By Moussadak Mezouaghi
Imagine taking a quick scan of your project and, by comparing to last year's scan, detecting slight shifts in a foundation that can be repaired before they become a problem. Also imagine running alongside a 100-mile-long gas pipeline and sniffing out even the slightest of leaks, all within a single day; or peering into a tower from every angle, then repeating the examinations from precisely the same vantage points on a regular schedule – automatically detecting when a single cotter pin slips or a metal support bends out of shape.
Such thoughts represent ongoing and future applications of unmanned aerial systems (UAS) in commercial applications. The systems offer particularly bright prospects for improved speed, safety and documentation on design and construction projects, as they help streamline multiple workflows and reduce costs for mapping, monitoring, analysis and data gathering.
The Federal Aviation Administration (FAA) is working to enable growth in the use of UAS, better known as drones. In late August, the agency announced new rules regulating the commercial use of UAS weighing less than 55 pounds within U.S. airspace, addressing some of the limitations associated with existing exemptions. Working with various stakeholders, the FAA worked to make the technology accessible to the construction industry. Although the rules address basic operations of a UAS, a user can file for a certificate of waiver, if necessary, to address specific needs such as operating at night, reaching beyond the user's line of sight and operating multiple UAS.
The possibilities of using UAS are growing every day, and our research and development efforts are focused on how the use of this new technology can simplify current processes.
Generating a Positive Buzz
Before UAS came long, we relied on imagery data captured from a satellite or an airborne manned survey. Because these traditional methods carry relatively high costs, especially for work in smaller areas, UAS surveys have emerged as a particularly effective solution for collecting data during the life cycle of a construction project – and at a fraction of the cost. UAS flights provide better documentation of a project's progress throughout time, and site conditions are documented both pre- and post-construction, which can be useful for remediation work. UAS use also can uncover actual and potential safety issues, particularly after a tornado, forest fire, heavy rains or other event that might otherwise limit accessibility to the site.
Just as experience is critical for a successful construction project, the same holds true for optimizing the use of UAS on your site. Before launching such efforts, it's important to know your system's limitations and capabilities. Once data is collected, effective processing demands in-depth knowledge of photogrammetry techniques to help transform the raw imagery into useful assets: a 3-D model of your building, photo-interpretation of your Multispec/Near-infrared data, or perhaps a digital surface model that can be used for site planning and calculations for cuts and fills. The most common data sets collected from UAS – color photos and videos – are excellent for inspections of assets including transmission lines structures, telecommunication towers, wind turbines and the steel under bridges. Also, near-infrared and multispec features can be used for vegetation management and wetland delineation.
An infrared sensor can be mounted on a UAS to inspect beyond what can be detected by the naked eye. Think of a heat map for a large solar panel farm: A hot area in a sea of red could indicate a defective panel. Sensors can detect hot spots inside substations, gas leaks along pipelines or thermal loss in buildings.
The search for advancements and additional applications continues. As sensors continue to shrink in size and batteries become more efficient, expect users to continue pushing for expanded opportunities – for example, extending the use of UAS beyond visual line of sight, or for deployment lasting hours at a time. Automation looks to be particularly promising, as a user could schedule a drone to run routine checks of assets before the assets' warranties expire. A few minutes of programming, and an hour or two of visual inspections and change detection, could save thousands of dollars in otherwise lost revenues– particularly as the internet of things allows for prompt decision-making, immediate filings and rapid replacements of equipment.
In the future, look for industry leaders to expand the possibilities for using UAS across lines of business and deliver innovative solutions that will continue to change the industry.
Moussadek Mezouaghi is a senior UAS and geospatial specialist at Burns & McDonnell, where he leads research and development efforts in the firm's drones program. He has more than 13 years of experience in remote sensing and geospatial data management for projects involving electric transmission and distribution, oil and gas, flood risk assessment, and municipal land information.