Measuring Micrometers: Discovering a Higher GPS

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GPS can guide you across the city or across the country and navigate dusty back roads as easily as six-lane highways. But as anyone who accidentally drove into a lake can tell you, GPS isn’t perfect. For example, it cannot keep you in a certain lane or dodge nearby cars or steer you through an exit. That’s why John Deere built a better system.

Yes, this John Deere.

You see, the GPS system most people know about was developed in the 1970s, and for what it is, it is truly remarkable. A network of 24 satellites that have been working more or less continuously for 27 years? Orbit the globe from the cold expanse of space – watch endlessly and lend a polite hand? Free? Wonderful. But it was designed to replace paper maps, which rarely measure to the centimeter. Autonomous cars don’t just need to know you’re on Highway 61, they need to know exactly where you are (at 75 mph, no less). Autonomous drones and tractors for agriculture have sparked a rural renaissance called precision farming – and it takes precision to work.

To increase this level of detail – and to revise the system in general – researchers have worked to replace the existing satellite fleet with a new iteration called GPS III. Last week, SpaceX took a step forward when it finally launched a fourth satellite into its star bed. It’s a long process: Lockheed Martin published a brief history of their GPS upgrade efforts in 2012, and we’re just getting started. The whole thing is slated for completion in 2023, at a cost of nearly $ 6 billion.

Can the private sector do better? To get some insight into what could replace GPS, we spoke to two companies that run the fee and are developing alternatives.

How Deere Made a Better GPS

Before we point out its shortcomings, let’s keep in mind that GPS is a fantastic system. Indeed, it is difficult to grapple with the ambition and audacity of the existing satellite constellation. Imagine the challenges behind introducing a precision antenna that cost a few hundred million dollars and is shaped more or less like a Mister Softee ice cream van. To complete the deed, the military hits her on a missile that burns 2,700 pounds of liquid oxygen per second, ejects her into space at Mach 1 … and then carefully releases her into orbit about 13,000 miles away. Remember, the diameter of the earth itself is only 7,900 miles.

Now imagine the algorithms and calculations required to keep them in precise orbit, never hitting the other satellites, constantly transmitting, batteries never failing, clocks that barely get out of sync when the Months turn into years and you will get the point. It’s an enormous achievement. However, it is not enough.

John Deere

In theory, GPS is accurate to within 3 feet, but in reality it’s closer to 15 feet or so – good enough to get you to the grocery store, but barely accurate. For example, if you’ve planted two heirloom tomatoes and some cucumbers in your garden, it’s easy to grow your tiny crop without knowing where to water. When you’re planting hundreds of acres, tiny telemetry errors can ruin you.

“The old days of work all day and maybe dad is ready and coming home to the son or daughter? That’s pretty much done, ”Al Savage, StarFire Network Manager at John Deere, told Digital Trends. “What farmers want is more yield. Accuracy with row planting, spraying, etc so you don’t run over your crop. “

According to NASA (yes, this NASA), when a farmer traverses a field and pulls a seeder, plow, or other equipment behind a tractor, the rows generated overlap by about 10 percent. This means that a significant portion of the field is receiving twice as much seeds, fertilizers and pesticides and the work is taking longer than necessary. Today’s tractors use digital positioning systems like your car, but require an entirely different level of accuracy. With the help of the space agency, John Deere built a better system.

John Deere

“Differential GPS is what they call it,” said Savage. To get the detailed positional data that modern farmers need, Deere built a number of ground based reference locations around the world to collect a second set of positional data, a large amount of data that the company transmits, and warehouses in two main data centers. This information is transmitted to a number of geostationary satellites operated by Inmarsat (John Deere rents space on them), and then sent back to the company’s StarFire receivers using local tractors – a round trip that takes longer than the globe, but takes about as long as a single breath.

