GPS Precision—Without GPS

The US Army Is Developing Artillery That Has GPS Precision—Without GPS

The artillery rounds are designed to operate in GPS-denied environments.

By Kyle Mizokami

 BRITISH ARMY PHOTO BY WARRANT OFFICER CLASS 2 TOM ROBINSON

The U.S. Army’s artillery is set to receive a new round of upgrades that will allow artillerymen to conduct precision fire missions without the use of GPS. The Army working to head off the day when enemies could jam the worldwide satellite-based navigation network, degrading the service’s ability to operate on modern battlefields.


Back in the 1980s, few if any understood the impact the upcoming Global Positioning System would have on the U.S. military. Originally designed to give U.S. forces the ability to orient themselves on and navigate across far-flung battlefields, GPS and the miniaturization of electronics quickly led to GPS-guided weapons. From bombs to artillery shells, GPS allows for a single munition to do the work of multiple munitions.

The U.S. Army currently fields three major GPS-guided artillery weapons and guidance systems: the M982 Excalibur 155-millimeter round, the XM1156 Precision Guided Kit GPS add-on that screws onto existing “dumb” 155-millimeter artillery rounds, and the 227-millimeter GMLR guided rocket.

The U.S. military’s reliance on the GPS network makes that network an attractive target. GPS satellites could be destroyed in orbit or disabled by potential enemies with access to space. Back on Earth, the GPS signal can be blocked or spoofed, forcing false location readings on GPS devices. Successfully doing so would deprive U.S. forces of one of their greatest advantages. North Korea occasionally jams South Korea, and recently an incident in the Black Sea pointed to Russian GPS spoofing.

Now, the U.S. Army is planning for GPS-denied environments with the new Precision Guidance Kit - Modernization. An enhancement of the original PGK kit, PGK-M will give U.S. forces the ability to continue launching precision strikes even if GPS is denied by the enemy.

It’s not exactly clear what the alternative to GPS is. Warrior Maven suggests it’s a collection of “ad hoc software programmable radio networks, various kinds of wave-relay connectivity technologies and navigational technology.” Radio networks that triangulate user positions in essence replacing satellites with ground transmitters are one possibility. Unfortunately, unlike satellites that look down from Earth orbit, ground transmitters have relatively short ranges and can also be jammed.

All of this drives home the fact that there is no single magic solution to navigation and targeting issues. While the US military will enjoy the benefits of GPS into the foreseeable future, it must also plan for times when it may have need a Plan B, and even go back to a compass and a paper map to get the job done.

Source: Warrior Maven