How accurate is GNSS, and what’s behind it? Emlid CEO Igor Vereninov explains centimeter-level positioning

Centimeter-level positioning once required bulky, expensive gear. Today it’s in your backpack.
This story is drawn from the MapScaping Podcast episode with Igor Vereninov, CEO and co-founder of Emlid. He shares how GNSS went from inaccessible to indispensable, what’s under the hood of high-precision devices, and bonus answers to some out-of-the-box questions about the future of GNSS. 

Why GNSS became affordable and why that matters?

Ten years ago, high-accuracy GNSS receivers were almost exclusively expensive, specialized tools used in surveying and construction. Today, those top-tier systems still exist, but they now share the market with a growing range of compact, cost-effective receivers that deliver professional-grade performance at a fraction of the price.

Emlid recognized the opportunity and took a different approach, combining open-source software with emerging hardware to create an accessible, compact receiver.

“We saw the components were there: open-source software, affordable chips. But no one packaged it into a usable product. That’s what we did with Reach,” Igor Vereninov recalls.

This innovation arrived just as autonomous vehicles and mapping drones were gaining momentum, creating demand for accurate yet affordable positioning technology. Modern GNSS tech met that need.

In just a few years, the wider availability of precision GNSS has opened up new possibilities across industries—from mapping and agriculture to construction, GIS, and beyond—where centimeter-level positioning is now within reach.

Accuracy vs. precision: what’s the difference?

When discussing highly accurate data, it’s important to clarify common terminology. A key distinction often missed is the difference between accuracy and precision.

Accuracy is how close your measured point is to its true position. Precision, on the other hand, is about consistency: how closely repeated measurements align with each other.

Let’s connect this to real-world workflows. Surveying a property boundary requires both high accuracy and precision. However, for tasks such as measuring stockpile volume, repeatable relative measurements may be more important than precise absolute accuracy. Understanding the demands of your use case helps tailor your GNSS setup accordingly.

What level of accuracy can GNSS achieve?

This brings us to a common question: how accurate can GNSS really get? The short answer is centimeter-level, but only under the right conditions.

Smartphones, even the most advanced ones, typically provide accuracy within 3–5 meters. That’s fine for navigation, but insufficient for mapping or surveying. Professional GNSS gear, by contrast, can pinpoint your position to within 1-2 centimeters. The secret lies in techniques like RTK (Real-Time Kinematic) and PPK (Post-Processed Kinematic).

Both techniques use two GNSS receivers as a stationary base station and as a moving rover. In RTK, a base station sends real-time corrections to the rover to refine location data instantly. PPK doesn’t require a real-time link between the base station and the rover. To improve measurement accuracy, the data is processed after the survey using post-processing software. Both methods dramatically increase accuracy compared to standalone GNSS use.

What is inside a GNSS receiver?

Of course, accuracy isn’t just about software: hardware plays a crucial role. The performance gap between smartphones and professional GNSS receivers comes down to what’s inside.

High-precision GNSS receivers like the Emlid Reach series rely on specialized chips that can receive multiple signals across various frequencies from each satellite, unlike standard smartphone chips that only capture one signal per satellite. 

But it’s not just about the chip—the whole system has a few important parts: a strong antenna to catch clean signals, a receiver that turns those signals into raw data, and a processor that figures out your exact position. 

The antenna is especially important. It needs to pull in strong, clear signals and stay reliable no matter where the satellites are in the sky. To do this well, the antenna is usually about the size of a small plate. Inside, there’s a tiny point—called the phase center—where all the signals come together. This spot has to stay stable, down to the millimeter, to keep the positioning accurate.

Can smartphones replace GNSS receivers someday?

With all the advances in consumer technology, it’s fair to ask—will smartphones ever catch up? Given the importance of specialized chips and antennas in high-precision GNSS, the answer is: not anytime soon.

Despite ongoing software improvements, smartphones face fundamental hardware limitations—small antennas, limited GNSS chip performance, and a lack of precise calibration. Overcoming these obstacles would require a complete redesign of smartphones with positioning as the core priority—an unlikely direction for devices built primarily for general consumer use.

How deeply do we now rely on GNSS?

GNSS powers more than maps—it’s critical infrastructure for logistics, finance, emergency services, and precision farming. To fully grasp the true impact of GNSS, consider what happens when it stops functioning. 

“We really rely on this infrastructure. I like the term of global utility because it’s really the utility immensely useful for so many things all over the world. And when it goes down, even in some regions, then it causes a lot of trouble,” Igor Vereninov explains.

In April 2023, farmers across New South Wales and Victoria reported that their machinery became inoperable without the precise GPS guidance, forcing some to revert to manual methods or less accurate systems. The incident highlighted how deeply we are now dependent on GNSS systems.

When a satellite stopped broadcasting the signal and the tractors couldn’t drive, the farmers just couldn’t farm. And that’s also wild that we have something in space, and if it breaks down, we can’t grow food for ourselves,” Igor says.

Even wilder: can GNSS handle drifting continents?

Yes, Earth itself is moving. Continents shift by centimeters every year. In places like Australia, this amounts to 7 cm annually—a significant challenge for systems that rely on fixed coordinates.

For regions experiencing gradual tectonic drift, RTK GNSS systems offer a reliable solution. Since both the base station (or local reference station) and the rover move together with the tectonic plate, their relative positions remain consistent over time. This means your measurements won’t slowly drift year after year, ensuring long-term accuracy in critical applications like boundary surveying and infrastructure planning.

What’s the future of GNSS: will visual positioning replace it?

Visual positioning is an emerging technology to figure out where you are by using a camera to compare what it sees around you with a stored 3D map. This method can work well in cities where there are lots of buildings and landmarks to recognize.

However, in most places outside a city, like forests, mountains, cornfields, etc., visual positioning is challenging. There just aren’t enough unique features to help the system figure out your exact location. In these wide-open areas, GNSS is still the best option.

So, visual positioning won’t replace GNSS—it will work alongside it. Visual tools can help in cities where satellite signals can be weak, while GNSS will continue to be the best choice in open areas, and even in the air or at sea. Together, they make location tracking more reliable everywhere. For global, reliable, and centimeter-level accuracy, GNSS is here to stay.

GNSS to guide you no matter where you are

It’s astonishing when you think about it. Satellites orbiting 20,000 kilometers above Earth help us locate ourselves within a centimeter. Thanks to innovations, this technology is now accessible to surveyors, farmers, drone operators, and many others.

Want more insights? Listen to the full podcast episode here.

Want to unlock centimeter-level accuracy? Discover Emlid Reach receivers and see how they power precision mapping, surveying, and inspection.