“You speak of 12, 13,000 miles, and in some cases 20,000 miles. And it happens in five seconds, so you can imagine how fast it is and how much data is flowing, ”said Savage. The time it takes for a signal to travel from GPS satellites to Earth, combined with clocks in orbit that are easily out of sync and signal noise from electrically charged particles in our atmosphere, makes existing GPS data inaccurate. By networking the satellite data with data from its terrestrial network, Deere can triangulate the location much more precisely.

“When you spray, you want to be precise and precise. This saves you herbicides, fungicides, pesticides and sprays, ”explains Savage.

How 5G finds a way

If you read any technology site these days, you’ve heard the hype surrounding 5G. The fast new cellular network offers a number of advantages, the most important of which is speed. Qualcomm has demonstrated maximum download speeds of around 4.5 gigabits per second and average data transfer speeds of around 1.4 gigabits per second. That’s fast enough to download a two-hour movie in about 17 seconds, versus about 6 minutes for a current 4G connection. In other words, new 5G phones are around 1,000 times faster than the phone you currently have in your pocket.

But 5G is more than just phones: Qualcomm believes that with 5G, tomorrow’s cars will talk to each other and you will all oversee them all by yourself. To do this, Qualcomm’s chips do more than just transfer data faster. They support CV2X communication (Cellular Vehicle-to-Everything), which enables direct communication between cars and other intelligent objects in the infrastructure of a city.

A little discussed part of Qualcomm’s automotive plans includes building a system to eliminate the 3 to 15 foot precision problem of GPS. For this purpose, the company relied on its existing patent portfolio. It merges data from existing satellites of the Global Navigation Satellite System (including GPS, Europe’s Galileo, Russia’s GLONASS, etc.) with something called VEPP or Vision Enhanced Precisioning. Essentially, Qualcomm plans to use images from existing video cameras to pinpoint the exact location of a car.

“The cost of this is not astronomical,” Nakul Duggal, senior vice president of product management at Qualcomm, told Digital Trends. “You basically need a standard camera like today … everything else is something you already activate the telematics unit for.”

An illustration shows VEPP data in combination with conventional GPS data. Qualcomm

But here’s the thing: CV2X has been a dream among tech companies for years, and while promising, it also poses challenges. For one, there’s the problem of finding the bandwidth: regulators reserved some of the spectrum at 5.9 GHz for vehicle-to-vehicle chatter, but the regulatory effort to get the project going literally went nowhere. Ajit Pai, chairman of the Federal Communications Commission (FCC), wrote last month: “The 5.9 GHz spectrum has been idle for far too long. For the past two decades, the people of America have been waiting for this premium mid-band spectrum to be used, and the wait is over. “

No, Americans didn’t ask for it despite Pai’s excitement. Few people think twice about the frequency distribution between breakfast and bed. However, the FCC’s move last month to modernize the 5.9 GHz band is good news for C2VX. Still, 5G has a long way to go in cars.

In addition, the sluggish 5G timeline has been edited. The first 5G modems could appear in new vehicles in 2022, and advanced models are unlikely to arrive until 2025, according to Light Reading. The roadside infrastructure for communicating with these modems to enable self-driving is not expected to become commercially available until 2025. Meanwhile, John Deere’s StarFire system is already working on 5G, Savage said along with GPS, Russia’s GLONASS, QZSS, IRNN and others. If 5G is widespread, it will help fill a number of gaps.

“5G will be very helpful when it comes to farmers in rural areas at higher latitudes – in the EU, in the Netherlands. I think 5G will help. Anything hilly, where the vehicle’s stance, the unevenness of the terrain where you can’t really see the south end for satellite coverage, 5G will really help too, “said Savage.

Here’s one point to highlight: GPS III, 5G, and StarFire are not necessarily competing technologies. No single company or technology will, and does not have to, dominate this area and make the others obsolete. It’s important to note that 5G will improve, not replace, John Deere’s Starfire system. GPS III will work with – and not against – 5G to keep autonomous cars on course. They are all different paths that lead to the same goal: Better positioning for everyone and everything, regardless of the application.

See you? Avoid the lakes and keep both hands on the steering wheel. Because a new GPS is just up the road – but we can only get there that fast.

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