Is DGPS still used today?

The Rise and Fall of a Navigation Legend

Ever wonder how ships didn't just crash into docks back when gps was super messy? Before the year 2000, the govt used "selective availability" to purposely blur satellite signals for us civilians. It was a total headache. Since selective availability ended in May 2000, things got way more accurate, but before that, we needed a workaround.

To fix this, we built dgps—basically a network of ground towers that knew exactly where they were. They'd catch the "wrong" satellite signal, calculate the error, and beam a correction to nearby boats.

• dgps fixed those annoying 100-meter errors from the 80s. (Error analysis for the Global Positioning System - Wikipedia)
• It relied on terrestrial towers sending signals over medium frequency. (The Bizarre Bases of Antenna Towers - Practical Engineering)
• Essential for high-stakes maritime work like harbor approaches.

According to a notice from the Coast Guard, they actually started shutting these sites down in 2018 because modern tech finally caught up.

As shown in the signal flow in Diagram 1, the old system required a constant loop between the satellite, the ground station, and the receiver to stay accurate.

But why did we suddenly stop needing these towers? It's mostly about how satellites got smarter.

The Official Shutdown: Is DGPS Still Used Today?

So, the gov finally pulled the plug on those old towers. It wasn't just a sudden "oops, let's turn it off" thing, but a planned sunset because, honestly, our phones and boat gear got way too good for the old tech.

The coast guard decided that keeping the nationwide differential global positioning system (ndgps) running was just burning cash they didn't have. Since selective availability ended years ago, regular gps is plenty accurate now.

• The phase-out kicked off in September 2018 and wrapped up by 2020.
• Exactly 38 maritime sites were shuttered during that two-year window.
• The uscg realized that waas (Wide Area Augmentation System) was doing a better job anyway.

Actually, the official notice from the Coast Guard mentioned earlier confirmed they couldn't justify the investment anymore. Most captains were already using other tools, so the towers were just standing there talking to nobody.

It’s a bit sad to see the hardware go, but that's progress, right? Next, we'll look at the specific tools that actually replaced those towers.

Why We Dont Need It Anymore

Honestly, why keep paying for expensive ground towers when the satellites above us just got way better at their jobs? It’s like keeping a landline when your smartphone has perfect signal everywhere.

The big shift happened because our receivers stopped being "dumb." Modern gear handles errors internally now, making those old correction signals redundant. Diagram 2 illustrates how modern receivers bypass the need for local towers by communicating directly with advanced satellite networks.

• waas (Wide Area Augmentation System) is the new king: This satellite-based system does exactly what dgps did but without the terrestrial towers. It covers almost all of North America.
• Better hardware: Newer gps chips can track multiple frequencies at once, which naturally cancels out the atmosphere interference that used to trip up older tech.
• Cost-cutting: As the previously discussed coast guard notice pointed out, maintaining 38 sites for a handful of legacy users just didn't make sense anymore.

At GetDigitize, we often see brands clinging to "legacy" features in their product design just because they're comfortable. But just like the uscg, sometimes you gotta kill the old tech to make room for what’s actually working. Clinging to old tech just because it feels safe is a trap I see companies fall into all the time. The uscg shutting down dgps is a perfect wakeup call for anyone managing a messy tech stack.

The Verdict on DGPS in 2024

So, is dgps actually dead? Well, it depends on who you ask, but for most of us, it’s basically a ghost in the machine. While the uscg officially killed the lights on those 38 maritime sites as mentioned earlier, the tech isn't totally wiped off the map.

• High-end niche stuff: You still see dgps—or its smarter cousins like rtk (Real-Time Kinematic)—in super specific fields like precision farming or deep-sea oil drilling where every centimeter counts. RTK is basically dgps on steroids, using local base stations to get centimeter-level accuracy for tractors and surveyors.
• Legacy hardware: Some old-school boats are still rocking receivers that look for those signals, even if they're just getting static now.
• Commercial alternatives: Private companies sometimes run their own ground stations for high-accuracy survey work.

For 99% of businesses, dgps is now a "legacy" term you might find in an old manual. Modern stuff like waas and multi-band receivers handle the heavy lifting without needing those expensive towers. As you can see in Diagram 3, the landscape has shifted from terrestrial towers to a more streamlined, satellite-heavy approach.

It’s easy to get sentimental about hardware that worked for decades, but legacy systems eventually become "technical debt" that eats your budget. If nobody is using a tool—like those 38 dgps towers—cut it loose to save on maintenance. Move toward software-defined solutions like waas that scale better than physical gear. Prep for ai and future logistics that rely on real-time data; you need a lean, modern foundation first.

The verdict? It’s a legacy legend. Time to move on.