Q-Track Corporation won the RFID Journal Live "Coolest Demo" Award for our indoor location system which tracked the real-time location of an AR parrot drone flying around the Exhibit Hall floor.

The last couple of weeks were action packed. Two weeks ago, I spoke at the Texas Wireless and Microwave Circuits and System Symposium at Baylor University in Waco (see my post “Demystifying Electromagnetic Superposition“). Last week, I joined the Q-Track team in Orlando for RFID Journal Live, our industry’s leading trade show. Q-Track came home from the show with the “Coolest Demo” award enabled by our remarkably precise NFER® indoor location system. In this post, I’ll share some of the story behind what we did and how and why it worked.

I arrived the night of Monday April 7, because I was scheduled to deliver a tutorial on Near-Field Wireless Technology to the folks at the co-located 2014 IEEE International Symposium on RFID Tuesday afternoon. That night, I got the word that the rest of the Q-Track team, our CEO Steve Werner, and our new Marketing Director, Chad Ludwig, would be delayed due to weather-related flight disruptions. They would not be able to arrive until an hour or so after the show’s opening reception, so the burden was entirely on me.

I spent Tuesday morning getting our booth set-up and our demonstration system deployed. It took me about an hour to unpack all our boxes and set up the pop-up booth backdrop. In another hour, I was able to get three receivers deployed in and around our booth and connected to the laptop computer that would be our tracking server. It took me a little more than an hour to walk around the tracking area taking calibration points to characterize the signal perturbations caused by the tracking environment – principally the building structure and the wiring. Then I confirmed that the system was working properly by walking around the tracking area with several NFER® Tag Transmitters deployed around my belt and the “history trails” function enabled to leave a trail on the screen. When one of our indoor location systems is working properly, you can see the difference in location of the “left” and “right” tags by observing the slightly offset paths in the tracking display. Everything checked out perfectly. Although the job would have been faster and easier with help, it wasn’t beyond the ability of a single person to get the Q-Track NFER® RTLS system up and running in relatively short order.

Q-Track CEO Steve Werner drives an AR Parrot Drone around the RFID Live Exhibit Hall floor while an NFER® RTLS tracks the drone's position to 40cm rms accuracy or better.

I ran off to get changed – the organizers do not turn on the AC in the Exhibit Hall until just before the show starts – I had lunch, and I presented my tutorial. Finishing a bit early, I returned to our booth in the Exhibit Hall to fire up the demonstration.

This has always been a moment of some trepidation. At the first show Q-Track attended way back in 2006, we had a beautiful demo set up and calibrated with some of our earliest prototype equipment. We shut everything down, and then turned it all back on right when the trade show opened up. The tracking showed embarrassingly large errors. I had to hurriedly recalibrate the system while my colleagues distracted our potential customers. Finally everything worked again, and we could show it off. But then a while later, tracking would deteriorate again, requiring another panicked round of recalibration. We spent half our time at the show tracking, and the other half recalibrating the system. In retrospect, we were being bit by thermal drift. Our system relies on very precise phase and amplitude measurements. Electronic circuits behave a bit differently when first turned on, i.e. cold, than they do after they’ve been running for a while, i.e. hot. Between the variations in tags and receivers, it was tough to get consistent performance for more than an hour or two at a time.

But with several generations of hardware improvements and years of additional experience under Q-Track’s collective belts, those days are behind us. When I fired up the demonstration system for the opening reception of RFID Journal Live, everything worked perfectly – exactly the same as when I’d last checked it that morning.  We advertise 40cm rms accurate tracking. Our demonstration was probably delivering even better than that, although I was too busy to perform a detailed accuracy check.

Q-Track's QT-701 Tag Transmitter weighs in at only 50 grams (~1.6 oz), yet delivers that same 40cm rms accurate indoor location capability of Q-Track's ruggedized industrial-strength NFER® RTLS tags. This photo shows one of the first prototypes.

Not long after the Opening Reception began, Steve and Chad arrived to help me handle the crush of opening night visitors interested in our demonstration and curious about our products. In fact, we were so busy that Steve didn’t get a chance to try out the drone until the next morning. The Parrot AR.Drone Quadricopter survived shipping and worked well. The control datalink for the drone requires a 2.4GHz wireless connection. With so many vendors trying out their wireless products, it was difficult getting a reliable connection. Steve’s demonstration worked best at the beginning and end of each day’s session when interference was at a minimum.

