Hacker News

by Ryan Harman

GPS glitched across the US by as much as 33 feet (sciencealert.com)

151 points by thread_id a day ago

chaps 8 hours ago

This is exactly the sort of thing that leads to people getting reincarcerated after their electronic monitoring devices mistakenly report them leaving their homes.

Some reporting I did on the topic a few years back: https://chicagoreader.com/news/many-on-house-arrest-in-cook-...

dataflow 6 hours ago

> This

As in, GPS being off by 33 feet?

> leads to people getting reincarcerated

I'm reading your article and it seems to be about police coming to check and realizing that the reporting of being miles away was in error, not people getting reincarcerted because of GPS incorrectly reporting they moved ~30 feet too far? One of these is much more insane than the other.

iamshs 5 hours ago

The story is about GPS errors which end up making life hell for people under monitoring since they end up generating a Police response. If 80% alerts were false, then an error like this can result in a surge of these alerts. It is an important story to tell.

zamadatix 31 minutes ago

chaps 5 hours ago

Not sure where your confusion is coming from. Have you never used GPS in a place with bad signal? Where it gets confused and you miss your turn? It's the same failure mode. Just the repercussions are getting arrested instead of getting off on the wrong exit.

Also wrote this one, hopefully it helps your confusion: https://chicagoreader.com/news/false-alarms/

saaaaaam 5 hours ago

dataflow 5 hours ago

avazhi 5 hours ago

userbinator an hour ago

I misread that as "people getting reincarnated" and was momentarily very confused.

wetoastfood an hour ago

Probably more beneficial than "people getting reincinerated" which is how I almost read it but thought that couldn't possibly be it.

Aurornis 3 hours ago

Geofence monitors have buffer zones because a small GPS on someone’s ankle inside a house, potentially a high rise, isn’t going to be that precise.

33 feet is well within the allowances IIRC. Varies by state.

qlte an hour ago

According to this firm selling them, this model has <15ft error, usually 3-4 ft. Given the permissible area is entirely up to what the judge orders, it seems eminently plausible that someone confined to their apartment could be placed outside with a 33ft jump causing a false alarm.

At the very least, it's not enough evidence provided to claim the scenario is inherently impossible based on undefined "allowances" without any actual numbers for something completely dependent on the jurisdiction, monitoring software implementation, and attitude of the police officer/judge.

https://www.youtube.com/shorts/o0sPXL9C53g

I also found Reddit anecdotes of getting alert texts stepping outside onto the street from their yard, or false alarms while still inside but not enough details were provided to be sure they were actually GPS and not RF so not as helpful.

chaps an hour ago

chaps 3 hours ago

That might be true for a place in the middle of nowhere with no features, the same device model managed by the same company and the same call center person and same sheriff and judges and prosecutor. But with GPS in an urban environment where many homes are over 100 years built from many different materials, 33 feet is a lot.

Aurornis 3 hours ago

cromka 7 hours ago

Sounds like you could be a convict, have your gang interfere GPS on a local level but enough to have other people in the neighborhood notice, make a quick run for whatever you'd need to, and still claim plausible deniability.

john01dav 7 hours ago

Or you could cause such localized things more so to try to get a person sent back to prison or otherwise penalized intentionally

cromka 7 hours ago

gm678 10 minutes ago

Related:

https://news.ycombinator.com/item?id=49500504 Cheap GPS jammers are filling the world with navigation dead zones (wsj.com) 3 days ago

https://news.ycombinator.com/item?id=48606271 Satellite reveals immense scale of GPS signal tampering (space.com) 3 months ago

MarkusQ 6 hours ago

TFA article claims: "Indeed, the solar storm of May 2024 is estimated to have cost the US agricultural industry $500 million due to disruptions in precision navigation."

This seems hard to believe. The link provided hand waves through how it maybe could happen, and ends with an Economist just SWAGing that it could have been maybe a dollar an acre or so.

"He estimates that affected farms lost about $1 per acre. Nationally, this equates to an estimated half-billion dollars in lost earning potential, Griffin says."

So yeah, hard to believe was the right call. Very few farms were affected, but if we assume half of the total 900 million acres of farm land were, add 10% to get a round number, and guess it at a dollar per acre, we get the quoted big number.

sen 6 hours ago

That’s how all “estimated damages” work. It’s all just made up by some random person who guesstimated a number then multiplied it by the maximum possible people effected, realistic or not.

