achieve spatial measurement resolution of the order of 1 in 10,000, or 1cm at 100m Poropat told Australian Mining.
The technology can also produce good results up to a kilometre from the surface of the desired rock face, meaning safer conditions for those operating the rock face mapping hardware, he said Mining consultant Paul Maconochie recently used Sirovision to map the entire Ok Tedi pit in PNG.
“Over of two months we identified more than 4000 structures,” Maconochie said.
“In the past some parts of the mine would have been impossible to map and analyse. “Fifteen years ago it would have taken three full-time people a year to do what we did with two full-time people in a period of three months.
“Mining companies are using the technology more as people recognise the value it brings to their business.” George Poropat told Australian Mining that previous rock face mapping technology forced geological surveyors into dangerous places.
“Geologists had to go right up to the rock face, which is a very dangerous place to be with rocks potentially falling on them,” he said.
The technology also reduces the time geologists spend at the face and allows them to spend more time reviewing and interpreting data.
Geologists may also assess the location of geological units that have previously been difficult or impossible to map, and geotechnical engineers can analyse joint sets without losing time on site.
“The time of geologists and surveyors is better spent doing what they are trained to do,” CSIRO Exploration and Mining scientist Philip Soole said.
Poropat explains that higher quality images of previously inaccessible rock faces means that surveyors and geotechnical engineers can provide a safer assessment of rock mass structures.
“We can actually get access to areas of the rock face that you couldn’t get to before, because either it was too dangerous to go there, or you just physically couldn’t reach it,” Poropat said.
“We can also give much better measurements on the spacing between joints and discontinuities, critical for the stability analysis.”
The scientists responsible for developing Sirovision recently won the national finals of the Enterprise Development Institute (EDI) of Australia’s Enterprise Workshop Program.
The EDI Enterprise Workshop Program assists budding entrepreneurs in developing a comprehensive business plan for their organisation.
The program played an important part in developing a successful business plan for the distribution of the technology and funding of further research. CSIRO Exploration and Mining scientist Philip Soole explains the benefits of entering the Enterprise Workshop Program.
“We really needed to get a better handle on what the business model might be, which is why we went into the enterprise workshop,” Soole said. Funds from the commercialisation of Sirovision are going towards further innovation in the existing technology.
“The development of the Sirovision technology has been part of a global boom in imaging technology,” Poropat told Australian Mining.
“There is much research going on globally into vision technique, technologies, image analysis, and how you create and use 3D data,” he said.
“There is a whole range of the top companies that use the system, it is basically being used on every continent except Antarctica,” Soole added.
As well as the safety and efficiency benefits of the new technology, mine operators are finding Sirovision cost effective.
The photogrammetry system will cost between $15,000 and $20,000 where equipment with similar capabilities, such as laser mapping systems, could cost up to $250,000.
The hardware required for open cut Sirovision software is readily available and can be found on the shelves of local camera stores, in the form of a digital SLR camera with a fixed focal length lense.
An underground rig for the Sirovision hardware has been developed due to the necessity of keeping people away from the exposed face of underground mining operations, explains Poropat.
“Following the drilling, blasting and excavation process in an underground drive, the rock is not supported in any way,” he said.
“Until the bolts and meshing is put in place they can’t allow people into that zone.
“Geologists have to get images very fast in a completely different operating manner, fast enough so it doesn’t impact on the cycle times in the mining cycle.”
Sirovision is proving cost effective as the mapping process requires less labour and is becomes increasingly automated.
“The technology allows much higher levels of automation in terms of how the images are created, thus effectively lowering the cost of the acquisition of first stage data,” Poropat said.
“This technology is not just confined to the mining industry,” Soole added.
“With sophisticated mathematical techniques and reasonably advanced computational geometry, the technology will get more and more sophisticated and the mapping and analysis process will become more powerful,” He said.
“We are currently working with the resellers Gemcom and Datamine which are a critical part of the global strategy for this technology.”
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