Business Insider: A new US-Swedish bomb (GLSDB) may have already been pulled from Ukraine because it’s useless against Russian jamming
“Ukrainian and Western officials told The Wall Street Journal that the Ground-Launched Small Diameter Bomb (GLSDB), manufactured by Boeing and Swedish company Saab, had failed and was no longer in use pending an overhaul...
...As previously reported by Business Insider’s Mia Jankowicz, Ukraine received the bombs in early February after months of requesting long-range munitions in the hope of hitting targets in areas like Crimea.
In April, Defense One reported that Bill LaPlante, the Pentagon’s acquisition chief, had said a ground-launched version of an air-to-ground weapon had become vulnerable to Russian electronic warfare. The publication said he was likely referring to the GLSDB...
...A month later, three sources familiar with the matter told Reuters that the bombs’ guidance systems were running into Russian jamming, causing many of the launches to miss their targets...
...The weapons are GPS-guided, meaning that Russia has been able to remotely scramble their signals using its sophisticated electronic warfare capability, according to The Journal.
It’s one of a number of precision-guided US weapons that Russia has been able to neutralize or reduce the effectiveness of using electronic warfare in Ukraine.
Russian electronic warfare units have blunted the effectiveness of HIMARS-fired Guided Multiple Launch Rocket Systems and air-launched Joint Direct Attack Munitions.”
Interesting that the SDB seems more jam resistant when air launched. I'm guessing the IMU is confused by the launch ground launch sequence, and with jamming can't get reliable position updates to recover. Either a new M-code GPS receiver or some other update to the system might be able to increase jamming resistance. Or use Home on GPS Jam seeker (HOG-J) for the first salvo.