Drone Detection in Restricted Airspace
I got pulled into something recently that I did not expect to be anywhere near: real-time drone detection in restricted airspace, working alongside Luke Air Force Base and Phoenix Police during Luke Air Days, March 24-26. Glendale PD came into the picture later, during an intercept, because of where the operator happened to be standing.
The Problem
Big public events bring out big crowds, and somewhere in those crowds there’s always going to be someone who decides it’s a good idea to put a drone up for a better view. Most of the time it’s not malicious, just oblivious. But when it happens in restricted airspace, or anywhere near a sensitive location, the intent doesn’t really matter. It’s still a problem, and it’s a problem that has to be dealt with in the moment.
The thing is, most teams on the ground don’t have a clean way to actually see what’s in the air, much less figure out where the operator is standing. People assume radar handles this, and in some environments it does. But standing up radar for a temporary event isn’t simple. There’s regulatory overhead, setup time, and coordination involved that doesn’t line up with how fast things move at a live event. Phoenix Police can’t exactly wheel a radar array into a downtown street closure on short notice, and Luke Air Force Base has its own constraints around what gets deployed and where.
That gap is what makes room for something different.
The Approach
What I worked on came down to passive RF sensing. Rather than putting energy out into the spectrum, the system just listens for the signals drones and their controllers are already broadcasting. It doesn’t transmit anything itself, which is a big deal in practice. No spectrum authorization, no coordination headaches, and it can go from a case to a working sensor in a short amount of time.
My part was the software that takes the data coming off the passive sensors, processes it, and pushes it into the C2 as Items of Interest so operators actually have something to look at. That’s where most of my time went. Raw RF in a public environment is a mess. There’s WiFi everywhere, Bluetooth from every phone in the crowd, video feeds, push-to-talk radios, and a hundred other things bouncing around. The software layer had to help reduce all of that into clean, prioritized items based on signal characteristics, proximity to the area we cared about, and a few AI-assisted checks on top of the sensor pipeline.
The end result, from the operator’s perspective, was a pretty straightforward picture. A map, real-time items dropping in, and enough filtering on my end that the person at the screen wasn’t buried in noise. When something showed up inside a restricted area, the team at Luke and the officers from Phoenix Police had a starting point to work from instead of trying to figure things out from scratch. When jurisdiction pushed the response outside Phoenix PD’s area, Glendale PD became part of the loop.
A Real Intercept
The clearest moment for me was the first time the whole loop actually closed in the field.
We were set up in the TAC, where the camera feeds and other monitoring views were already part of event coordination, so the drone feed fit naturally alongside the rest of the sensor picture. We were watching the C2, and one of the Items of Interest my software had pushed in lit up inside a no-fly zone. The passive sensors were picking up live position from the aircraft and, just as importantly, a location for the operator on the ground. So we weren’t just looking at a dot in the sky. We had a pretty good idea of where the person flying it was standing.
The operator turned out to be sitting outside Phoenix PD’s jurisdiction, so Phoenix coordinated with Glendale PD, who had officers in the area. From there it was a matter of relaying what we were seeing. I walked the Glendale officers in using the live lat/long off the C2, updating as the operator moved. They closed the distance, made contact, and let him know he was inside restricted airspace over an active base and needed to bring it down.
No chase, no scene, no escalation. Just a quick, quiet correction, which is exactly what you want at an event like that. It was a small example, but it was the moment the whole approach stopped being theoretical for me. Passive RF in, ground response out, and the gap in the middle filled by the software I’d written to turn raw sensor data into something an operator could actually act on.
What Surprised Me
The thing I keep coming back to is how early this whole space still is in the real world.
The need isn’t a mystery. Drones are already showing up where they shouldn’t. Everyone working these events knows it. The technology to detect them isn’t exotic, and the math behind it isn’t new. But somewhere between procurement, regulation, and the lack of any real standard tooling, there’s still a wide gap between what’s technically possible and what’s actually sitting in front of an operator on a Friday night.
Remote ID
A lot of why this works at all comes down to Remote ID.
Remote ID is the FAA’s broadcast identification standard for drones. It’s conceptually close to ADS-B for manned aircraft. Compliant drones broadcast their position, velocity, and a reference point for the operator over short-range radio. A passive sensor can pick that up without putting anything back into the air, which is exactly what makes it a workable foundation for a detection system in a public environment.
The catch is that it only covers drones playing by the rules. If someone disables Remote ID, or flies hardware that doesn’t follow the spec, you need to fall back on broader RF analysis to pick them up. That’s a harder problem, but it’s where the more interesting work lives.
Takeaway
This was a small slice of a much bigger problem space, but it made one thing clear pretty quickly. There’s a real operational gap, and you don’t need anything wildly complicated to start closing it.
Passive RF sensing with a sensible software layer on top can be deployed quickly, sidesteps most of the regulatory overhead, and gives people like the team at Luke Air Force Base and the officers at Phoenix Police and Glendale PD something concrete to act on instead of guessing.
I’m still new to this space, but it’s one I’m paying close attention to. Drones are getting cheaper, more capable, and more common, and the systems we use to manage them are going to have to catch up whether we’re ready or not.