The technology that enables the The Parrot AR.Drone Quadricopter is remarkable in and of itself, but what made our demonstration really fly was Q-Track’s new, lightweight QT-701 Tag Transmitter. Weighing in at only 50 grams, the QT-701 Active Tag enables the same 40cm rms accurate tracking as our larger, more ruggedized industrial tracking tags, but in a compact form-factor suitable for everyday office use.

The other remarkable feature of our demonstration was its robustness. We were up and tracking for the entire duration of the show with no more than a momentary interruption. Naturally, that’s what you’d expect from a commercial indoor location system. But obtaining that kind of reliability is extremely difficult in the hostile RF environment of a trade show. With so many vendors operating so many devices, reliable wireless links are challenge to maintain, if they can be established at all. In fact a couple of our much larger competitors had much larger footprints and much fancier displays on the trade show floor. But neither was able or willing to try to demonstrate a working location system at the show. I think that fact was influential in the decision making behind the “Coolest Demo” Award.

Q-Track’s “Near-Field Electromagnetic Ranging” (NFER®) indoor location systems offer an effective, if unconventional, solution to many indoor location problems. My Q-Track colleague and co-founder, Bob DePierre, and I came from an ultra-wideband (UWB) RF background. We saw first-hand how UWB location systems could be quite accurate with a line-of-sight between a tag and a receiver, but as soon as the direct path was blocked, accuracy began to degrade. Try to go through a wall or two, and it becomes very difficult for a UWB system to get a good fix on your location. Short-wavelength and high-frequency microwave systems work great if you need to send lots of data, but location systems just require getting a signal through a complicated and cluttered environment with minimal distortion or degradation.

Bob and I left our then employer to pursue a different path. We reasoned that low frequencies were the way to go. Low-frequency, long-wavelength signals bend around or penetrate through obstructions much better than comparable high frequency signals. And when the wavelength is much longer than the distance of the link, you don’t get the kind of cancellation and fading you see in high frequency short wavelength signals. I discovered a variety of techniques for using “near-field” physics in localization, and Bob reduced them to practice by building the hardware to prove that my ideas would work. In a matter of a few months, we had a prototype that could track a little red wagon up and down Bob’s driveway to an accuracy of a few inches.

Today, our NFER systems operate at around 1MHz under FCC Part 15 rules for unlicensed low-power transmitters. With a wavelength of 300m, they deliver 40cm rms accurate tracking. Typical ranges are around 15-20m (45-60ft). In a particularly noisy environment (like the Exhibit Hall) range may be as short as 10m (30ft). In really quiet settings (like many retail or warehouse environments) range may be up to 30m (100ft).

The Orange County Convention Center in Orlando housed the 2014 RFID Journal Live trade show.

Below is a great screenshot of our NFER® indoor location system in action. We deployed three QT-555 Locator-Receivers and we were tracking about a 40ft x 60ft area around our 10ft x 10ft booth with the 40cm rms accuracy typical of NFER® real-time location systems. The system can accommodate up to 84 tags simultaneously at a 1Hz update rate, but we were never using more than four or five at a time. You can see solid, repeatable tracking on the inside loop of me (blue trail), Chad Ludwig (orange trail), and Steve Werner (green trail). Note the head shot “avatars.” I looped the outside edge of the tracking area – you can tell the system was having some difficulty because the update rate slowed down a bit (i.e. the space between the blue dots showing the location fixes got bigger). Finally, I walked the perimeter of three 10ft x 10ft squares and their diagonals to highlight the precision of our tracking. Ultimately, our system ran for the duration of the show with no tweaking or adjustment needed.

Screenshot of Q-Track's NFER RTLS indoor location system GUI. The colored lines show history trails as we tested the system the morning of April 10.

 In the final hours of the show, we heard an announcement that the Awards Ceremony was beginning. While we were excited about how well our location system was performing, the broader world of RFID encompasses many other interesting and useful applications. And no one from RFID Journal had been by to hint that we needed to attend. Chad and I were surprised when someone came by to tell us we’d won. By the time Chad could get to the stage, Steve, who had been walking back to us after meeting with a potential customer, arrived to collect the award. Chad captured this shot of Steve holding the award and me holding the drone.

