Shutdown of Starlink location feature won’t dampen interest in GPS alternatives.
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Starlink blocks access to its GPS alternative ahead of SpaceX IPO
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Amazing that you can get 2 meter accuracy without atomic clocks! I had long heard about the importance of precision timekeeping to fight relativistic effects that would otherwise prevent global positioning from being very accurate... was that just a folk assumption since that's how GPS does it?
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Am I reading this correctly, is Kassas et al using homebrew equipment to generate a positioning signal using any satellites?
Apologies if I misread. If not, good on ya! Reminds me of the hardware hackers in William Gibson's universes.
Apologies if I misread. If not, good on ya! Reminds me of the hardware hackers in William Gibson's universes.
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I'm no expert but I would assume the shear number of satellites the researchers are calculating against does a lot to smooth out the clock skew of individual sat's timestamps.
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There's a whole field of people using existing signals for other uses. It covers a pretty broad range, a small selection of which includes: harvesting power from radio broadcasting, television broadcasts for stealth aircraft detection, GPS reflections for water height sensing, 802.11 frames for locating people inside buildings, and satellite communications here for navigation. The signals are already there; it just needs creative processing.
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Unauthenticated PNT implies that adversarial nations could use it for missile guidance. (Think Russia glide-bombing Kiev, or the reverse). They may be legally obligated to put a stop to that.
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Since there are no moving parts needed to switch the beam between satellites, would it be possible to do some kind of time-division multiplexing to talk to multiple satellites at once?
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I'm not sure where the 'legal obligation' would come from--certainly not Russia or Ukraine?
It seems like the profit motive is stronger: Why give it away for free when you can sell it to many different governments and commercial entities?
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It seems like that could be done (with custom software), but would interfere with network throughput (if that's important), and not as accurate as option B: coordinated connections of multiple dishes.
I'm sure SpaceX will sell all of these options to the US military (if they aren't using them already) for the low low price of... ONE TREEELION DOLLARS!!! (/musk maniacal laughter...)
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I'm sure the US government doesn't like unknown actors having access to "good enough for a cheap cruise or ballistic missile" guidance signals. The US Government can't tell Europe, Russia, or China to turn off their GNSS networks, but they can certainly lean on SpaceX.
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ITARS. SpaceX is an American company and has to follow American law.
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When I was in middle school, I remember researching GPS as a futuristic technology. At the time, we couldn't even imagine a pocket-sized computer that could provide point-to-point navigation across the country with real time traffic data.
That's because the best computer we had at the time was an Apple Performa, and our teacher was writing a grant request for thousands of dollars to double its RAM - to 8 MB.
That's because the best computer we had at the time was an Apple Performa, and our teacher was writing a grant request for thousands of dollars to double its RAM - to 8 MB.
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The software could probably be reconfigured to receives from multiple at once. Bidirectional communications would probably not be viable however; at least without risking their license. (There are specific restrictions on their antenna system. Phased arrays are subject to technology restrictions.)
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It would come from the U.S. where Starlink is based as a company, or from other nations where it wants to do business.
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As the author says, there are multiple reasons to pull the PNT feature. Undocumented features eventually become assumed features if they gain traction. When that happens, any change or break in the API will result in negative press. It's better to block it while the numbers are low. If you're going to support a feature forever, then you'll want to charge for the work, so you'll finalize the API and put it behind a paywall.
Even though it makes sense, I'm still sad about this. A lot of really neat hacker projects came out of exploiting the debug interface. My son was able to downlink images from the NOAA satellites (before they were DOGE'd) by grabbing a used DishNet Tailgater for $20, replacing the dish with a larger one made of 3D-printed parts and aluminum foil, and then hooking it up to open-source software to track the satellites.
Nonetheless, it's awesome to hear that alternate methods are proving to work. Making passive use of all those radio waves makes for some really awesome projects for young engineers. An SDRL is an excellent stocking stuffer.
Even though it makes sense, I'm still sad about this. A lot of really neat hacker projects came out of exploiting the debug interface. My son was able to downlink images from the NOAA satellites (before they were DOGE'd) by grabbing a used DishNet Tailgater for $20, replacing the dish with a larger one made of 3D-printed parts and aluminum foil, and then hooking it up to open-source software to track the satellites.
Nonetheless, it's awesome to hear that alternate methods are proving to work. Making passive use of all those radio waves makes for some really awesome projects for young engineers. An SDRL is an excellent stocking stuffer.
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Every privatization of essential infrastructure is a potential hostage situation. No Board not subject to public elections which meets in secret and can't be held accountable by the general public has any business controlling anything anyone really needs.
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They kind of do have atomic clocks, the satellites will themselves have GPS for positioning. GPS provides a very good time signal, it’s derived from the onboard atomic clock after all! It seems quite likely that starlink would be using that as a reference anyway as they already get it.
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There's atomic clocks and then there's relativistic correction. The two aren't quite the same thing. I'm sure relativistic correction is still needed, even with less accurate clocks, so long as we're talking about devices in orbit. Indeed, reading this made me MORE certain in it's need, rather than less, since now it looks like those corrections will need to be accounted for locally rather than on-satellite.
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So do you propose that all utilities, transport etc. should be no longer privatized and revert to public utilities?
You'd get rid of 'potential' hostage situation which can be easily resolved with government pressure or legal changes, and replace it with the usual governmental civil dept inefficiency and lack of accountability.
I agree that private monopoly is awful, and we're very close to that here since SpaceX is so far ahead of alternatives. But even so, if they really try to hold their customers hostage, they do have choices to migrate to in most cases. Whereas, if a public utility messes up there's no competitor at all.
