GPS in the Port of Baltimore

By Taleya Younger

Edited by Ashley Fogarty

GPS Satellite (GPS.gov)

GPS technology is one of the most important tools in modern maritime operations. It provides accurate location data that helps ships, trucks, and port equipment navigate safely and efficiently. In the Port of Baltimore, GPS assists with vessel tracking, terminal logistics, and safety coordination, allowing one of the nation’s busiest ports to function smoothly.

How GPS Aids Navigation (US FAA)

What is GPS and How Does it Work?

Most people think of GPS as something inside their phone or car. In reality, it is powered by a worldwide satellite network known as the Global Positioning System (GPS). It uses a constellation of satellites that continuously broadcast their location and precise time from atomic clocks. Receivers on ships, vehicles, or devices calculate their position by measuring the time it takes signals to reach them from at least four satellites. GPS enables ships and port vehicles to know their position to within a few meters at all times. GPS accuracy, however, depends on your receiver being able to “see” several satellites simultaneously. The problem is that GPS signals do not always travel in a straight line from the satellite to your device. Along the way, they can pass through buildings, trees, and other objects that weaken or slightly redirect the signal. Each small change may not matter on its own, but together they can reduce accuracy. This effect is called multipath interference. In addition, GPS signals must pass through several layers of Earth’s atmosphere before reaching your receiver. As they pass through the upper atmosphere, the signals can slow down slightly. This effect is called ionospheric delay.

GPS Aid To Navigation (ATON) (GPS.gov)

GPS in Port Operations

In the Port of Baltimore, GPS is integrated into a variety of systems that support safe and efficient operations. It helps coordinate the movement of ships, cranes, trucks, and other heavy machinery, while also tracking shipments in real time. After the Francis Scott Key Bridge collapsed in March 2024, GPS played a vital role in debris management and vessel routing as sections of the harbor reopened. By relying on GPS location data, response teams were able to navigate safely and efficiently through restricted areas.

GPS Synchronized Power Grid (US NIST)

Vulnerabilities and Challenges

Despite its advantages, GPS is not immune to disruption. Signal interference, jamming, or spoofing can cause temporary outages or errors in positioning data. Because of this, ports have historically relied on backup systems such as radar and the now largely retired Long-Range Navigation (LORAN) system. The U.S. government continues to explore ways to strengthen GPS resilience through enhanced signals and alternative timing networks.

National Positioning, Navigation, Timing System Infrastructure Enabled By GPS (US DOT)

A Port Without GPS

If GPS service were lost, port operations would face major delays. Ships would rely more heavily on radar and manual navigation, while trucking and crane operations would revert to slower, line-of-sight coordination. Although such a loss would not cause chaos, it would lead to reduced efficiency and higher operating costs. The Port of Baltimore, like other modern ports, depends on GPS to maintain precise scheduling, safety, and communication across all levels of its intermodal network.

GPS technology has transformed how the Port of Baltimore operates. From ship tracking and cargo handling to emergency response, it supports nearly every aspect of the port’s logistics and safety systems. While vulnerabilities exist, continued investment in GPS and related infrastructure helps ensure that Baltimore’s maritime network remains efficient, resilient, and forward-looking.