Northrop Grumman unveils anti-jam version of its artillery guidance kit

Northrop Grumman will build a new version of its GPS-guided artillery kit with added anti-jamming technology, the company announced September 9, aimed at keeping artillery accurate even when an enemy is jamming GPS signals.

The new kit, called the PGK E5, is the latest version of the M1156 Precision Guidance Kit, a fuze-sized device the Army has used since 2015 to turn standard 155 mm artillery shells into GPS-guided weapons. Rather than requiring a specialized, more expensive shell, the PGK screws into the fuze well of an existing 155 mm high-explosive round, correcting its flight path using GPS signals. The base version has an accuracy of better than 30 meters (98 feet) circular error probable, a significant improvement over unguided artillery.

Northrop Grumman said the E5 variant keeps the same form factor and training requirements as earlier versions, so soldiers using it in the field see no difference in how the kit is loaded or fired. The company said recent testing in GPS-degraded conditions showed the E5 exceeding both the minimum and target accuracy requirements set for the program, and that better precision means fewer rounds are needed per engagement, which the company says also reduces collateral damage.

Electronic warfare has become a bigger factor in artillery fights in recent years, particularly in Ukraine, where both sides have used GPS jamming to degrade the accuracy of guided weapons. The PGK E5 is built to counter that kind of interference directly, rather than relying on GPS signals that can be blocked or spoofed near the front line.

The M1156 program has grown steadily since it entered service, with the Army placing dozens of incremental production orders with Northrop Grumman over the past decade, ranging from single-digit millions to tens of millions of dollars at a time. On September 4, five days before the E5 announcement, the Army awarded Northrop Grumman a separate indefinite-delivery, indefinite-quantity contract worth close to $863 million to manufacture, inspect, test, package and deliver M1156 kits and their variants through September 2031. PGK-equipped rounds are compatible with artillery systems including the Army’s M109A6/A7 Paladin self-propelled howitzer and the M777A2 towed howitzer.

The kit is used by the U.S. Army and Marine Corps as well as allied forces including Australia, Canada and Finland. More than 100,000 PGK units have been built since production began in 2013.