Posted by thread_id 1 day ago
Some reporting I did on the topic a few years back: https://chicagoreader.com/news/many-on-house-arrest-in-cook-...
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.
Also wrote this one, hopefully it helps your confusion: https://chicagoreader.com/news/false-alarms/
> Harkins said that since last October, she has seen 30-40 people ordered back into custody based on these progress reports. When asked what can be done to improve CCSO’s EM program, Harkins said that the sheriff’s office needs to “properly and fully” investigate alleged violations before writing reports or taking actions.
To be explicit: yes, many, many, many people were reinarcerated because of faulty GPS.
I'm talking about the class of problem. It happens in normal weather conditions and things like this exacerbate the problem.
Really not sure what the hostility's about.
But maybe you posted the wrong one to begin with.
Let’s all be friends and nice to each other.
A single 33 foot anomaly is already within the geofence buffer zones used. In dense urban areas the geofence buffer allowance may be 10X that already.
Yes, yes I am. You really need to realize just how unbelievably fucking arbitrary the criminal courts are. At every level. They're not tech people.
To answer your question, I have examples of motions by prosecutors to suspend people from the EM program where they specifically cite specific data points just barely out of their homes, where video footage provably shows they were inside the whole time. They're not mine to share.
Btw, the courts are public and you should try some criminal courts watching. Pick a random day and just go.
Looking forward!
> motions by prosecutors
Motion ≠ incarceration. So, not an answer (yet?)...
Did defendants get incarcerated as a result of these motions, or no?
Something about this just doesn't seem very plausible, especially if this kind of thing is happening more than once in a blue moon. Either the video evidence is not as convincing as we're being led to assume (thus leaving more doubt in the judge's mind than ours, even if the person is innocent), or there should be some other explanation.
Lawyers began telling their clients to film themselves in their homes at all times so that they could prove to judges that they were in their homes when the devices went off. That's advice they give because the risks of not doing that are going back into jail. But you still have to go through all that process, filming yourself, etc. It's truly bad.
So you could find an example easily but you don't want to? Or you're suggesting court watching in general and not to find an example?
"I have an example I won't share" is better than nothing, I guess. But you were being snarky before you even said that much, when you were just linking your article and not saying if examples existed at all.
I'm curious why they're not yours to share, though. Did someone give them to you under private circumstances, or can people get there from public information but you think you shouldn't spread the word?
A lot of this stuff is hard to talk about because it's about real people in real pending (at the time) cases.. and I'm also not a criminal defense attorney by any means. There's a reason the first article I posted had their identity completely removed. There's weird liability and believe me I want to say more.
Very honestly, I wish I could have done more reporting on how fucked up those devices were. I put a lot of time and effort into reporting that couldn't make it to print, largely because I was doing freelance work at the time. The first offer I got for that piece was $50. Wasn't sustainable.
Do you have any questions about these EM programs?
Not really sure what it has to do with tech though. That’s a problem with how certain humans behave, not ancillary technology.
You and I have very divergent views of the type of person likely to be charged or prosecuted for a crime or indeed to participate in a diversion program that involves GPS trackers, my friend.
Meaning an error like this harms innocent people wrongly accused more than the stereotypically hardened repeat offenders you imagine to be undeserving of your sympathy and presumed guilty.
Non-violent, first-time offenders don't get ankle monitors. But thank you for highlighting my point.
Like, actual lol mate.
Yours (inferred) is "Too Much : Zero".
Given that those are terminal values it would challenging for literally-any-other-view not to diverge from yours, on this.
33 feet is well within the allowances IIRC. Varies by state.
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.
The story you linked has examples about false alerts triggering in a different state.
Do you have any actual examples of 33 feet getting someone arrested? I’ve worked enough with GPS that I could tell you that any system with thresholds that low would result in everyone getting false triggers
I fought tooth and nail to get access to the data showing how often devices reported "invalid" status (where the device's specs said it was something like, within 150 feet of inaccuracy it reported "invalid"). They initially told me they couldn't get me that data because it'd crash their database running that query. Basically threatened to sue them and over the next 6mo or so I got two 100GB MSSQL dumps. Hundreds of millions of rows of devices reporting back that their GPS signal was invalid. It would take a lot of time to make it sharable because they included the actual GPS location infos.
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
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.
https://farmdocdaily.illinois.edu/2024/05/how-will-the-gps-o...
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
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.
To that, you can augment something called GBAS (we used to call it Local Area Augmentation System but switched over to the ICAO name for it). It’s basically a ground station that sits at an airport and corrects for GPS errors where you need it most (airports definitely qualify here and that’s where you need the best GPS performance).
Ultimately, the FAA is going to go 100% GPS and it’ll fall back to the minimum number of land-based sources for redundancy. It’s about cost. The issues with GPS may cause them to push the timeline back and develop plans to mitigate the issue, but they’re too far down this path to stop now.
If one has a lot of patience, one can read the details of how it works at https://elibrary.icao.int/product/299828 (along with SBAS, the ICAO name for what WAAS does; the constellations they can augment; GRAS, a weird hybrid between GBAS and SBAS that apparently went nowhere; ILS; VOR; DME; and VHF marker beacons). Annex 10 Vol I probably doesn't say explicitly that triple redundancy is required, because if you had a single receiver with an MTBF of something like 10 billion hours then you could use just that one.
This particular 30-foot error should go away almost entirely for future receivers that implement DFMC SBAS or ARAIM.