(This article was originally prepared as part of Radio World’s preview of the NAB Show, so it only cites sources who planned to show up at this convention. The NAB Show was later canceled. – Ed .)
Unmanned Aircraft Systems (UAS) are quickly becoming an important part of the toolbox broadcasters are using to manage tower sites more efficiently.
Drone-based tower structure studies are now widely used to diagnose the health of RF systems and broadcast structures. Additionally, technical departments use drones to take high RF measurements to analyze signal coverage and validate antenna radiation patterns.
The Federal Aviation Administration approved the commercial use of drones in August 2016. Industry experts say this has sparked an industry laden with potential applications for broadcasters, including the use of video and photos from broadcast aerials. and their structural components for preventive maintenance measures.
“It’s still a relatively new industry, where there is so much creativity and potential. The integration of technology has had a huge impact on broadcast operations, ”an executive-level engineer told Radio World.
The FAA Small Unmanned Aircraft Rules (Part 107) allow a range of businesses, such as broadcasters, to operate unmanned aircraft weighing up to 55 pounds, including their on-board systems. Drones must remain in the remote pilot’s field of view and be used during the day.
The maximum altitude is 400 feet, although an exception allows more height when operating within 400 feet of a tall structure such as a broadcast tower.
“When surveying a tower, a drone is usually allowed to fly an additional 400 feet above the top of the tower, if the aircraft stays within 400 feet of the tower laterally,” says an expert .
Advocates say drones can more easily determine the integrity of transmission lines via infrared camera inspections and more safely and accurately assess antenna performance by limiting the number of turns and analysis of in-car coverage. . While nothing can replace an actual physical inspection, they say a drone can help reduce the number of climbs, verify locations and heights of assets on a structure, and increase safety.
A number of broadcast technology companies have expanded into unmanned aircraft services since 2016 as UASs have grown in popularity.
Paul Shulins, president of Shulins Solutions, said drones, used effectively, can help reduce costs and increase margins of safety for humans and broadcast systems.
“The main operations broadcast engineers use drones for are visual tower inspections, thermal tower inspections, and antenna pattern verification measurements. He said broadcasters are quickly seeing the benefits.
“Tour crew costs vary wildly across the country, but in general it’s fair to say that drones are cheaper to operate than hiring a tour crew. They can also be deployed with very little notice, operate in a wider range of weather conditions, and provide perspectives not possible with a tower crew, ”said Shulins.
Unmanned systems are becoming a preferred method for RF model verifications, he said, for both cost and safety reasons.
“Drones have a clear advantage because generally these measurements can be taken in a single day, while measurements on the ground can take several days or even weeks. Helicopters are also commonly used for pattern measurements, but their operation is much more expensive and their flight capability is limited. “
Recently, affordable, gyroscope-controlled infrared cameras have hit the market at a reasonable cost, Shulins said, while adding that drones will never replace human tower climbers for some operations.
“What (drones) can do is help the tower crews by indicating in advance the areas where the problem exists using photos, which saves time and labor. -work. “
Jason Schreiber is Managing Director of RF measurement and consulting firm Sixarms, which has developed specialized RF measurement payloads to attach to drones. He says the new RF measurement instrumentation can be adapted and installed on a drone and enable automation and reliable data capture. Additionally, the data can be used to optimize antenna patterns and verify radiated power.
“Automation, precision in signal capture, ease of flight, large altitude range, and easy deployment make drone RF measurements a more attractive setup than the traditional pickup truck with a 30 foot pump mast.” . All broadcast standards can be measured including AM radio, DRM, FM and HD Radio, VHF and UHF ATSC and DVBT as well as DAB, ”he said.
Sixarms uses its ready-to-use Airborne Radio Measuring Systems (ARMS) software and hardware to measure and characterize broadcast antenna patterns to help identify any installation and manufacturing defects.
He said the use of machine learning and AI to capture critical RF information will continue to grow and further expand the applications of drones for RF measurement.
The drones are used not only to perform a visual inspection of the tower, but also to identify damage and structural faults, Schreiber said, using thermal imaging for hot spot analysis and being equipped with LIDAR ( light detection and telemetry) to aid in automated structure analysis.
“Sophisticated capture algorithms interwoven with drone-based position data enable unprecedented accuracy and reporting functionality. “
The explosion of drone activity in broadcasting in the United States is leading to more innovative tools and ways to use data, said Phil Larsen, vice president of airborne operations for QForce, part of QCommunications.
“The RF outline is no longer just a report to be classified. It is now a tool intended to assist broadcast engineers and help the listener receive a better signal. The drone allows engineers to examine the data immediately after the aircraft lands, ”he said.
Larsen hopes to see the broadcasting industry reach the point where a fixed drone is stationed at all tower locations that can be remotely controlled or programmed to fly on a routine basis or when needed.
“Drones and sensor capabilities are developing rapidly, so the use case will increase.” He said QForce offers a way to install a drone at each location and the ability to fly inspection operations anytime of the day all year round without the need for a pilot, on a stand-alone basis. “This is particularly useful for hard-to-reach places. “
There are some limitations to the use of drones near broadcast towers. The FAA has specific rules regarding the inspection of broadcast towers. Operators should be familiar with FAA Part 107.65 rules, experts say.
Additionally, Larsen said some broadcast tower applications require special exemptions or permissions from the FAA.
Keith Pelletier, vice president of antenna manufacturer Dielectric, said drones are a much more economical way to collect data than traditional field measurements and equipment.
“Dielectric has developed a way to characterize the antenna azimuth and elevation diagrams with the data collected by the drone. In general, this was done with a van with a large mast, which included several sets of data and thousands of collection points to analyze to determine if the antenna was performing according to the specifications of the antenna manufacturer ”, a- he declared.
The company’s involvement began when drone measurement companies began to struggle with required waivers and the time spent waiting for approvals. Dielectric proposed a method of collecting all the required data at the 400-foot level, so that no waivers were required.
The dielectric is able to assess whether the electrical characteristics of the antenna are correct when measured only in the near field. “The dielectric solution consists of drawing the entire network to analyze the near-field elevation model and compare this data to the near-field elevation model measured by the drone. 3D rendering and analysis is done using high frequency simulation software or HFSS ”, Keith Pelletier.
Essentially, the far-field elevation pattern of the antenna as simulated in HFSS is compared to what the dielectric measured at the factory to validate if its modeling is correct, Pelletier said.
“We then take the near-field elevation data collected by the drone to see if it matches the same cut in HFSS; and if so, we know the far-field elevation model when trained is correct.
There are several training programs available to obtain an FAA Part 107 license, which is required for any type of commercial job. The exam requires a candidate to become familiar with FAA airspace regulations and a variety of other rules.
“It is important to keep the airspace safe. Hobby-type drones are fun but not necessarily safe around towers, guy wires and high frequency environments, ”Shulins told Radio World.
“Either train yourself and allow yourself to operate a drone, or hire a qualified pilot with the right equipment and skills to fly your tour safely and accurately interpret the results, is the smart thing to do. “