Electrical contracting companies involved in the installation of underground power or communications cable must know the locations of existing buried utilities before beginning excavation or directional drilling.

A lot of infrastructure is buried close to the ground’s surface. According to March 2015 utility damage-prevention statistics, the United States is host to 20 million miles of underground pipe and cable, and more is added every day.


The nation’s One-Call system is the backbone for initiating utility locates, and most of that work continues to be done using handheld electromagnetic tools and by marking the paths of cable or pipe with color-coded flags or paint. However, these instruments require the buried utility to transmit an electric signal to make locates—absent on many steel and plastic pipes and conduits. Other locating options are available but have limitations. In addition, sanitary sewers and pipes open to the atmosphere, such as storm sewers, are often not located through One-Call. 


Despite continuing improvements in One-Call procedures and the adoption of new technologies into the process, many utility hits result because locates were made improperly, One-Call was never contacted, requested locates were not made or were completed late, or markings were inaccurate.


Now, picture this: a construction project in a well-developed part of a city where a directional drilling crew is preparing to install a section of gas pipe in an easement already containing multiple utilities. The foreman looks at a tablet screen that displays a real-time view of the work site (streets, sidewalks, trees, buildings, etc.) as seen by the device’s built-in camera.


Look closer. Not only does the image on the screen show the live scene, it clearly depicts what is beneath the ground with images of color-coded pipes and cables, ducts and manholes—showing their precise locations in relation to the real-time picture of the surface.


This is happening today, but on a limited scale. The technology has the potential to drastically change the way buried utility locations are mapped, said Mark Wallbom, chief financial officer and executive director of Hydromax USA, an independent professional services firm specializing in data collection in support of locating and assessing the condition of the country’s aging underground utility infrastructure. 


“Superman could see through buildings and under the ground with X-ray vision,” Wallbom said. “While impossible, the concept is not foreign to us. With a little help from technology, we can, in fact, see underground. We call it ‘augmented reality’ because two or more technologies are combined in an interoperable fashion that allows the viewer to see things that are visible in real-time, along with other elements that are contextually added to the view, thereby creating an immersive experience that enhances reality in ways that make it more meaningful to the viewer.”


Using a service provider with a database that contains the digital subsurface dataset of the work site that was previously mapped using various geophysical tools and survey grade positioning instruments, the returned 3-D images are incorporated into the smart device, and the images are combined and displayed on its screen.


The technology isn’t new. Its origins date back to the late 20th century.


“Flash back to Sunday, Sept. 27, 1998, and a memorable night in television history,” Wallbom said. “ESPN’s broadcast of the Baltimore Ravens-Cincinnati Bengals game introduced the now-ubiquitous ‘magic’ yellow first-down marker. In order to make the experience one that added value to the viewer, this augmented line had to appear as if it were painted on the field while remaining in perspective as the action—being shot from multiple cameras with different focal lengths—continued to swirl around it. This magic line had to appear as though it was under the players’ feet and not on top of their jerseys. While this concept was first patented 20 years before, the vision existed, but the technological ability to bring the vision into reality had not yet been developed. This fact did not impede ongoing development of the concept, and, of course, today we expect to see these visual aids that significantly enhance the viewing experience.”


Augmented reality can be applied to underground facility mapping. 


“By adding georeferenced subsurface elements, such as electrical cables and conduits, to the view seen through the lens of a handheld device such as an iPad, the viewer is able to recognize the location of these features, in real-time, and in full context of the environment being observed,” Wallbom said. “While looking through the lens of the camera on a viewing device that employs enhanced locating capabilities such as GPS, the user can add interoperable elements from the cloud or an onboard storage cache, so that, at any angle, the view seen on the screen is in correct perspective and orientation. Through the use of a geographic information system [GIS], attributes that were previously appended to these observable features (such as a fire hydrant or communication pedestal) or subsurface features (such as valves, pipe type and size, service and manufacturing records) can be embedded, which greatly enhances the value of the information.”


To relate to the real-time view from the camera, the underground map must be in a digital format with survey-grade control points imbedded into the database.


“Within the boundary of the survey, [it] is possible to point the device at, for example, a fire hydrant, and see an augmented representation of the underground pipe that serves the hydrant,” Wallbom said. “As the person holding the device moves around the site, so does the image of the subsurface. In addition to the hydrant’s pipe, the image also would show other pipes, cables and anything else that was captured in the 3-D subsurface survey, providing an enhanced view of reality.” 


Being able to see the relationships between above-ground structures and below-ground infrastructure offers multiple advantages to engineers, planners, contractors, property owners and emergency personnel. One benefit of contextually being able to see the above- and below-ground physical plant when each are georeferenced could be a “decision-tree” that would encompass relevant information that has never been previously available, on demand, in one place, at the same time. Such a decision tree may provide any number of details important to utility crews responding to an accident where there is a downed power line.


Other uses might be to alert first responders of risks or required steps to take when approaching locations, such as a transformer yard or pump station. The same possibilities exist within a desktop environment. If the above-ground view is in a digital format—or can be easily digitized—so that the location and orientation of the images can be registered and datasets of previously stored and georeferenced files are combined by exact colocation, then a whole new world of possibilities is created in the office or in the field.


“Service providers who do subsurface locating and mapping work for the utility companies, and/or underground infrastructure contractors who use trenchless methods, need to complete their work using the most up-to-date locating devices that provide for near survey-grade location of those utilities,” Wallbom said. “This level of accuracy—together with having a visual record of each pipe mapped that is digitally captured and available on demand—provides the utility company with the confidence that there are no conflicts associated with their underground plant.”


The future value of subsurface mapping to this detail is significant because it can become part of a GIS layer, which in turn becomes the dataset used to populate the underground visualization of utilities in context with above-ground features that—when geo and spatially combined—makes for the fulfillment of augmented reality. Because the datasets used to create augmented reality are independent and located in an ordered fashion, such as State Plane Coordinate System (SPCS) or other georeferenced system, the information that can be extracted is up to the viewer’s desire, be it a One-Call center, utility owner, pipeline or cable company, electrical contractor or law enforcement. It can also be used for permitting, auditing of appurtenances (such as manholes and transformers), or determining the size and flow direction of all previously captured pipe or cable.


If the collection of the above-ground data can be done antecedently, or is incidental to other work being done in the area and can be completed at a nominal cost, the added value to the viewer would be much like the electronic first-down line. If the subsurface data that is collected by a service provider, such as Hydromax USA, are to levels that are near survey-grade and digitally warehoused, then, at any future date, the datasets could be combined to enhance the value of the 3-D data deliverable to the client.


“In the end, it is the data that, when properly captured, processed and subjected to a rigorous quality control/quality assurance program and is made part of a GIS database, the real return on investment is obvious and turns data into powerful information that can be used across a broad group of users,” Wallbom said. “The possibilities are endless when good data and good practices coalesce.


“Sooner rather than later, the idea of being able to see above- and below-ground assets in context with each other will be as commonplace as the hot dog. Field technicians and office personnel will be able to collaborate and share timely information and make decisions in ways that are only now being considered. Think big because we are on the verge of a major paradigm shift in the way 3-D data will be collected and used,” he said.