More Airports Test RF as Counter Measure for UAS in Restricted Airspace

October 1, 2023

More airports are starting to adopt and test the use of radio frequency (RF) mitigation techniques to counter the operation of unmanned aircraft systems (UAS) in violation of civilian airspace rules. While civilian aviation regulatory agencies are welcoming the integration of more commercially operated UAS into civilian airspace, airports are responding to the growing number of incidents in recent years with counter measures to ensure drones do not interfere with regular operations.

In the U.S., the Federal Aviation Authority (FAA) now receives more than 100 reports per month from pilots that have observed UAS operating near airports or within a restricted area of civilian airspace. The problem is a unique one for the FAA and other civilian aviation regulatory agencies who want to unleash as much commercial UAS innovation as possible within civilian airspace, but simultaneously recognize rogue operators are a problem. The FAA’s method for addressing the operation of drones near airports or in violation of civilian airspace rules is currently a loose collection of reactionary penalties or fines based on what occurred. But that is starting to change, and RF is one of several counter measures under evaluation at U.S. airports.

FAA leadership established the UAS Detection and Mitigation Systems Aviation Rulemaking Committee in May “to ensure that new technologies designed to detect and mitigate risks from errant or hostile UAS do not adversely impact the safe and efficient operation of the nation’s airspace,” according to an FAA announcement about the new committee. The committee is tasked with submitting a final report to the FAA in early 2024 that will provide recommendations on how airports and other organizations that own or operate critical infrastructure or assets can detect and mitigate rogue UAS operators without limiting the operations of those who follow the rules.

But while the committee works on its recommendations, rogue UAS sightings continue, and several airports are using or evaluating the use of RF as one of several detection and mitigation methods. The agency’s Airport UAS Detection and Mitigation Research Program is actively evaluating and testing technologies that give airports the counter unwelcome UAS operating nearby, including the use of RF for detection, identification and mitigation. The program has been focusing on testing and evaluating UAS detection and mitigation systems at five U.S. airports, including Atlantic City International (ACY), Syracuse Hancock International (SYR), Rickenbacker International (LCK), Huntsville International (HSV), and Seattle-Tacoma International (SEA). The FAA plans on using baseline performance data collected at ACY to determine how airport environment variables such as geography, noise, interference and proximity to metropolitan areas impact the performance of each of the mitigation and detection systems it is evaluating.

In August, the UAS Detection and Mitigation Research Program selected an RF and cyber based UAS detection system to undergo initial testing at ACY. The system, D-FEND’s EnforceAir, comes in six different deployment configurations, including military, vehicle-mounted, and ground-level tactical versions among others. Each configuration features multidirectional antennas attached to a small central computing platform with a software defined radio and other accessories. D-FEND Solutions’ description of EnforceAir emphasizes that the EnforceAir system is not an RF jammer, but instead combines RF with cyber detection to determine the real time location of unauthorized drones for a specific swath of airspace, such as that surrounding an airport. In addition to tracking the drone, EnforceAir also determines the pilot, remote controller and takeoff position of the unauthorized unmanned aircraft. Once the system has identified a rogue drone, it uses Active RF to briefly disconnect the drone signal from its pilot’s control and force it to fly back to its takeoff location or to land in a safe location.

The entry of the EnforceAir platform into the FAA’s airport UAS detection and mitigation research program is not the program’s first use or evaluation of an RF-based technology. In May, airspace security provider Dedrone announced its own counter UAS detection technology would be expanding from initial testing at ACY to a second airport in the program. Dedrone is providing several technologies for the FAA program including DedroneTracker, an integrated “CsUAS C2” platform that takes inputs from multiple sensors including RF, radar, camera and acoustics to determine the exact location of a rogue UAS. The FAA is also evaluating another technology from Dedrone, the cloud-enabled DedroneDefender narrowband disruption device. The seven-pound device looks like a small radar gun, and provides targeted RF jamming within a 30-degree effective cone angle that extends out in front of the area that the device is being aimed at. Outside of the airport detection and mitigation evaluations it is undergoing in the U.S., Dedrone claims its counter UAS technology is already in use at “more than 100 critical infrastructure sites; 30+ airports; 50+ stadiums and 20+ non-US governments,” according to its website. The FAA’s timeline for the airport drone detection and mitigation program was scheduled to end September 30, and which technologies will be deployed at what specific airports still has not been confirmed yet.

The Transportation Security Administration (TSA) has also been using RF in its testing of what the agency calls detect, track and identify (DTI) technology for drones entering restricted airspace of Los Angeles International (LAX) and Miami International (MIA) Airports. In their August 2022 update their testing program, TSA did not name the specific technology or company providing DTI for testing at LAX or MIA. However, the announcement notes that the technology they’re testing “operates 24 hours a day, is capable of using radio frequency waves, electro-optical, radar, acoustic, and thermal imaging to identify the precise location of a UAS.”

LAX was selected as one of two TSA drone DTI technology testbeds due to the growing number of drone sightings reported by pilots landing there and detections of drones in LAX airspace by existing surveillance equipment. “Since 2021, there have been approximately 90 visual sightings and 5,200 technical detections within three miles of the LAX perimeter. So far this year, approximately 38 drones have been visually detected at LAX including a drone that was reported within 700 feet of an aircraft several days before Super Bowl LVI when SoFi Stadium and LAX were designated as no drone zones,” the FAA writes in the release, describing drone activity at LAX in 2022. The release notes that since testing began at MIA in the summer of 2021, “systems under assessment have shown minimal downtime and detected thousands of UAS flights in the vicinity of the airport.”

Drones operating in restricted airspace near Dublin International Airport earlier this year caused Ireland’s largest airport to start using RF within the new counter UAS technology it started operating in September. On three separate occasions between late January and February 2023, operations at Dublin had to be briefly suspended due to drones operating in restricted airspace. “Due to illegal drone activity in the vicinity of Dublin Airport, all flight operations are currently suspended. Further updates will follow...,” the airport wrote in an update posted to its X account on February 21, 2023. Those disruptions, among others that have occurred at Dublin in recent years, quickly lead to the airport’s evaluation and operational use of new counter UAS technology. According to a September 7, 2023, article published by The Irish Times, Dublin Airport Authority (DAA) has been authorized by Ireland’s communications regulator ComReg to jam radio frequencies or take down drones operating in restricted airspace near the airport. Ireland’s Minister of Communications specifically authorized DAA to “work or use a radio frequency jammer at Dublin Airport to interfere with the working of, or otherwise injuriously affect, any UAS [unmanned aircraft system]” deemed to be operating illegally.

On September 16, the FAA began requiring all registered drone pilots to begin operating in accordance with the rules of its Remote ID law. The Remote ID mandate requires registered UAS operators to feature a method of broadcasting the identification and location of their UAS in real-time. The agency also concluded its testing of counter UAS equipment at its five evaluation airports on September 30. While no standard counter UAS measures have been outlined for airports by the agency, it remains clear that the use of RF to detect and mitigate the operation of drones in restricted airspace will be a key aspect of the counter measures that they adopt in the future.

This article was written by Woodrow Bellamy III, Senior Editor for Aerospace & Defense Technology.

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