CGMthrowaway 3 hours ago

Tell me "it's different" with this one please https://sustainability.stanford.edu/news/study-links-past-em...

Waterluvian 6 hours ago

There’s probably a reasonable methodology but it has a lot of multiplications and some base parameters that make the whole thing wildly sensitive.

qlte an hour ago

f1ay an hour ago

It seems worth mentioning that the last time GPS had issues like this afaik, it was due to the US utilizing 'selective availability' due to national security issues. We used it somewhat famously during the 9/11 attacks.

Also the page 404's via archive.org, but information formerly from gps.gov can still be found here: https://archive.ph/trwOo

Edit: The selective availability page moved to https://www.gps.gov/selective-availability

nwbear90 5 hours ago

An interesting warning as Austin is blanketed by Cybercabs. I think a town full of golden driverless cars 33 feet from where they think they should be is terrifying.

John7878781 5 hours ago

I would be shocked if Cybercabs solely rely on GPS for positioning. I imagine they look at their surrondings, etc.

1e1a 9 hours ago

Wouldn't RTK help mitigate this, as the base stations would also be affected by the atmospheric disturbance?

entrope 3 hours ago

Yes. WAAS should also help a lot, or at least tell you that you can't get a good position.

jplona 4 hours ago

I think so, yes. That's the main purpose of RTK

ashleyn 8 hours ago

Somehow, Selective Availability returned.

Quibblingeek 5 hours ago

Maybe not intentionally (at least by the U.S. Government, but the consequences are far greater now.

Now that GPS has subsumed a large part of air navigation as more VOR and ILS approaches at non-towered airports are being left to fall into disrepair, it forces more and more aircraft operating in instrument conditions to fall back to a navigation system that may not operate to the tolerances that you need to shoot an approach to LPV minimums (which puts you close to 200 feet or so above the ground) or LNAV minimums (higher, but still pretty low to the ground). If you lose signal integrity, you abort the approach. You don't want to break out at minimums only to find that the runway is 33 feet to the left or right of the centerline when it's not a circling only approach where you're expecting it. If that field only has RNAV (GPS) approaches, you have to divert. Hopefully the alternate airport you filed has a ground based approach plate available that is authorized .

When SA was around, we had more VORs, more VOR and ILS approaches, and while NDBs (decades old radionavigation beacon that operated on the AM band) were on their way out, they were still around.

ashleyn 4 hours ago

One of the reasons SA was discontinued was that if you knew the coordinates of a base station, you could correct for the error. Are airports not doing this already?

Quibblingeek 3 hours ago

delta_p_delta_x 9 hours ago

*10 metres

blululu 2 hours ago

Obligatory: https://www.xkcd.com/3248/

nubinetwork 2 hours ago

The gps on my phone drifts by a few city blocks all the time...

NooneAtAll3 9 hours ago

were other satellite positioning systems affected as well? was it checked that it wasn't just a misconfig on US command side?

mcpherrinm 9 hours ago

The linked actual research article did look at multiple GNSS systems. GPS is presumably being reported out of familiarity https://doi.org/10.1029/2026GL124645

Insimwytim 9 hours ago

TL;DR:

1. Not today. November 2025. They don't make it clear.

1.1. One would expect that to be put in the title, when the article is written almost a year after that.

1.2. No, the article doesn't state that in the first paragraph. Posting in it full seem to be the only way to fend off lazy comments:

  In November 2025, Earth was buffeted by several massive eruptions of solar material that slammed into the magnetosphere.
That's it - the whole paragraph. Several paragraphs later - GPS first mentioned. No clear links between dates stated.

2. It is unclear what is the source of the claim.

UPD: Commenter below found the source, but TFA doesn't make a good job of presenting that as a source of the 33 feet glitch claim, but rather posts another citation from it.

They should've just quote this and be done with it:

  During the storm main phase, an east–west elongated band of intense auroral brightness expanded equatorward, producing a horizontally extended strip of strong density gradients that favored the development of small-scale irregularities. These small-scale irregularities triggered pronounced amplitude scintillations (S4 > 0.5) and caused significant positioning errors exceeding 10 m—large enough to disrupt GNSS-dependent applications across CONUS for hours, particularly precision agriculture and autonomous transportation industries. [1]
3. Navigation issues happened before, they state it right there. They were more disruptive as well.

