The Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) in the Electrical and Computer Engineering Department is in the process of adapting its weather radar networks so they can also detect small drones. In part, CASA’s new initiative is designed to address industry estimates that there could be as many as 3-million drones in skies worldwide by the end of 2017. As the UMass News Office reports, “The [CASA] system is designed to scan the airspace closest to the ground where drones and severe weather are not currently visible to existing weather radar and aircraft surveillance systems. The project is funded with an 18-month, $200,000 grant from the National Science Foundation (NSF).”
The title of CASA’s NSF Proposal is “Proof of Concept Multifunction Micro-drone and Weather Surveillance System.”
Michael Zink, associate professor of electrical and computer engineering and co-director of CASA, says that CASA researchers have already demonstrated that a dense network of short-range radars can track tornadoes down streets and anticipate areas where flash flooding might take place. “With this new grant, we want to show that we can use the same system to also monitor the airspace for low-flying drones that might breach secure facilities or threaten public safety,” says Zink.
The News Office report observes that, as the number of drones increases, so will the chances that they will pose a danger to public safety. In Massachusetts alone, at least 80 near-collisions between drones and other aircraft have been reported to date.
“There is a growing market for technologies that can detect the presence of a drone,” says Apoorva Bajaj, innovation manager at CASA. “Solutions range from using microphones and cameras, to intercepting the radio communications between the drone and the operator. We believe that a radar-based detection solution will provide the earliest warning of drone intrusions.”
As the News Office explains, National Weather Service radars scan the skies across the nation for developing weather, but, because they are located 100 miles or more apart, the curvature of the earth means they can’t measure what is happening in the first few hundred feet above the Earth. CASA has developed and deployed an array of seven short-range weather radars in the Dallas-Fort Worth area of Texas that are capable of spotting weather such as tornadoes that form close to the ground to provide public officials with timely and highly accurate storm information. The system is being used by 50 cities and counties in the region, and a mobile app developed by CASA delivers severe weather alerts based on user preferences and location.
But drones are different from weather systems. The News Office notes that, since drones can move at very high speeds compared to weather, the researchers plan to use phased-array antennas, capable of using multiple radar beams to scan the atmosphere. A second key aspect of the system is that it uses dual polarization technology that could help distinguish between hard moving targets, such as drones and birds and their flight patterns.
Bajaj says one of the goals of the project is to develop a library of information on what different objects look like. “We will collect the radar signatures from different types of drones and from other objects such as birds,” he says. These can be used to develop algorithms that will help the radar quickly and accurately identify objects moving in the air space.
Zink notes that the new system will be developed and refined using existing radars located on the UMass Amherst campus. He also says the new system will be able to help airport managers and others determine whether a drone is approaching a sensitive area, but it won’t be capable of stopping or grounding it. “We will provide actionable information, but others will have to decide how to respond,” he says.
Both Zink and Bajaj say the project could have future commercial applications for airports, urban areas, or other places where accurate weather and drone-intrusion information is part of providing for public safety. (October 2017)