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First, since when is Starlink essential infrastructure?
Second, why would a is company not put everything in the service of the country it belongs to?
Third, why does everyone assume the government won't just take away things if they have to? (Railroad, Telegraph during WW1, coal mines in WW2, Fannie Mae and Freddie Mac in 2008)
In the meantime the infrastructure isn't subjected to BS political games.
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There was a paper published in theJournal of Institute of Navigation recently that discusses using the doppler shift of the Starlink signal (a la TRANSIT gnss) to determine your position using passive listening.
https://doi.org/10.33012/navi.685
Unveiling Starlink for PNT
Journal of the Institute of Navigation
It doesn't have to be limited to Starlink. Any transmitting satellite can be a source using the published ephemeris and a SDR.
Edit:
Another paper that delves deeply into the topic, with UAVs:
UAV Navigation with Starlink
Ohio State University
https://doi.org/10.33012/navi.685
Unveiling Starlink for PNT
Journal of the Institute of Navigation
It doesn't have to be limited to Starlink. Any transmitting satellite can be a source using the published ephemeris and a SDR.
Edit:
Another paper that delves deeply into the topic, with UAVs:
UAV Navigation with Starlink
Ohio State University
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In the mid 90's, I told my girlfriend that someday people would be walking around with computers in their pocket. I considered it an obvious extrapolation from mainframe to mini to desktop. She didn't believe me. We already had mini desktops that would probably have fit in my cargo pants pocket, so it wasn't even a big stretch.
I am still waiting for a nice dock that I can drop my phone into, and use it instead of a laptop or desktop.
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I understand your concern, but when it's all in the control of the government, there's ALSO a risk for it's use to oppress people. Indeed, that's often one of the first tools of fascism and dictatorships. Don't get me wrong, I loathe the notion of privatizing space, but not because I think that ONLY the government should be in control of it, but rather because checks and balances won't really be available once corporations can settle themselves up and out of government's reach.
Rather, the solution to this seeming paradox is for the employees, all of them, to actually own the business and have a legally enforceable right to vote on leadership and decisions made in that company. If government controlling corporate resources doesn't work, and CEO controlled researches doesn't work, let's give employee controlled resources a try.
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And use the phone screen as a track pad! I'm surprised that doesn't seem to exist.
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You young whippersnappers have no appreciation for what it was like in the old days.
My freshman year of college, I got to play with an evaluation kit for the brand new Intel 8080. IIRC, it had sockets for two 256 byte proms (EEPROMs) and a socket for 128 bytes of memory.
It was a big deal that we could erase the EEPROMs under UV and reprogram them in less than a half hour.
1/2 /s
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Bah - when I was at college we had a big stack of punch cards formatted for FORTRAN
which I used as really nice bookmarks because I'm old but not that old 
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And when the time comes a company suffer monetary loss, who will squeal the first against reaching into their own wallet to cover it?
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The CEOs reach into their employee's wallets all the time. At least this would put it to a vote, and if it fails, it'll be their own decisions that led to it. This is desirable in and of itself.
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But why?? That ship sailed long ago. By now it's a feature on higher end civilian equipment to work with all the GPS-type birds up there as the more satellites you can see the more accurate your fix. My backcountry gear specifically lists this as a feature.
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That the researchers will go "challenge, accepted" on this and keep digging into leaves plenty of work cut out for them. Will be interesting to see what they can pick up from Amazon next. Also have to wonder how closely the constellation designers are watching this research for changing implementations.
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Sounds lovely, but for a company like SpaceX who exactly would have payed those employees for the years before it turned a profit if the employees owned the company?
it's not like it's impossible for co-ops and partnerships to exist. In retail they can be reasonably competitive and in professional services like law and accountancy they're by far the most successful model.
But I guess partnerships are insufficiently egalitarian since not all the employees own equity and neither partnerships nor co-p[s have ever done well in businesses that require large amounts of cap-ex with an uncertain return at the end.
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When the Falcon Heavy's maiden flight made headlines worldwide, the government discovered that SpaceX was broadcasting the launches from orbit. The government immediately banned these broadcasts as illegal spy satellites. Only after Musk's behind-the-scenes negotiations were the broadcasts restored, but with significantly poorer image quality.
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I don’t think American law is as obligatory as it used to be, especially when the CEO gave massive donations to the GOP.
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If you have a Samsung phone with Dex, this is definitely possible if you plug a portable monitor or XR glasses into it. There is an option to turn your phone into a trackpad, and it works prefectly.
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I'm that old: I learned FORTRAN on an IBM 7094 with core in oil. On punch cards, that I had to punch using an IBM 029 card punch, and I also used an IBM 026 card punch on occasion.Bah - when I was at college we had a big stack of punch cards formatted for FORTRAN
which I used as really nice bookmarks because I'm old but not that old
I probably had to watch out for dinosaurs on my way to school, but my memory is getting so bad I can't remember.
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The reason seems obvious to me. The war in Ukraine has already shown Shahed-136 / Geran-2 equipped with Starlink terminals for control and navigation purposes.
Undoubtedly, the Russians are supplying parts to the Iranians via the Caspian Sea (and vice versa). They are certainly sharing information, too.
As a superpower involved in an open war that has depleted my stock of anti-air missiles on cheap drones and ballistic missiles, I would be concerned by a PNT capability that I cannot effectively jam with electronic warfare.
Undoubtedly, the Russians are supplying parts to the Iranians via the Caspian Sea (and vice versa). They are certainly sharing information, too.
As a superpower involved in an open war that has depleted my stock of anti-air missiles on cheap drones and ballistic missiles, I would be concerned by a PNT capability that I cannot effectively jam with electronic warfare.
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