Russian interference is reported to seriously reduce the effectiveness of GPS-guided munitions supplied by the West. As a result, the US Air Force is purchasing additional homing heads (homing) to give the high-precision extended-range direct hit bombs (JDAM-ER) supplied to Ukraine the ability to hit GPS signal jammers. It is believed that this will turn one of the weapons most affected by this countermeasure into a means used to destroy it.
On May 3, 2024, the US Department of Defense announced the conclusion of a $23.5 million contract with Scientific Applications and Research Associates Inc. (SARA) for the "acquisition of GPS jamming devices" and their integration into existing wing kits for direct-hit aviation ammunition. The contract also involves foreign military sales to Ukraine.
JDAM-ER cruise bombs have been used by the Armed Forces of Ukraine since at least March 2023. For their use, Soviet MiG-29 and Su-27 fighters of the AFU Air Force are also involved. The ammunition is secured using specialized pylons and controlled by a tablet system in the hands of their pilots. Detailed information about the homing system itself is limited, but SARA has been developing similar capabilities for integration into various precision-guided munitions for many years.
JDAM-ER under the wing of the Ukrainian MiG-29. A specialized pylon is visible, used for the use of these weapons from these aircraft, as well as the Su-27
According to the developer, if the enemy tries to complicate the battlefield with scattered or competing radio frequency energy, the HOJ subsystem (home-on-GPS, or "home to GPS jammer") from SARA allows the main guided bomb or missile to hit the source of such energy at the request of the operator. The HOJ subsystem is compact and 10 times cheaper than the previous generation equipment. HOJ uses solid-state components and a common interface for ammunition, which provides fast and inexpensive integration.
The JDAM flatbed bomb control system in the cockpit of the AFU fighter
In the future, it is planned to include GPS jamming in other precision-guided munitions supplied by the West for the Armed Forces, including high-speed anti-radiation missiles AGM-88 (HARM). HARM-movs already have a "home to GPS jammer" function, but it is unclear whether Ukrainian combat aircraft will be able to use them in this mode. In any case, it is believed that providing Ukraine with JDAM devices capable of hitting Russian GPS jammers not only makes sense, but may also become an increasingly important opportunity.
According to the analytical center The Royal United Services Institute (RUSI, Great Britain), when high-precision 155-mm Excalibur artillery shells with a GPS guidance system were first used in Ukraine, the effectiveness of hitting targets was 70%. Six weeks later, thanks to the adaptation of Russian electronic warfare, it dropped to only 6%. Earlier, there were reports that JDAM-ER cruise bombs and 227 mm guided MLRS (GMLRS) shells were negatively affected by Russian GPS jammers.
According to Western experts, Russia's use of GPS signal jamming extends far beyond Ukraine. Thus, Russia's use of such systems in the Baltic region, probably to protect critical facilities from attacks by Ukrainian long-range UAVs, has become so noticeable that it is now having a serious and potentially dangerous impact on commercial aviation.
Considering all this, arming the Armed Forces of Ukraine with ammunition capable of targeting Russian GPS jammers is considered very valuable. It could help eliminate, or at least mitigate, the impact of Russian electronic warfare interference. While the direct destruction of emitters will certainly help other guided weapons reach their targets, the simple threat of being destroyed by a combat weapon as a result of radiation should make it difficult to use jammers. At the very least, this can lead to them being activated for shorter periods of time.
The current plan to send JDAM-ER equipped with GPS with the "home to GPS jammer" function to Ukraine also raises the question of what capabilities the US Armed Forces themselves have in this regard. This is doubly important, since reports of a decrease in the Russian electronic warfare capabilities of precision-guided munitions supplied by the United States indicate alarming vulnerabilities in such weapons used by both the US army and various allies and partners.
In general, the contract for the supply of new home-on-GPS for JDAM-ER cruise bombs for the Armed Forces of Ukraine emphasizes that Russian electronic warfare systems are a very real problem. It also indicates that work is currently underway to mitigate this problem, which may have consequences far beyond the scope of this particular conflict.
Based on the materials of the resource twz.com