 In the future, soldiers and autonomous vehicles will use tricorder-like sensors to measure electromagnetic fields. That might be valuable information for navigation in a GPS-denied environment. That's the kind of capability we're interested in pursuing at the Army Research Laboratory. Hi, I'm Dr. Phil Percanti, the Director of the U.S. Army Combat Capabilities Development Commands, Army Research Laboratory. Welcome to ARL What We Learned Today, a podcast where we talk with Army scientists and engineers about the science and technology that will modernize the United States Army and make our soldiers stronger and safer. Today we're going to talk with Dr. Kevin Klater, a research physicist in a lab sensors and electron devices directorate at a Delphi Laboratory Center in Maryland. Kevin, welcome to the podcast. Thanks for having me, Dr. Percanti. So Kevin, how long have you been at the Army Research Lab? I've been here for four years now. Fresh out from my PhD. Fresh out from your PhDs? So what does that mean exactly? So it means that I did my PhD in electromagnetic resonance and now I'm working in electric and magnetic field sensing. So it's kind of a shift for me, but it's really exciting. And it's also interesting to be able to see my work being applied to the soldier in a more immediate sense than it was in academia. Where'd you go to school? So I did my undergraduate at Rice University and my graduate at Duke University. What did you study at Duke? Physics and there I was actually doing magnetic resonance imaging. Oh, talk a little bit about that. What does that mean? Sure. So in traditional magnetic resonance imaging, you're basically looking at the water in the body and it gives you a nice image of the person inside, but you can't actually pick up chemical contrast. So recently there have been improvements to imaging like chemicals like carbon. So now you can actually target cancer cells, but you can only look at it for about a minute. So my work was actually being able to look at chemical contrast for much longer, like 10 minutes. That's a big leap to go from looking at chemical contrast in magnetic resonance imaging to working for the United States Army. So how'd you go from MRI physics to physics that U.S. soldiers might care about? So one of the reasons that I like applied physics is that I can actually see where my work's going. One of the things that I really liked when I came to ARL was I was actually able to see how the physics that you're doing here is being transitioned into a product for your customer, the warfighter, and how they can use that to make their lives better or safer. So what are you working on here at ARL? So I'm working on a few different projects. One of the projects that I've been working on that we've been transitioning is called mobile power meter. It's a way of measuring power without having to actually expose yourself to the harm of high voltages. So this is kind of like a remote power meter. So we've seen power companies today driving down the street and they're measuring power as they drive down the street now. Do they have this technology already? So when they're doing the power down the street, they're usually just doing the magnetic fields and not the electric fields. They're not actually measuring the voltages. They're just measuring the currents. And they do have some technology, but it's invasive. So they have to have a trained electrician to shut off power safely and then install a device in order to actually measure power. So this really allows any soldier, they don't have to be trained to measure power and become as smart as a utility. So why is it important to measure electric fields? So the electric fields are actually what's governed in the power system, right? So you have generators which generate your voltages and those voltages generate the electric fields. So when you have a power outage, it's not the fact that you turned off your computer. It's because the voltage has dropped. So by measuring that voltage, we can kind of help determine things like the stability of the grid, whether you need to kick in additional battery backup power or things like that. I see. Do you think there are other areas, other opportunities where you might be able to take advantage of measuring electric fields? Oh, absolutely. So the power grid is basically bathing us all in this electromagnetic low frequency radiation. So if you think about it, we're kind of swimming through 60 hertz fields and we can use those for other applications. So while we were out and moving around taking some experiments at field sites, we're like, hey, you know, we're getting obviously stronger signals closer to the power lines. Maybe we could use this for moving around the power lines or for avoiding power lines. So actually before I started, we had a patent for avoiding power lines. And then when I started, one of the cool experiments that we did was we strapped a sensor to the top of the car and we drove it around town and we're looking at using that now for navigation. Oh, that's kind of cool. So you think you can use it for navigation? What's the difference between using electric fields for navigation and say using the GPS, the global positioning system that we're all familiar with today? Right. That's a great question. So the global positioning system works by having a bunch of satellites in orbit and they broadcast signals down to receivers on the ground. Those signals are very weak and they can be jammed. Now the power system basically is a ground based system that's generating a lot of 60 hertz and it's very difficult to avoid that 50 60 hertz signal. We've even actually seen it by satellites in space. So like I said, we're really wherever you are on earth, you're bathed by the signal. So by locking onto that signal instead, we think we have a good option for a denial resistant method of finding navigation. Yeah, so this could become really, really important for the Army in the future and for society in general if someone were to take down the GPS system or the GPS signal we're denied and people are trying to navigate. The fact of the matter is many of us, particularly the younger people, not me because I've been a scout master for many years. I still know how to use a map and compass. However, many people don't because we rely so much on our phones. So being in a GPS denied environment can be somewhat problematic and can be particularly problematic for the Army when you need to have a short position navigation and timing. So this is a way perhaps to use electric fields to do positioning without having to rely on a global positioning system. So where are you in this research? So like I said, exactly the idea is that you can use this for measuring where you are even in the absence of GPS signals. But there's still some outstanding problems with that, right? One of the things is that it needs good knowledge of where your source signals are. Similar to GPS, you need to know where the satellites are. Here and now you need to know where the power infrastructure are, where your power lines are. So being able to generate accurate maps of that and then run those through basically supercomputers to generate the field measurements that you'd expect to see is pretty challenging. Well, you're in an environment that you still understand where the power lines are. You still understand where the power generation plants are. So you really are expecting a stable infrastructure is what I think I heard you say. But oftentimes in war that infrastructure doesn't exist anymore. What do you think is your prognosis for the future of using a technology like this when you don't necessarily understand the