Mobile Laser Scanning
Mobile Laser Scanning is an emerging technology that is ideal for surveying various types of infrastructure corridors including road, rail, pipelines and powerlines.
MNG was the first surveying company in Australia to fully embrace the potential of high-density, high-speed laser scanning technology. In 2010 MNG coupled high-speed 360° LiDAR scanners with high accuracy GPS and inertial technology to create a Mobile Laser Scanning operating system.
The company also developed its own in-house data capture software, suitable for field operation, and methodologies to ensure the highest data quality in the field. These include developing targeting systems that completely eliminate the need for surveyors to work on or near the road or rail line. MNG uses a combination of LiDAR processing packages and in-house programs to optimise every stage of data processing from combining and checking data sets, transforming the results to a local map reference and extracting the point and string information required by our clients. Utilising the company's own in-house developed software allows flexibility to provide clients with data that satisfies their specific needs.
MNG's commitment to Mobile Laser Scanning innovation and technological advancement has seen it recognised and rewarded within Western Australia, collecting prestigious awards for their MLS project work on various infrastructure projects.
Road Corridor Mapping
The MLS system can be deployed on any mobile platform, including road vehicles, and allows road corridors to be mapped with unprecedented accuracy and efficiency. The system's rotating laser collects hundreds of thousands of points per second, measuring everything visible to the scanner within a 30m range of the vehicle to within a few millimetres accuracy to create a survey-accurate 'Cloud of Points'. Video imagery data is simultaneously captured by a 360° camera, allowing for a comprehensive, high accuracy data set to be produced along any road corridor.
In addition to being an extremely powerful measurement tool, MNG's MLS system offers significantly increased levels of safety for operators when compared to conventional surveying techniques. This has resulted in the technology being highly regarded and accepted as a preferred tool by industry to ensure the highest levels of safety for project surveyors. MLS operators work safely inside the cab of the scanning vehicle and are not required to work outside on or near the carriageway during data collection.
Zero Traffic Impact
MNG has developed a Zero Traffic Impact survey method, which is particularly important when surveying freeways and roads with high traffic counts. This method utilises MLS and Terrestrial Laser Scanning, which is used to provide road control targeting from scans taken from bridges and overpasses. With this technique, road corridors can be surveyed with the vehicle travelling at traffic speed. Lanes do not need to be closed or traffic diverted, nor do works have to occur at night when roadways are less congested.
This methodology is only possible due to MNG's proprietary processing algorithm for mobile LiDAR survey data. This methodology sees fewer control points required to complete the survey, which makes the Zero Traffic Impact method viable.
Data can be extracted from the 'Point Cloud' for a range of applications including centreline alignment, measuring road edges and line markings, digital terrain models of road surfaces and surrounding corridors, asset identification and location and clearances to nearby structures.
Speed of Data Capture
MLS data is collected on a moving vehicle at traffic speed. There is no need to slow the vehicle while data is being captured.
Once the survey is complete, the entire corridor of survey is available in one continuous data set, which can link two or three separate regions or jurisdictions together.
Accuracy of Result
MNG has developed a set of data collection and processing methods to ensure the quality and accuracy of final deliverables. Using our processes we are regularly able to achieve road survey accuracies of ±15mm.
One of the quality assurance processes we use is the use of redundant measurements, which identifies any data outliers and increases the accuracy of our results by averaging the data from each run.
Complete Measurement of Road Corridor
'Point Clouds' provide comprehensive road corridor measurement. They allow for immediately required data to be extracted from the Cloud to meet immediate customer needs, however further information can be extracted at a later date without the need to return to the field to collect data.
Common applications for road surveys include:
- "As Built" surveys to confirm newly constructed road works meet design specifications
- Current road condition (cracks, potholes, edge of bitumen) for maintenance inspection purposes
- Confirmation sufficient road surface topology exists to ensure water run-off. Flat sections of road surface can be identified that may cause aquaplaning for cars in wet conditions
- Alignment of the existing centreline and edge of bitumen for road widening, upgrade or re-alignment
- Locating line markings for planned road mergers or establishment of passing lanes
- Establishing digital terrain models of the surrounding landform in preparation for earthwork calculations required for new roads, road widening and further construction
- Locating all hard surfaces and structures (road barriers, bridges, culverts, kerbs, gutters, road signs and power poles)
- Accurately establishing clearances under bridges
Rail Corridor Mapping
Built specifically to address client requirements for speed, accuracy and safety, the MNG MLS operating system is perfectly suited for rail infrastructure corridor surveys.
Able to be deployed on any mobile platform, including trains and HiRail vehicles, the system's rotating laser collects hundreds of thousands of points per second, measuring everything visible to the scanner within a 30m range of the vehicle to within a few millimetres accuracy to create a survey-accurate 'Cloud of Points'. Image data is simultaneously captured by a 360° camera, allowing for a comprehensive, high accuracy data set to be produced along any rail corridor.
The MLS system provides unmatched levels of accuracy by allowing the track centreline to be measured directly from the scan image. All other items can then be referenced in the scan relative to the track centreline. Any point can be assigned a chainage and horizontal and vertical offset along the track with respect to the plane passing through the two rail heads.
The measurement and assurance of clearances is a key requirement in the management of railway systems. The captured LiDAR 3D Point Cloud can be used to extract clearance information from the digitised rail corridor.
A predefined clearance gauge or profile can then be run through the Point Cloud and all incursions into this gauge can be documented and highlighted. These incursions can then be displayed in profile (see Figures 2 and 3) and annotated with the distances to the rail centreline.
The clearance profiles can be static to define the widest possible area of the train profile or, alternatively, can be kinematic and adjusted during the gauging process. This allows for the dynamics of the rolling stock with regard to the radius and cant of the track.
This technique is particularly useful for platform and bridge clearances where very accurate offsets can be given relative to the track centreline.
Rail Geometry Comparison
The effectiveness of the MLS system means track rails can be captured with a high degree of accuracy. Consequently, rail geometry items such as curve radius and cant can be computed at all points along the line. The geometry measurements can then be compared to the original design and a report generated to highlight any areas of significant deviation from the intended design.
Geometry can be analysed and vertically and horizontally derived from the 3D Point Cloud measurements - showcasing the extremely powerful and accurate measurement abilities of the MLS system.
Ballast Profile Determination
The state of rail corridor track ballast is easily determined and evaluated by MLS systems through inspecting ballast cross section profiles at intervals along the rail profile. An automatic routine can then trawl through the Point Cloud and highlight areas where the existing ballast does not meet a predefined ballast template.
Under normal conditions, the 3D Mobile Laser Scanner can identify, locate and map features such as signs, lights and gantries up to 30m from the track centre to a very high level of accuracy. From the LiDAR survey a full map of the rail corridor can be produced.
Terrestrial Laser Scanning
Providing a safer, more precise alternative to traditional survey and dimensional control methods, MNG's Terrestrial Laser Scanning services are able to capture, visualise and model complex structures, sites and features.
Conducting laser scanning operations from a distance of 100m with 6mm accuracy, MNG is able to acquire precise data in potentially unsafe working environments in both day and night conditions.
Acquired data can be modelled and rendered for easy integration into CAD and various modelling software such as PDMS, AutoPlant and Navisworks.
- Dimensional Control Surveys
- Structural Tie-Points
- Fabrication & Construction Quality Assurance
- As-built Surveys of Plants and Facilities
- Conceptual Designs for Clash Detection
- Public Infrastructure Modelling
- Stress Analysis
- Architectural Facades
- Historical and Heritage