To help conduct its mission of testing counter-drone solutions in different environments, the Department of Homeland Security Science and Technology (S&T) Directorate this month will conduct a week-long test of technologies to detect, track and identify small unmanned aircraft systems (UAS) in Richmond, Va., which will serve as a new testbed representing a dense urban setting.

Richmond provides the “noise level of a city” with its high radio frequency environment and the “structure of a city” with tall buildings and reflection and blockage of signals, all of which are nearly impossible to simulate for realistic testing, Shawn McDonald, a program manager in charge of S&T’s Air Domain Awareness program, said in a July 1 interview.

If a radar is set an elevated position, it will pick up fans on building tops, which have a spin such that they look like rotors on a drone, creating false alarms, McDonald said. If cranes are being used for construction projects in a city and they “move and swing and move stuff up and down,” that also adds to the noise.

“All that stuff is clutter in an urban environment,” he said.

State and Local Buy-In

The Virginia capital is also attractive because the Virginia Department of Aviation is doing work in drone traffic management, and state and city officials have been accommodating, noting that S&T’s work on counter-UAS (C-UAS) fits within the overall goal of making the airspace safe for legitimate uses of drones, McDonald told HSR.

“It only takes one or two to be out there doing bad things and then everybody wants to shut down the airspace for the legitimate use of UAS,” he said.

The upcoming testing in Richmond “is a big deal for us,” McDonald said, noting that it has involved “a lot forward leaning” by the state and city.

Another reason S&T, Virginia and Richmond want to work together is because the Biden administration has proposed expanding counter-drone authorities to state, local, tribal and territorial governments. The administration’s plan would also expand the tools and limited authorities used by the Departments of Defense, Homeland Security, Justice and State, and the CIA and NASA to detect, track, identify, and in some cases mitigate and defeat potential threats from small drones.

Small drones are popular with recreational users, whose activities at times can interfere with airport operations and commercial flights, and cause concern for owners and operators of other critical infrastructures. Small drones are also being used by bad actors for surveillance, to smuggle drugs and contraband into prisons, and in some cases to be weaponized.

“So, we believe sometime in the future that state and locals will probably have some limited ability to do detect, track, ID and possibly even mitigation,” McDonald said, later adding, “The engagement with Richmond is to also start that start that discussion with the state and locals.”

For an urban testbed, S&T did look at using Defense Department facilities that are built as “mini cities” but without any people, McDonald said. This would have required simulating the RF background and reflections but was “just too difficult,” he said.

Multimodal Sensor System

For the upcoming test, S&T will use a multimodal sensor unit installed on a tripod in a fixed-location and that will include radar, passive RF collection, electro-optic and infrared cameras, and an Automatic Dependent Surveillance-Broadcast for tracking flights, all of which will be integrated into a tactical picture, McDonald said.

Having a multimodal system reduces reliance on a single sensor, and in an urban environment if there is a lot of reflection that makes it challenging for radar, the other sensors can help with detecting and tracking a small UAS, he said.

The tripod system has been tested out in contractor and government facilities and the testing in Richmond will be in “kind of the toughest of the environments,” McDonald said. From there, operators plan to take the system wherever they want to for an operational assessment and will give S&T feedback on its performance, he said.

A second tripod-mounted sensor system is currently being integrated but is about two months behind the system that will be used this month, McDonald said.

The testing will be for research and development purposes, not to score vendors’ technologies, McDonald said, but to understand system performance. Using test drones in “some unique flight patterns” will help “characterize how this stuff works in the cities,” he said.

S&T will also be measuring any collateral effects on nearby networks and communications from the use of the C-UAS technology, McDonald said. In previous testing there haven’t been any negative collateral effects, he said.

The Air Domain Awareness program last year conducted evaluations of detect, track, and identification systems against small aircraft and UAS in a plains environment in North Dakota, mountainous terrain in Montana, and a maritime environment on the West Coast with the Coast Guard.

The land-based maritime testing hasn’t been publicized but McDonald said that in addition to detecting, tracking and identifying UAS, systems were used to mitigate drones “in a somewhat urban and coastal environment.”

McDonald described the test done in the maritime environment as challenging but “not as challenging” as in the urban setting.

McDonald also said that S&T is partnering with another agency that is bringing acoustic sensors to see how well they work in a downtown environment. The acoustic sensing will be separate from the tripod-mounted multimodal sensor, he said.

The next round of testing in Richmond hasn’t been scheduled yet.

In the plains and border environment, S&T is pursuing additional C-UAS testing. Last fall, S&T awarded a $1 million contract to the Univ. of North Dakota to evaluate capabilities to mitigate threats from small drones.

McDonald said that UND will do a C-UAS test in 2023 and another in 2024. The contract was awarded through the Federal Aviation Administration’s Alliance for System Safety of UAS through Research Excellence, he said.

S&T does its C-UAS testing to help DHS components understand the performance and capabilities of technology solutions. The Coast Guard, Customs and Border Protection and Secret Service have all used counter-drone systems for their operations. The Transportation Security Administration is evaluating the technology to help protect airports from drones operated by the careless or clueless, or by nefarious actors.


In June, S&T issued a Request for Information for support in the area of systems to detect, track, identify, report and counter small drones, and for performing RF spectral measurements of C-UAS technologies.

S&T said it is interested in learning about systems that can be deployed on manned and unmanned aircraft and tethered platforms for detecting, identifying, classifying, tracking and or mitigating small drones. It added that the system would primarily be used for manned flight safety in the border environment.

In addition to flight safety, the technologies aboard a manned aircraft could also be used for C-UAS missions, McDonald said. And whether it’s a manned, unmanned or tethered asset, having an elevated sensor system provides advantages, including less RF blockage from buildings, foliage and waterfowl, and it allows for increased range, he said.

If vendors answer with technologies that are relatively mature, then S&T will establish a demonstration program to see how well they work, McDonald said, adding that he believes there are a number of systems out there at a technology readiness level of five or higher that could be demonstrated. For less mature technologies, small business innovation research contracts are possible, he said.

Vendors that supply drone detect, track and identification capabilities as a service are also of interest to S&T, the RFI said.

Regarding support for testing RF of C-UAS technologies, S&T wants to learn about existing facilities, in particular anechoic chambers, that specialize in characterization of systems.

The RFI said that S&T also wants to learn about existing solutions for fusing disparate sensor data for the C-UAS mission and about existing solutions for command and control of disparate C-UAS assets. For sensor fusion, McDonald is interested in being able to bring sensor data together at an operations center where a lot of computer processing power can be brought to bear, he said.

There are not a lot of anechoic chambers around which means it’s difficult to get time for testing so S&T wants to survey and get an understanding of what else may be available, he said.