Steve Werner (left) displays the 2014 RFID Journal Live "Coolest Demo" award. Dr. Hans Schantz (right) holds the Parrot AR.Drone Quadricopter. The QT-701 tag is mounted on top of the drone.

 The show ended at 3pm on Thursday. We broke down the tracking demonstration and the booth and flew home that night. I made it home around midnight.
Now we’re looking forward to the challenge of an even cooler demo at 2015 RFID Journal Live in San Diego. What would you propose we do with a robust accurate tracking system on the Exhibit Floor of a trade show? Leave your ideas and suggestions in the comments.

The Q-Track gang is in Orlando, Florida this week  for RFID Journal-LIVE, the world’s premier conference and exhibition focused on radio frequency identification (RFID) and its many business applications. The tradeshow is underway April 8-10, 2014, at the Orange County Convention Center, located in Orlando, Florida. More about that later.

Our week kicks off with my tutorial at 1pm Tuesday, April 8 on “Near-Field Wireless Technology” at the co-located 2014 IEEE International Conference on Radio-Frequency Identification (RFID). This technical conference, sponsored by IEEE – the world’s largest professional association for the advancement of technology – highlights leading-edge advances in RFID technology. I will discuss the origins of near-field wireless, survey applications, present near-field links laws, and discuss the properties and performance of electrically-small antennas. Near-field wireless technology is an emerging area of great importance in RFID. Specific applications including low frequency (LF) and high frequency (HF) RFID, Near-Field Communications (NFC), RuBee (IEEE 1902.1), wireless power transfer, and Near-Field Electromagnetic Ranging (NFER). My tutorial will earn attendees 3 IEEE Professional Development Hours (PDHs). Lunch and coffee breaks will be provided. IEEE is charging $100 for the tutorial or $150 if you take my tutorial and one of the ones offered in the morning.

Slides for my Near-Field Wireless Technology workshop are available at the link.


The five pointed star is a symbol of Texas and the Texas Symposium adopted it as their own as well. By courtesy and permission of Jollie Primitives. Click to order your own.

This afternoon I will be presenting an invited talk at the 2014 Texas Symposium on Wireless & Microwave Circuits & Systems at Baylor University in Waco, Texas. In my talk, Demystifying Electromagnetic Superposition (slides), I will examine the interesting behavior of electromagnetic waves when they superimpose or interfere with each other. I have a paper on the subject that I will share soon.

Mar 312014

Blogging has been taking a back seat to everything else in my life, lately. This week, though, I have a variety of interesting and exciting developments to share. Today’s news is an update on the indoor location company I co-founded, Q-Track.

The good news began a few month ago in November with a favorable mention in IEEE Spectrum Magazine, the flagship publication of the Institute of Electrical and Electronics Engineers. An article surveying solutions to the challenging problem of indoor location noted:

“One company offering help with that is Q-Track, based in Huntsville, Ala., which claims its indoor radiolocation system can provide submeter accuracy. It uses frequencies of about 1 megahertz, which is considerably lower than Wi-Fi. Why? “You want to have a signal that can get through a messy propagation environment,” says Hans Schantz, cofounder of Q-Track. Low frequencies can more easily penetrate the many barriers found indoors. They diffract less around obstacles, and they don’t fall prey to the multipath phenomenon, whereby the different waves caroming around inside a building interfere with one another.

“Q-Track’s system differs from Wi-Fi localization in another fundamental way: It doesn’t use signal strength to gauge the distance between transmitter and receiver. Nor does it measure the time it takes the signal to travel from transmitter to receiver, as GPS does. Instead, it cleverly exploits the fact that at frequencies of a megahertz or so, and at building-size distances (say, up to 100 meters), the receiver operates in what radio engineers call the near field of the transmitter.

“In this special zone, the emanations from a radio antenna are rather peculiar. The electric and magnetic fields do not rise and fall in lockstep, for example, as is normally the case with radio waves. And the difference in their timing (their relative phase) is, conveniently enough, a function of the distance from the transmitting antenna.

“Q-Track uses the distance-dependent difference in phase, as well as other features found only in the near field, to calculate the location of a transmitter tag with respect to fixed receivers. Those receivers are fitted with antennas that can separately measure electric and magnetic fields. Outdoors, the system is accurate to 15 centimeters, but indoors, the structural elements of a building produce errors of as much as several meters. But by mapping out the site’s radio environment first, says Schantz, the system can locate one of its tags indoors to within 40 cm.”

