When GPS Can’t Be Trusted: Why Protecting Satellite Signals Matters to Surveying and Engineering

Most of us think of GPS as the little blue dot on a phone screen.

For surveyors and engineers, it is much more than that.

Global Navigation Satellite Systems (GNSS)—including the U.S. GPS system—have become an important part of the technology used to establish positions, collect field data, map infrastructure, support construction, and perform surveys with remarkable efficiency and precision.

That is why a recent BBC Future article examining the growing fight to protect the world's satellite signals caught our attention.

An Invisible System We Depend On

Satellite navigation signals support far more than driving directions. Aviation, shipping, telecommunications, emergency response, financial systems, utilities, agriculture, construction, surveying, and other industries rely on accurate positioning and timing information every day.

But those signals have a vulnerability: by the time a satellite signal travels thousands of miles and reaches a receiver on Earth, it is relatively weak.

That makes interference a significant concern.

Two of the threats receiving increasing attention are jamming and spoofing.

Jamming occurs when another radio signal overwhelms the legitimate satellite signal, preventing a receiver from determining its position.

Spoofing can be even more problematic. Instead of simply blocking the signal, a false signal can imitate a legitimate satellite transmission and cause equipment to calculate an incorrect position or time.

For industries that depend on reliable location data, the distinction is important.

Sometimes the risk isn't that your equipment tells you it doesn't know where it is.

It's that the equipment confidently tells you the wrong answer.

What Does This Mean for Surveying?

Modern surveying has benefited tremendously from GNSS technology. Survey-grade receivers, real-time correction networks, base-and-rover systems, and other technologies allow survey crews to efficiently collect accurate positional information across large project areas.

But professional surveying has never been as simple as placing a receiver on a point and accepting whatever coordinates appear on the screen.

Surveyors evaluate the quality of their observations, equipment performance, satellite geometry, correction data, environmental conditions, existing control, field evidence, and other information before relying upon a position.

Redundancy and verification matter.

A satellite-derived coordinate is one piece of evidence—not a substitute for professional judgment.

That becomes increasingly important as the systems supporting modern positioning face new sources of interference.

Old-School Surveying Still Has a Place in a High-Tech World

The discussion surrounding satellite interference is also a good reminder of why surveying continues to use multiple measurement technologies.

GNSS is an extraordinary tool, but it is not the only tool available to a surveyor.

Depending on the project and site conditions, a survey may incorporate robotic total stations, conventional observations, leveling, terrestrial measurements, aerial data, existing monuments and control points, or other methods to independently confirm results.

Technology has transformed surveying, but good survey practice has always included an important principle:

Check your work.

As positioning technology becomes more sophisticated, that principle becomes more important—not less.

The Bigger Infrastructure Question

The BBC article raises an issue that extends well beyond the surveying profession.

Our infrastructure is becoming increasingly dependent upon systems most people never see.

Satellites, communications networks, positioning systems, digital mapping, remote sensing, and interconnected data platforms allow engineers and surveyors to work faster and provide information that would have been difficult to obtain only a generation ago.

But technological efficiency also creates technological dependence.

Building resilient infrastructure therefore means thinking not only about roads, bridges, utilities, airports, and buildings themselves, but also about the digital and positioning systems used to design, construct, operate, and maintain them.

Protecting GNSS reliability—and developing effective alternatives and backup methods when satellite positioning is unavailable—will likely become an increasingly important part of that conversation.

Technology Changes. Fundamentals Don't.

Surveying has changed dramatically from chains and transits to electronic total stations, satellites, drones, scanners, and sophisticated mapping platforms.

What has not changed is the responsibility to produce reliable information.

New technology gives us remarkable capabilities, but accuracy still depends upon knowing how that technology works, recognizing its limitations, independently checking results, and applying professional judgment.

The worldwide effort to protect satellite navigation signals may seem far removed from a property corner or an engineering project in Kentucky.

It isn't.

Those faint signals traveling from space are now part of the infrastructure behind the infrastructure—and protecting their reliability matters to all of us.

Abbie Jones Consulting, PSC provides professional surveying and engineering services throughout Kentucky and the surrounding region. Our team combines modern technology with experienced professionals and established surveying and engineering practices to provide reliable information for every project.