NASA'S 'POINTER' Tracks First Responders Where GPS Fails

A firefighter's precise location in a burning building can be difficult—and vital—to know. Rey Ramon/U.S. Air Force

That little blue dot likes to mock. Glowing bright on a smartphone's map, it's usually a reliable marker of the user's location. Except when it's not. Anyone who's tried to use it to navigate out of a subway station, a mall or a high-rise apartment complex can attest to the frustration of the blue dot that is just pretending to know which way they're facing or where they are (no, not in that river two blocks away). The consequences of using the wrong exit out of a shopping center are minimal, but when it's a firefighter trying to make her way out of a burning building, the stakes for tracking her precise location and orientation are high.

A system is being developed at NASA's Jet Propulsion Lab (JPL) with funding from the Department of Homeland Security (DHS) to track first responders accurately and in real time in spaces—such as buildings made of steel and concrete—where GPS and other technologies fail. The primary goal of the new system—Precision Outdoor and Indoor Navigation and Tracking for Emergency Responders, or POINTER—is to save the lives of those whose job it is to save lives.

At a fire, "it's hot and it's loud," says Xenophon Gikas, fire captain at the Los Angeles Fire Department and a member of DHS's First Responder Resource Group. He's part of a working group that has helped explain first-responders' needs and give feedback to the JPL team. As firefighters rush around, "people are screaming, saws are going off.… We have blowers that we turn on to blow heat and smoke. It's a crappy environment. It's the worst one we have," he says. "That problem of trying to find one of us who's trapped or down or lost—whoever figures that one out is going to have the holy grail in their hand."

POINTER relies on what are called magneto quasistatic fields. That differentiates it from cell phones, wireless internet, radar and GPS, all of which rely on electromagnetic waves to allow sensing or communication over long distances, explains Darmindra D. Arumugam, the principal investigator for the project at JPL. But these waves have two shortcomings as locators: They offer relatively coarse localization and, even if they are able to penetrate through structures, which they often can't, they bounce off walls and become maddeningly inaccurate.

"One of the things we noticed is that if we generate a magnetic-only field," Arumugam tells Newsweek , it is "largely unperturbed by most structures." In other words, unlike gadgets that use electromagnetic waves, POINTER doesn't lose its mojo, or accuracy, around people, objects or walls. So it can be used for "navigation and tracking in environments where traditional devices don't work." Consider it a victory over the infuriating blue dot.

POINTER's primary limitation is distance. Even though it generates a magnetic -only field that can be used for tracking without being perturbed by walls or people , the motion of charges in the air will inevitably create an electric field and then the magnetic and electric waves will become strongly coupled as electromagnetic waves. At that point the same problems would arise as with technologies like GPS. So POINTER can only work in the short range before that happens.

The current iteration of POINTER is the size of a shoebox and weighs about 3 pounds; first responders can carry it like a backpack. It generates a magnetic field that can be detected by another device nearby (perhaps mounted on a firetruck). The receiver must be placed within that short range in which the magnetic field is dominant, before the electromagnetic waves win out. Though the exact interval can be manipulated by using different frequencies, Arumugam says, POINTER works best at a maximum distance of hundreds of yards, up to about 1,000 yards. It can determine where the first responder is, including elevation, and whether he is still or moving, standing straight up or facing the ground, based on the position and orientation of the mobile device.

The current iteration of POINTER is the size of a shoebox and weighs about 3 pounds, allowing first responders to carry it like a backpack. Paul Wedig/DHS-Science and Technology Directorate

The basic technique isn't entirely new, says David Ricketts, an associate professor in North Carolina State University's electrical and computer engineering department. He worked with Arumugam several years ago on a project that looked at a sports application of magnetoquasistatic position and orientation tracking, specifically following a football in play. That version of the technology could only work outdoors. He cites a group of Italian researchers who published a paper in 2014 describing a magnetic indoor positioning system and the company Polhemus, which has used similar physics for a few decades. However, he says Arumugam has simplified the measurements and calculations involved using a new antenna and reduced limitations on accuracy and orientation.

The "use of these low-frequency magnetic waves is a really promising solution for buildings and finding people in obstructed areas," Ricketts says. POINTER has the potential to remove many of the obstacles of limited visibility, he says, since it can "see" through smoke, fire and even many nonmetallic walls. "Still, I think the technology has some challenges." These include the need to calibrate the system before use, the potential impact of certain building materials (Ricketts says metal, for example, could cause errors, whereas wood would not) and, most of all, the ability to shrink the devices. But all of these issues could be solved, he says, especially by this team. "Darmin is super talented," he emphasizes, and has already made vast improvements.

The JPL team is working on making the transmitter lighter and smaller (until it can fit in a pocket or on a belt buckle), increasing resolution, honing the tracking of multiple devices and making the update time even faster. Field trials aren't scheduled to start until sometime after October 2018, but if that goes well, Arumugam says, he hopes it will be integrated quickly in fire departments across the country. Police departments and the military could potentially also use POINTER-like technologies, when responding to emergencies or in urban combat situations. Other potential applications include uses in the aftermath of natural disasters, underground exploration of mines, commercial uses (like tracking robots in warehouses) and in subsurface robots in space, such as in the water and ice of Europa.

The "old school" method of tracking first responders is basically having "firefighters chasing other firefighters," says Gikas. Though there are aspects of POINTER that could be improved, it is "orders of magnitude better than what I have today," says Gikas. "It's better than anything I've seen."

Joshua Dennis, district chief at the Chicago Fire Department and chair of the First Responder Resource Group, is similarly optimistic. "What they showed us in terms of the elegance and its simplicity, it was amazing. I was impressed, and actually that's not easy to do," he says. "Other demos of similar types of technologies did not go that well." Dennis tends to be skeptical when engineers are showing him new gadgets, sometimes throwing them off the roof to see if they break before he sits for a full presentation. But at a recent demo of POINTER, "they took it and went all over JPL's campus. It met the one thing that nothing's been able to do yet: basic competency of telling me what floor are you on and where are you at," he says. "It's the most promising breakthrough we've had yet."