The article, “New Indoor Navigation Technologies Work Where GPS Can’t,”  is available here.

All of us at Q-Track have been working diligently to increase the accuracy, performance, and reliability of Q-Track’s Near-Field Electromagnetic Ranging or “NFER®” Real-Time Location Systems (RTLS). That hard work paid off in December when Lockheed-Martin awarded Q-Track a $1.7 million contract to track soldiers in an urban operations training range:

Now, of course, we’re all having to work even harder – making sure we complete our order and deliver it on time. The increased visibility resulting from all this good news made us realize that our old website was simply not up to the demands of accurately presenting Q-Track’s product offerings and indoor location applications. This past month I undertook a complete Q-Track website renovation, including updating the website and its content to a fully responsive and adaptive WordPress template.

Finally, at lunch today I’m presenting a dry run of a workshop on Near-Field Wireless Technology, sponsored by the Huntsville Section of the IEEE. Near-field wireless technology is an emerging area of great importance in Radio Frequency Identification (RFID). Specific applications include low frequency (LF) and high frequency (HF) RFID, Near-Field Communications (NFC), and Near-Field Electromagnetic Ranging (NFER). This workshop will discuss the origins of near-field wireless, survey applications, present near-field links laws, and discuss the properties and performance of electrically- small antennas. Today’s session is a practice run for the three hour version I’ll be presenting next week at the 8th Annual IEEE International Conference on RFID.


This insightful piece from the Huffington Post describes how the friendship of electrical pioneer Michael Faraday and landscape artist J.M.W. Turner influenced Turner’s work - Mario Livio: When Science Met Art.


The Czarina and I are finally moving on up. The bungalow that was merely “snug” when we only had one set of twin girl babies has become a raucous and cramped madhouse now that the eight-year-old girls have been joined by their four-year-old brothers. We scrutinized our finances, consulted with our lenders, and decided to hold on to the old house, build a new house, then clean-up and sell the old house. We could just barely swing the dual mortgage payments. The problem was coming up with the down payment for the new house while holding on to the old house. Fortunately, we had a Home Equity Line of Credit (HELOC) from Bank of America, so we’d be able to borrow against the old house to raise the funds to pay for the new house.

Or so we thought.

Continue reading »


Here’s more good press for NFER® RTLS pioneer, Q-TrackNuclear Engineering International reports:

Workers in six US nuclear power plants are being trained in a virtual radiation environment so that they can develop skills to keep radiation exposures low.

The Q-Track radiation worker training system combines a software program that can be used to define a virtual radiation zone with an indoor wireless tracking system that monitors trainees’ movements. When a trainee approaches a ‘virtual’ radiation source within the simulated radiation environment they will receive a realistic dose, rate and alarm from their simulated electronic dosimeter. Q-Dose also tracks the cumulative dose incurred during the training process. Software can be used to record the trainees’ responses, creating a radiation trail mapping their movements. Instructors can later replay this location, dose and rate data so that trainees can review and critique their performance.

This video shows the Q-Track Dosimulation™ system in action:

Southern Company’s Plant Vogtle won a Top Industry Practice or “TIP” Award from the Nuclear Energy Institute for piloting the Dosimulation™ system. For more information, visit the Q-Track website.


Employing Q-Track’s patented Near-Field Electromagnetic Ranging (NFER®) technology, Collision Avoidance Non-Line-of-Sight (CANLOS™) systems allow robots to detect and avoid colliding with their human co-workers even when when direct line-of-sight may be blocked. NFER® signals use low frequencies that penetrate better and diffract around obstructions that may block conventional RF and optical sensors. This non-line-of-sight behavior makes NFER® products well-suited for use in complicated industrial settings.

How CANLOS Works

A leading manufacturer of innovative motion control and automation equipment for industry, CAMotion, uses Q-Track’s CANLOS™ System to provide non-line-of-sight awareness to robotic cranes, helping them to stop safely before colliding with their human co-workers. RFID Journal recently described the successful system in a feature story:

CAMotion is providing the CANLOS system—as redundancy to its laser-based collision-avoidance technology—to a magazine printing firm that utilizes automated cranes to move large stacks of paper, known as logs. The CANLOS system has been installed at 15 locations throughout the United States, according to Alex Furth, CAMotion’s CEO, with six additional sites slated to go live during the next few months. 

