A revolution is happening in how we map new underground infrastructure. Instead of the paper as-builts submitted after the completion of construction for a new pipeline or other infrastructure, network owners may now request a LiDAR scan of the newly installed equipment before the trench is filled. There are several reasons for this. First and foremost is that LIDAR scanning has become so easy and fast that it is literally accessible to everyone. Secondly, a LIDAR scan not only captures the survey-grade location in 3D of new infrastructure, but a lot more information besides. Thirdly, LIDAR scanning has become so inexpensive that it does not really add to construction costs. With the democratization of modern reality capture technology the availability of comprehensive, high accuracy 3D location data about underground pipelines, utilities and other infrastructure is growing.
When Leica Geosystems released the BLK360 laser scanner, this was revolutionary for several reasons; it was small, it only had one button, its price was unheard of in the world of professional laser scanners, and the result of a scan could be seen a few minutes later on an iPAD. This device was all about democratizing reality capture. The BLK360 was Leica's play to make professional-quality reality capture available to anyone who wants it.
Utilities have used LiDAR and photogrammetry for a number of applications involving above ground infrastructure, for example, for vegetation management and to reduce safety issues and costs when conducting a high accuracy inventory of above ground infrastructure. But this changed in 2018 when Lux Modus entered the pipeline mapping market with the objective to change field mapping fundamentally by making the capture of high accuracy maps of underground infrastructure accessible to anyone and at a low cost. Consisting of high-density digital LiDAR, three 13 megapixel cameras, with GNSS with base station correction the Lux Modus device only requires one touch to initiate scanning which frees the user from having to manage the system while driving around the collection area.The device can be mounted on a rig on a pickup truck and by simply driving the truck along the line prior to filling the trench captures survey-grade location information and a lot more information such as depth of cover, location of weld points, and nearby utilities. The point cloud and images are uploaded for cloud processing and within a few minutes a 3D image of the new section of pipeline can be viewed by anyone with a browser that supports HTML5 including mobile devices.
There are two use cases where LiDAR scanning can be applied two underground infrastructure. The first is when new utility infrastructure is installed and before the trench is covered. Some jurisdictions are already mandating survey-grade accurate as-builts for new installations. The second case is when existing infrastructure is exposed for repair or relocation.
The underground mapping industry has been facing two historical challenges. The first is that when new network infrastructure is installed by a contractor, the so-called as-builts that are submitted to the utility after completion of construction rarely reflect the actual location of what went in the ground. The problem is that calling a survey crew and then redlining the original design to indicate where equipment was actually installed is expensive in time and cost. Furthermore, contractors are remunerated based on how rapidly they can get new equipment in the ground, not on the accuracy of the as-builts they submit.
The second problem is the result of the first. Most of the existing location data for underground utilities contained in utility and telecom network records is inaccurate, out of date or just missing. In responding to one call locate requests, utility locators have to rely on these same utility records augmented with remote detection techniques to try to detect and identify their network equipment. Contractor often have to conduct daylighting operations using vacuum or hydraulic excavation equipment to verify what utility locators believe they have have identified and painted on the ground. Line locating and daylighting requires special equipment, software and training to do things efficiently. But even with experience detecting and identifying underground network facilities remains a slow, error prone process that can expose workers to the hazards of traffic and other safety risks and can play havoc with construction schedules.
A number of jurisdictions, realizing that the capture of point clouds is accessible and low cost, are dispensing with traditional paper as-builts and requesting LiDAR scans instead. As a result of Lux Modus this is happening in the pipeline industry in Western Canada. Lux Modus started mapping pipelines because that was the hardest use case they could find. Now Lux Modus is expanding into other sectors such as rail, power transmission, and urban mapping first in Canada and the United States and soon in Europe. Recently in Denmark two water utilities in the Greater Copenhagen and Aarhus areas are efficiently generating point clouds of underground utility infrastructure using a handheld phone and accurately surveyed control points. These point clouds are captured for both newly installed infrastructure and for infrastructure exposed during repairs of existing infrastructure. Novafos, a water company in the Greater Copenhagen area, already has thousands of these point clouds which capture not only high accuracy location of the water utility's underground infrastructure, but a lot more information including the location of nearby utilities which would be a concern for any excavation involving the water lines.
This post is based on Joseph Hlady's keynote at the Canadian Underground Forum (CUF). You can listen to all the talks at CUF on the GeoIgnite CUF Youtube channel.
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