4. The author has articles all over the topics. Everything is sensationalized.

5. Every presented link seem to have this awful Cloudflare js challenge.

Bad article overall.

P.S. Response to the false claim below - no, there's nothing about GPS in "the first 3 words of the article".

[1] https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2026GL12...

kbelder 7 hours ago

>P.S. A separate comment would be too much to respond to the false claim below - no, there's nothing about GPS in "the first 3 words of the article".

He's talking about your first (incorrect) claim. The article begins "In November 2025"

nomel 8 hours ago

> 2. It is unclear what is the source of the claim.

7th paragraph of the article states the source, and contains a link to research paper where they go into great detail.

Elidrake24 9 hours ago

> Not today. November 2025. They don't make it clear.

My brother in christ it's the first 3 words of the article.

gerdesj 6 hours ago

Their first line is TL;DR!

ck2 9 hours ago

not just space weather, I am pretty sure the atmosphere is being disturbed by toxic human activity both by accident and on purpose

I've run outside every morning for decades and used Garmin with GPS since 2015, I've never had so much trouble

Garmins finally supports dual-band (L1+L5) and BeiDou on newest models but it's still not enough to compensate, I have to use a Stryd footpod to guarantee accurate distances/speed

btw BeiDou GPS blows away US GPS for number of sats and precision but despite Russia's GPS being legal in US, technically BeiDou is not

* https://warontherocks.com/a-signal-point-of-failure-integrat...

* https://payloadspace.com/gps-faces-growing-competition-from-...

* https://en.wikipedia.org/wiki/BeiDou#GPS_vs._BeiDou_Capabili...

z2 9 hours ago

For resiliency reasons alone, it's been proposed to allow (stop software-disabling) BeiDou in the US, but the last time this was brought up, the administration ran out of time. It's a shame, because when there is precise coverage, it enables things like lane-level city navigation.

https://warontherocks.com/a-signal-point-of-failure-integrat...

ck2 8 hours ago

yup that was my first link

but of course this administration is never going allow China-anything like low cost electric cars even if it means saving people a fortune in gas

so hopefully in 2029 it can be looked at again

or maybe Dems will also get the Senate too and can be petitioned if they run out of corruption investigations before 2029

it is critical to explain to everyone who isn't technical that GPS is "read only" and no data is being sent to China via BeiDou (just like it's not sent to Russia's Glonass) because that apparently is some kind of weird misunderstanding

on that same note if they somehow made Starlink into a lower resolution GPS backup I'd even trust that too despite personally being anti-Musk everything

z2 4 hours ago

bigfudge 6 hours ago

arijun 8 hours ago

> BeiDou GPS blows away US GPS for number of sats and precision

Both BeiDou and GPS are supposed to be limited to 10m precision for civilians.

But, going down a rabbit hole, I found that BeiDou is way more accurate than 10m--3.6m and 2.6m outside and inside the Asia-Pacific region, respectively [1]. And that's with the most simple algorithm. It goes down to ~2.5m using dual-frequencies to account for atmospheric error.

[1] https://www.nature.com/articles/s41598-022-12012-y

myself248 8 hours ago

> Both BeiDou and GPS are supposed to be limited to 10m precision for civilians.

Maybe in 1998, but Selective Availability was turned off in 2000, and here in the modern era: https://rtklibexplorer.wordpress.com/2024/04/28/dual-frequen...

arijun 8 hours ago

rcxdude 5 hours ago

With a base station in a known position you can get to cm resolution with somewhat pricey but decidedly hobbyist-accessible gear: https://www.sparkfun.com/sparkfun-gps-rtk-sma-breakout-zed-f...

arijun 8 hours ago

It seems that all the device manufacturers (they mention Apple, Samsung, and Google) are using BeiDou anyway. I don't know if that includes Garmin watches, though.

https://www.reuters.com/technology/us-agency-probes-risks-fo...

rzzzt 7 hours ago

AGPS also helps if you have cell towers nearby.

askvictor 4 hours ago