Workers wear a QT-600 Tag Transmitter that not only allows the CANLOS™ receiver to detect their proximity, but also supports real-time location awareness in a more general NFER® Real-Time Location System (RTLS). The RFID Journal article explains how Q-Track’s CANLOS™ system works in detail:

A Q-Track QT600 RFID transponder, worn on a belt clip, beacons a unique ID number at predetermined intervals—typically, 10 times per second. The RFID receiver is installed on the crane’s gripper (the claw that picks up an item), which measures about 45 inches in length and 9 inches in width. The crane itself usually moves at the speed of a typical fast walk. When the gripper comes within about 8 feet of an individual’s transponder, the receiver determines that a collision is possible. The CAMotion software, loaded on the machine’s onboard computer, then instructs the crane to halt, which takes approximately 1.5 seconds to occur once the transmission has been received.  

Here’s a close-up of the CANLOS™ receiver installed on the crane’s gripper:

Close-up view of Q-Track's Proximity Detection System (CANLOS) (courtesy CAMotion and RFID Journal).

And here’s a view of the system in a magazine printing facility:

Q-Track's CANLOS system helps CAMotion's robotic cranes to detect and avoid their human co-workers in this magazine printing facility (courtesy CAMotion and RFID Journal).

For more information, see these additional links:

May 022012

I bought one of these Velocity Micro T301 7” Cruz Tablets and I think it’s a great value at $60. Seriously under-powered for high performance Android apps, it’s still perfect as a book reader, web browser, e-mail reader, or even for listening to music (through headphones, not the wimpy speakers) or watching YouTube and other non-flash media. Woot is a one-deal-a-day commerce site, so act now if you want one. Enjoy!


Q-Track’s A-Team traveled to upstate New York the other day to show off NFER RTLS for tactical training at Tactical Conference 2012. Here’s the press release:

May 01, 2012 - 
Verona, NY – Q-Track Corporation, the pioneer in Near-Field Electromagnetic Ranging, will demonstrate NFER Real-Time Location Systems (RTLS) products in and around Booth 515 at Tactical Conference ‘12  today through May 3 at Turning Stone Resort in Verona, NY.

The high accuracy and low cost of  NFER RTLS products allow Q-Track’s Dosimulation™ Systems to provide unprecedented realism in simulated dosimetry and radiation worker training. Now NFER RTLS is available in products suitable for Military Operations Urban Terrain (MOUT) training or for other tactical training applications indoors, underground, or anywhere GPS is not available. NFER RTLS may be deployed as a stand-alone system in support of after-action reviews, or integrated for use in other training systems.

In a demonstration at a MOUT training range, Q-Track deployed four QT-550 Locator-Receivers to track tags to a typical accuracy of 30cm-1m within a 50m x 50m (165ft x 165ft) city block, including in and around three buildings.  A video is available below:

About Tactical Conference 2012:  Sponsored by the New York Tactical Officers Association (NYTOA) and New York Association of Hostage Negotiators, the 6th annual Tactical Training  Conference and Exposition is a culmination of what the NYTOA is all about: training, sharing  information, and networking with peers and companies who make tactical officers’ jobs safer and more effective. The program brings together an exceptional instructor cadre, conference training agenda, and vendor show. Visit http://www.nytacticalexpo.com/ for details.

About Q-Track and NFER RTLS: Q-Track, a privately held company located in Huntsville, AL, has been pioneering NFER technology since 2002. Q-Track’s NFER technology is the basis of the Dosimulation system piloted at Southern Company’s Plant Vogtle nuclear facility. RFID Journal recognized the breakthrough nature of Q-Track’s innovative NFER RTLS offering with a “Best-In-Show, Finalist,” designation for the third annual RFID Journal Awards. The Nuclear Energy Institute awarded Southern Company the 2010 Top Industry Practice (TIP) Award for Training for their use of Q-Track’s NFER RTLS-based “Dosimulation” system. Q Track’s NFER RTLS is also employed in a proximity detection system and other location awareness products. For more information, visit the company’s website at http://www.q-track.com. “NFER” “Dosimulation” and “Q-Track” are trademarks or registered trademarks of the Q-Track Corporation.

© 2010-11 Hans Schantz except as noted. Suffusion theme by Sayontan Sinha

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