- Russia can disable US-made Ukrainian missiles because some use GPS signals.
- Both sides are waging a battle to jam the electronics of missiles and other weapons.
Russia is disabling "sophisticated" missiles that Ukraine's Western allies provided by scrambling their GPS coordinates, according to reports.
Bryan Clark, a senior fellow at Hudson Institute, a US think tank, told BBC News that Russia's electronic-warfare capability had significantly improved during the conflict with Ukraine.
He said that Russia was now deploying hundreds of small, mobile electronic-warfare units along the front line, having previously relied on large, cumbersome units that could be easily targeted.
Clark told the BBC that Russian technologies were able to jam missiles' GPS coordinates, disable Ukrainian drones, and suppress Russian radar signals that were used by Ukraine to identify targets to attack.
One such system, the R-330Zh Zhitel, is able to suppress satellite signals.
"Zhitel can jam a GPS signal within 30km of the jammer," Clark said. "For weapons like JDAM bombs, which use just a GPS receiver to guide it to the target, that's sufficient to lose its geolocation and go off target."
It's not the first time concerns have been raised about the effectiveness of Joint Direct Attack Munition, or JDAMs, in Ukraine, with the UK think tank The Royal United Services Institute in January citing leaked US documents in which officials expressed concern that Russia was jamming JDAM GPS coordinates.
JDAM bombs are among the weapons the US had provided Ukraine with and can be launched by air to hit targets up to 45 miles away. Like many long-range missiles, they rely on GPS coordinates to reach their targets.
They have a greater range than the HIMAR long-range missiles that Ukraine used to drive back Russian forces in a counteroffensive last year, The Defense Post reported.
They were also one of the weapons that Ukraine's Western allies hoped could help Ukraine in its new counteroffensive to drive back Russian invaders.
But Russian defenses have proven resilient against Western-supplied weapons, with Western tanks largely ineffective in the face of the huge minefields Russia has created to defend its positions in south and east Ukraine. Western offensive tactics have so far not secured Ukraine a decisive breakthrough.
The BBC reported that Ukraine is seeking to eliminate Russian electronic-warfare units before it launches missile strikes in a game of cat and mouse, or target them once they detect Russian attempts to block missile coordinates.