M1156 (PGK) GPS-guided fuze

M1156 is the American Precision Guidance Kit (PGK), a high-explosive (HE) fuze designed to convert standard unguided 155 mm projectiles into guided munitions.

It is a combined fuze and Global Positioning System (GPS) guidance module used to improve the ballistic accuracy of the current inventory of 155 mm field artillery projectiles. In-flight guidance is achieved by means of canards that control the airflow around the projectile. In flight, the PGK uses GPS position information to adjust the control surfaces and the projectile's flight path toward the aim point.

The operational effectiveness of the PGK is effective against targets engaged by field artillery units. PGK fuzes have demonstrated sufficient accuracy and reliability to allow gun artillery units to deliver satisfactory accuracy (less than 50 meters) when firing existing unguided 155 mm high-explosive projectiles at medium and long ranges.

In test firings with M795 HE and M549A1 HE Rocket-Assisted Projectile (RAP) the fuze showed an average accuracy of 13 m.