Global Positioning Satellite (GPS) navigation and guidance is providing effective, low cost means for precision targeting. This targeting option is used primarily against fixed or relocateable targets, where the location of the target is expected to remain fixed for the duration of planning and execution of the attack. GPS guided weapons are provided with an integral multi-channel GPS receiver and Inertial Measurement Unit (IMU) which monitors the weapon’s locations and attitude to adjust its flight path to accurately impact on the target. In low cost un-powered weapons, the guidance system adjusts the weapon’s free fall to hit a pre-selected point fed into the weapon prior to takeoff. GPS is also used in guided missiles and cruise missiles, for mid-course navigation.
GPS weapons are not designed for engagement of moving targets. GPS guidance provides very efficient means for coordinated attack, as they are unaffected by weather, target concealment or countermeasures. Modern weapons are more immune to GPS jamming, by the use of advanced GPS-AJ modules. Basic GPS weapons have limited precision (around 1-10 meter CEP) but can also provide higher precision by using combined GPS/SAL or GPS/IIR techniques which also provide aimpoint selection. GPS guided weapons can be preloaded with target coordinates before the flight, or link with the aircraft weapon’s control systems, over the 1760 armament control bus, to receive updated target coordinates directly from on-board or remote targeting systems. Modern SAR and target pods are already supporting geo-targeting capabilities, and automatically extract target coordinates from the images they generate.