The accuracy and prerequisites of using GPS receivers are changing. If you currently use, or plan to use, GPS receivers in your systems, then it is important to be aware of these 4 GPS trends:

Trend 1. There are plenty of satellites overhead.
Key Term: Multi-Constellation

There is a growing number of global navigation satellite systems (GNSS) online and many commercial receivers will default to using any or all of the available constellations: GPS (United States), GLONASS (Russia), Galileo (European Union), and BeiDou (China). Multi-Constellation capability means that a receiver can use the many satellites operated by multiple countries or entities.

Trend 2. New civilian signals are coming online, adding to the accuracy and robustness of the computed position, velocity, and time.
Key Term: Multi-Band or Multi-Frequency

New civilian signals are being fielded. These additional signals, usually broadcast on new frequencies, are being adopted by receivers and thus touted using terms like multi-band, multi-frequency, dual frequency, or triple-band receivers. In the case of GPS, the three new civilian signals are L2C, L5, and L1C (not to be confused with the legacy civil signal called L1 C/A). Measurements from these additional frequencies enable correcting for certain atmospheric errors (e.g. ionosphere effects) and mitigating the impact of multipath and signal interference. These provide modest improvements in accuracy. The real improvements, however, come from the next trend.

Trend 3. Low-cost receivers with an data connection will be capable of cm-level positioning accuracy. It can be 100x better than what we are used to.
Key Term: GNSS Correction Services

Standard GPS is accurate to within several meters ( > accuracy). Correction services can transform meter-level accuracy into an astonishing cm-level positioning accuracy. This level of accuracy was previously only attainable by high-end users with expensive equipment. It required setting up a second GNSS receiver nearby to act as a base station. Those measurements were then fed to the moving receiver (i.e. rover) which computed and applied corrections to its own solution. A growing number of correction services manage a network of base stations regionally or globally. That means a GNSS user with an data connection, and an active subscription, can access the corrections without worrying about a local base station. This, together with the multi-band and multi-constellation trends means cm-level accuracy can be attained with low-cost receivers.

Trend 4. Disruptions to GNSS, both intermittent and long-term, are real and will be the norm for the foreseeable future.
Key Terms: GNSS Interference, Jamming, and Spoofing

With all these technical advances for GNSS, there is also unfortunate headwinds. GPS was born for military utility, and something similar can be said of other GNSS constellations. In the early years, the motto organizing the GPS development efforts made this intention clear: "drop 5 bombs in the same hole". More so than ever before, civilian users of GNSS are vulnerable to regional and political events attempting to control access to GNSS. The trend is illustrated by the April 30, 2024 WIRED article titled The Dangerous Rise of GPS Attacks.

Four Actions for Technical Teams

If your system can or does use GNSS, then the following should be done:

Action 1. Check your hardware for multi-constellation and multi-band support.

It may require changing a firmware setting or upgrades to software or hardware, but the performance benefits are immediate and will only improve as new civilian signals come online.

Action 2. Answer this: What changes if position accuracy is 100x better?

Attaining cm-level positioning accuracy outdoors, at reasonable cost, is becoming real. This may not have been the case during the original system design. So it is worth revisiting past assumptions and considering what may be possible with this added sensing precision.

Action 3. Develop a plan for correction services.

Connectivity and corrections services go hand-in-hand. If a system does or will have connectivity, then it is time to also develop a plan for exploring GNSS correction services.

Action 4. Answer this: What happens if GNSS is unavailable?

This is an exceedingly hard question to answer. GNSS is involved in so many aspects of modern infrastructure that it is difficult to know what will be impacted by a GNSS disruption. Nonetheless, it is time to think this through and decide what level of GNSS dependence is acceptable for your system.

Adoption of GNSS is both growing and changing. We'll continue to watch these trends and would love to receive your questions or comments.

Photo by Scott Blake.