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This is an interesting article. It has a very strong AI accent.

I really wish I could tell how real it is. When some part of it I can tell is AI slop, how much of it is AI slop? Inside GNSS has always been a marketing rag with sometimes some interesting articles.

The author is a security researcher, so maybe poking at GPS bits makes sense, but talking about floating point bit depth? There's too much slop for me to figure out if there's anything of real interest or if this is just a hallucination.

Edit. After reading more carefully this is 100% AI slop. Inside GNSS published Steven Murdoch's chat gpt session. Maybe some data was transmitted? The only way you'll actually know is to redo the research your self. There are many fabrications / confabulations that clearly happen with AI in the text.

Paradoxically, in the blog post he speaks with his own voice, describing the evidence better amassed in ... the AI written article.
"Numbers station" is a weird analogy, because the idea of a numbers station was to broadcast messages to undercover operatives in a way that can be received using unmodified (and therefore non-suspicious) household radio receivers.

Here, it appears to be a rekeying system for specialized military gear.

So, a number station sending a message 'detonate the bomb' isn't a number station, because most people don't have the bomb?
GPS was always a dual use system. This is very detailed and specific, but not interesting or surprising. Research has been study GPS signal data, found parts that are encrypted and he doesn’t understand. The end. Article seems only intended to generate an emotional response of “how dare they use GPS for war, man!”
Meanwhile Starlink and Starshield: Hold my beer ;-)
Clickbait from 404 Media? Surely not!

The part they kept out of the headline:

> for use in distributing the keys for accessing the military GPS signals

It’s common knowledge that the military has access to a separate, encrypted, higher-precision GPS signal. “Numbers station” implies that they’re distributing unrelated encrypted information, but they’re not; it’s not surprising that GPS signals would be used to deliver information related to GPS, even if only military receivers have any use for it!

People are complaining about a clickbaity title but it's a fascinating article I am not sure most would read otherwise

What's interesting to me is how out of date US GPS system is compared to China's BeiDou

and while most US GPS receivers will use Russia's GLONOSS, China's BeiDou is blocked

https://news.ycombinator.com/item?id=47849174

The story links to the current issue of the Inside GNSS magazine but the article isn't available in the digital edition, apparently. It's in the print edition, readable at https://lsc-pagepro.mydigitalpublication.com/publication/?i=...

The source data and analytical code (in Julia) is also available at https://lsc-pagepro.mydigitalpublication.com/publication/?i=...

In my view people nitpicking the 404 media story are being ridiculous. Everyone in their audience knows GPS originated as a military system, indeed I think most of teh general public knows that. Bashing them for not mentioning this is just looking for something to be mad about.

I know it isn't really a number station but I wanted it to be true...

Someone broadcasting one time pad messages using GPS over years...

a spy operative using jogging app changing routes slightly

or maybe a cartel member embedded inside highly hostile countries like Singapore

An interesting lesser known role of GPS is that it is part of the US nuclear monitoring network and it's L3 signal is part of this.

https://www.youtube.com/watch?v=DjLnIb41DuQ I Found The US Nuclear Detection System In Space (saveitforparts)

Messages would be split over multiple mediums or be slow.
> To make processing this massive dataset practical, we built a Julia pipeline to extract the bits directly into a DuckDB database.

The raw data is a bit more than 1GB per annum.

The data of interest is 176 bits every 12.5 minutes for 19 years. That is, about 17MB of data. Possibly multiplied by the number of satellites, roughly thirty.

It's not big data.

Though I take your point that it’s not big data by the conventional use (i.e. requiring a distributed computing to process). The phrasing in the original article was better: “To make iterative analysis practical, we wrote a Julia pipeline: NetCDF source files are converted to Apache Arrow, then thread-parallel bit extraction is performed into a DuckDB database.”