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Britain’s Royal United Services Institute and the US’s Pentagon have acknowledged that Russian electronic warfare is reducing the accuracy of American guided weapons, including JDAMs and HIMARS rockets:

In particular, Withington pointed to the Russian Army’s R-330Zh Zhitel, a mobile truck-mounted jamming system specifically designed to disrupt GPS and satellite communications in the 100 MHz to 2 GHz wavebands. “Signals from the U.S. GPS satellites which JDAM kits use are transmitted on wavebands from 1.164 GHz to 1.575 GHz,” according to Worthington. “These fall squarely within the R-330Zh’s catchment area.”

Worthington claims to have seen official documents that put the R-330Zh range at 18.6 miles, with a 10kW-strong jamming signal. This is “notably stronger than the strength of the GPS signal arriving from space,” he noted. “Moreover, the closer the GPS receiver is to the R-330Zh’s jamming antenna, the stronger the jamming signal becomes.”

In theory, the Selective Availability Anti-Spoofing Module upgrade to JDAM in the early 2000s should ensure that JDAM will only respond to authorized M-Code encrypted military GPS signals. However, Russian jammers may still be able to disrupt the signals through “sheer brute force” jamming beams, Withington said.

Russia could also intercept M-Code signals and retransmit them with slight alterations to a JDAM, causing the bomb to miss. Efforts to bypassing Russian interference by using signals from multiple GPS satellites could in turn be countered by employing multiple jammers.

Russia’s counter-GPS efforts are part of a massive electronic-warfare campaign that has also disrupted Ukrainian radio communications and drone operations.

Russian forces “now employ approximately one major EW system per 10 kilometers [6.2 miles] of frontage, usually situated approximately 7 kilometers [4.3 miles] from the frontline,” according a recent RUSI report on Russian tactics. This jamming has contributed to a Ukrainian drone loss rate that RUSI estimates to be as high as 10,000 UAVs per month.

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Nonetheless, Russian electronic warfare has limitations. Emitting jamming beams discloses a jammer’s location, and Ukraine appears to have located and destroyed Russian systems such as the R-330Zh. Ironically, smothering the airwaves with powerful jamming beams may also be disrupting Russian GPS and radio communications.

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