Surveying the Broadband Superhighway at Road Speeds, Vehicle Mounted LIDAR Surveys for the NBN
The Taylors NBN journey started back in July 2010. The NBN project was in its infancy. A trial rollout had begun in Tasmania and the project was gaining some media coverage, however the coverage was largely political and few in the mainstream business community had started to turn their heads in the NBN direction. In fact, in the wake of the GFC many businesses were still picking themselves up and dusting themselves off, particularly businesses heavily exposed to the development industry, which of course includes most surveying firms. Though inexperienced in the space, strategically we were well positioned given that two years earlier we had established an infrastructure team to target projects such as this.
When we began our investigations in to the NBN we knew we had a long road ahead of us. The majority of our previous work had been in the property industry and as such we had very little experience in the surveying of electrical infrastructure. So in order to learn more, we immersed ourselves in the space. We attended every NBN seminar and information session we could find, we spoke to businesses and people in the telecommunications industry and we read every publication we could get our hands on. Pretty soon, two things became clear. Firstly, that the NBN was an immense undertaking and that the size, scale and speed in which it would be built meant this would be a once in a generation project, the likes of which we had never seen. Secondly, that the current survey practices and resources in the electrical infrastructure construction industry would not be sufficient to deliver this project.
We turned our investigations to finding a suitable survey methodology that would be fit for purpose to the NBN project. The greatest challenge to overcome was NBN Co’s ambitious rollout program, with NBN Co planning to rollout to 3.5 million premises by 2015 and full completion by 2020. We knew that traditional methods would not keep up and that the existing resources in the electrical infrastructure surveying industry would not meet the demand. We considered a number of existing technologies and ruled out the approaches that would not meet the requirement. Traditional total station work would be appropriate for small sections of cabling but too slow for the mass survey of entire suburbs. Measuring wheels and extendable poles would be too inaccurate to produce the reliable results required for major project design works. Fixed wing Aerial LIDAR was a great tool for collecting masses of data quickly and indeed it was commonly used for the larger electrical transmission lines, but it was considered too inaccurate for the smaller electricity distribution networks that run through suburban streets. Our research soon led us to a relatively new technology called vehicle mounted LIDAR or mobile mapping.
LIDAR uses ultraviolet, visible, or near infrared light to image objects and can be used with a wide range of targets. Accurate vehicle positions are obtained using three redundant technologies: a dual frequency GNSS receiver establishes a geospatial position; an Inertial Measurement Unit (IMU) tracks vehicle position; and connection to the vehicle CAN bus or external wheel encoders obtains odometry information. These three technologies work together to sustain a highly accurate 3D position for the vehicle even in locations where satellite signals can be blocked by obstructions such as buildings, bridges, or tree lines. Vehicle LIDAR can provide extremely fast survey results for large-scale projects. A further important component of the system is its capture of high resolution 360 degree imagery. The system logs imagery at user nominated intervals to create georeferenced images or video logs. This element further enhances the design engineer’s ability to review field conditions and clarify issues from their desk top without attending the physical site. The vehicle is able to travel at speeds of up to 80km per hour and as such masses of data can be collected in a short amount of time. Further, the proximity of the vehicle to the power lines as it drives along the road mean that accuracies of +/- 50mm can be achieved. We were confident that a vehicle mounted LIDAR solution was a good fit for purpose solution for the project.
With a field survey solution in place we began to map out the office tasks. One challenge unique to vehicle mounted LIDAR that we would need to overcome was the large volume of data that would need to be managed. As well as storing, transporting and housing that data, we would also need the software, computing power and expertise to work with the data. So we invested in point cloud data software. Over a 12 month period we utilised vehicle mounted LIDAR to deliver surveys for a sizeable sewerage scheme in south eastern Victoria, a pipeline in Warrnambool and a recycled water project in Coburg. The site would be surveyed using mobile mapping and the data sent back to our head office, where our surveyors would extract the required survey data and produce the final survey model.
Soon after, we delivered our first batch of NBN data. It was both the end of a long journey to secure work on Australia’s biggest infrastructure project in more than 80 years, and the start of a long journey as we continue look to build our capability throughout the NBN project life cycle, which is expected to take over 10 years to build. During that time we have upgraded our business systems, trained and developed our people to work in a new surveying frontier, improved our survey methodology and quality assurance procedures and developed a reputation for both ourselves and our client as a premium provider of NBN spatial data.
Taylors are very proud and excited to advise that our NBN Solution won the SIBA 2013 Victorian Spatial Excellence Award for Innovation and Commercialisation.