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What’s new: A claim in Al Jazeera that Iran is using an “unjammable” version of Bei Dou to guide its missiles and drones.

Why it’s important: The claim is being repeated by other news outlets, but it is wrong.

What else to know: Most of our readers know the claim is wrong already. But we checked with some RNT Foundation Advisory Council members just to be sure. Responses were in line with Prof. Todd Humphreys’ reply below. The text in quotes and italics is from the Al Jazeera article and Prof. Humphreys’ responses follow in bold:

“While the US can jam or deny access to the US government-owned Global Positioning System (GPS), which Iran’s military previously relied on, it cannot do much to interfere with China’s BeiDou system if that is what Iran is using.”

Not so.  There is much the US can do to interfere with BeiDou.  I am of course not privy to the particulars of the BeiDou military signals, but our side surely is.  And frequency hopping isn’t a more effective anti-jamming method than simply spreading the signal wider using spread-spectrum techniques unless the hopping pattern is responsive to the actual signal environment, which is unlikely (though not impossible) for BDS.

“Crucially, China’s system uses far more satellites than other navigational systems. According to data gathered by Al Jazeera’s AJ Labs data team, while the US GPS system has 24 satellites providing it with data, the Chinese system relies on 45. The two other main global navigation systems are Russia’s GLONASS and the European Union’s Galileo system, each of which have 24 satellites.”

The US system has 31 operational SV.  Yes, BDS has more when counting MEO, GEO, and IGEO SVs.  But quantity of SVs isn’t much of a protection against jamming.  In fact, a large number of SVs tends to reduce received SNR through multi-access interference.

I would not be surprised if Iran’s drones and missiles use BDS.  It would be more surprising if they got access to the military codes of BDS.

“They successfully deflected Iranian drones and missiles – which were using GPS signals to navigate – in 2025. Jamming techniques include tricking incoming drones with false coordinates. The BeiDou system can filter out such interference.”

I doubt BeiDou has some magical remedy to “filter out” spoofing.  They’re subject to the same physics and asymmetrical information the rest of us are.

“Military analyst Patricia Marins told the news outlet bne IntelliNews this week: “Unlike the civilian-grade GPS signals that were paralysed in 2025, BDS-3’s military-tier B3A signal is essentially unjammable.”

I’d like to have a conversation with Military Analyst Patricia Marins.  

Editor’s note: Article leads by reporting Iran is using Bei Dou instead of GPS. That is old news and no surprise. GPS is controlled by the U.S. military after all. And any nation or individual user is free to  use Bei Dou.

However, there are a lot of things in the article that are clearly incorrect. Check it out for yourself.  Here is the link to the full article on the Al Jazeera site.

Could Iran be using China’s highly accurate BeiDou navigation system?

Intelligence experts have suggested China has made its satellite navigation system available to Iran