infrastructure? So that's an interesting question, right? How do we update our maps when the maps changing? And that's something that I think is going to be kind of augmented by like AI in the future, for example. Artificial intelligence and machine learning. Right, exactly. So well, if you're doing this on your phone, your phone might not be able to run the full computer simulation for the continental United States. However, it can maybe run some local changes on that. So by having, for example, a faster AI informed field solver, we can actually update the maps kind of on the fly or make guesses as to how the maps should be updated. Okay, so I'm tracking you, Kevin. What I would like to understand a little more though is do you think this technology could work if soldiers were in a war environment where the power and the infrastructure was gone, the local infrastructure? Yeah, absolutely. So even though there may be no local infrastructure, 60 Hertz fields propagate for long distances and because they're very low frequency, they can even propagate through buildings. And so, like for example, power from a nearby city can still be used for navigation. We've even seen these fields in space. So what do you think about the timeline for being able to take electric fields and apply them to an assured precision navigation and timing problem? How many years away do you think we are? I think we're a few years away from seeing like a demonstration of this in like a local city area. When do you think a technology like this might show up in the hands of a soldier? Some of what we do at ARL is very future forward. So we're focused not just on the immediate impact but on impacts, you know, down 20 or 30 years out. This technology, I think, is probably more of the 15 year, 20 year technology. But we'll probably start seeing some demonstrations of that well before then. Yeah, so we're looking, you know, and that's kind of right in ARL sweet spot because ARL is as the U.S. Army's Corporate Research Laboratory. We're focused on the far term, the longer term technology with an aim of 2035 and beyond per se. Now the notion of that, of course, is that there are a lot of open questions that still need to be addressed. Most from a biomedic standpoint, many things in nature who navigate with fields use magnetic fields. But I want to ask you the question about this from a navigation point of view. Is there any inspiration that you've drawn from nature on how you might take advantage of fields to navigate? So I think the closest example would be the sharks where it's kind of an inverse problem. The sharks use the electric field to hunt down their prey instead. And actually we have some ideas for using that to, for example, avoid objects, right? Because the electric field distorts and bends around people. So while you can, you know, hide with camouflage, it's very difficult to camouflage yourself to the electric field. And so use that for, like, to keep quadcopters, for instance, from bumping into people in a crowded environment. Birds have, you know, their internal magnetic compass that they can use for navigation. But there is also, like, a spider, for example, that as it spins its silk, it electrically charges it. And then once it's got enough silk hanging out from back of it, it actually provides a lift to the spider and the spider can fly away on its own silk. And so these are kind of, you know, some of the things that we're looking forward to for applications as well is use not just the magnetic field for navigation, but the electric field for navigation as well. I think what's interesting about this is the magnetic field occurs naturally. And here we're really talking about using man-made fields, but in a similar way. So the notion that one can navigate using fields has been demonstrated in nature. The processors that these animals use, while they don't draw a lot of power, are fairly sophisticated compared to the technology that we have available. So I would assume that much of what you've said about artificial intelligence and machine learning is really why it's going to take us much longer to understand the problem and then to develop a technology that you could actually put in someone's hand. Because while it's almost trivial to sense the field, being able to understand that field, process it, put a neural network or some machine learning algorithm or some deep learning technique against it to make it useful is going to take quite a bit of research. So one of the reasons that we haven't seen this before is that while the physics is really well understood and we can model it and we know what's going on, one of the challenges with electric fields is that things actually interact with each other. So if you have one object, then you can know how that distorts the fields. But when you start putting in another object that distorts the fields that the first object sees, which then changes things, that's what's called a nonlinear process. Now as it turns out, computers aren't very good at doing that. Computers are very good at doing linear processes. But brains are really good at doing nonlinear processes. And so that's one of the reasons that we've seen this in animals is because the brain can do all of these nonlinear connections and the shark can hunt using electric fields very effectively. But AI and ML and like deep neural nets and this neuromorphic computing, those are starting to move computers towards a nonlinear process. So now we can throw those tools at it and start doing kind of nonlinear estimates of the fields and that's allowing us to do a lot of these new applications. That's very exciting. So I think that in the future you'll be able to make this connection between the physics of electric fields, the computer science associated with machine learning, deep learning, other kinds of nonlinear compute processes and to be able to bring this technology to our warfighters in a way that will help them navigate in areas where GPS is denied, the infrastructure perhaps does not exist. But we still need to get our soldiers connected together in a way that maximizes their effectiveness and allows them to maneuver around the battlefield in ways that will provide them with relative positions of advantage in the most efficient way. Let me ask you this question. What gets you excited, Kevin? What I really like about this is that this work is two things. It's doing physics in new and exciting ways. So I like, you know, breaking things. Somebody in my code is a modeling simulation expert. They give me their codes and I break it and come up with new things to do with it. The other thing is that it's, you know, applied. So the things that we're making go out and help the warfighter. We're like, removing the warfighter from harm or helping them know where they are and keep them from getting lost. And being able to see that impact actually is very rewarding. One thing I will always say is that we look to do disruptive research. That is, research that will either change the way people think about scientific paradigms or will change the way the Army uses technology to fight and win its battles. Well, Kevin, thanks for the conversation. I find your work really interesting and I know that in the long term this is going to pay off for the United States Army. So thank you for joining me today. And to all of you, thanks for joining us for ARL, what we learned today. In upcoming episodes, we'll continue the discussion about the underpinning research that will build the Army of the future. Please consider liking and subscribing. Science is a journey of discovery and we're glad you're along for the ride. For the Army Research Lab, I'm Dr. Phil Percom.