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bronco21016 21 hours ago [-]
Whats really sad for aviation is there was already an extensive network of ground based navaids. As GPS has proliferated, they've slowly been decommissioned as they age out to save on cost. I'm specifically referring to VORs which provide azimuth and range to station.
GPS is fantastic and as a primary source everyone loves the benefits it brings. However, in a century of aviation, everyone has kinda sorted out that you can't have too many backups to critical items... unless you let the accountants and bureaucrats run the show.
buildsjets 21 hours ago [-]
VOR is extremely short range and requires an extraordinary number of transmitters to provide any volume of coverage. Additionally it cannot provide coverage over oceanic areas. We USED TO have a nearly global long-range land based navigation system called LORAN, which only required one master station and a few remote stations to provide continent-scale coverage. But it was decommissioned in a cost savings move after it was determined that it could be replaced by GPS. It worked perfectly fine until it was decommissioned in 2010, not that long ago.
In the '90s I used to fly light aircraft back and forth between Seattle and Alaska. You were frequently out of range of any VOR transmitters, but that LORAN always worked.
NDBs? That didn't work so great for Ron Brown.
On VOR: It's also a PITA to use, and for inexperienced people, or someone who rarely uses it, they can confuse flying towards and away from the station.
buildsjets 19 hours ago [-]
If you are a general aviation goober like me, flying a 1960's propeller airplane, sure, that is true.
However, in a modern commercial aircraft, all position sources including VOR-DMEs, GPS, and IRS are cross-compared by the flight management system and turned into a latitude, longitude, and circular error of probability. There is no TO/FROM flag to worry about in a 777, and no reverse sensing on the back side of a localizer approach.
verelo 19 hours ago [-]
Yeah that makes sense. My experience is mostly in 70s to early 90's prop planes, I have had the opportunity to use a glass cockpit a few times and it was much easier. I guess i did the typical thing and contextualized this on my experiences and ignored that 99.9% of flights are not GA haha.
_moof 19 hours ago [-]
Time was, if you didn't understand how to use VORs, you couldn't really fly. We used them as primary en route nav, as well as for approaches, for many decades. As a CFI I think most of the confusion around VORs these days comes down to poor or inadequate training.
verelo 19 hours ago [-]
That's fair. I replied to someone else with a similar remark, but essentially doing most of my flying in 70s to 90s prop planes, I imagine the tools I'm most used to are just dated. Your point around training is likely very accurate, I had some great teachers but I also had a few instances of being given inaccurate information and having to teach the teacher so to speak.
ryandrake 2 minutes ago [-]
A lot of those planes still exist and have not gotten panel upgrades, so IMO you still should learn how to navigate purely via only visual references and radio navigation. I believe you are still required to know how to use them to pass your private pilot check ride, too, but I may be wrong.
Charon77 14 hours ago [-]
I don't fly and I wouldn't call my self someone that plays a lot of flight simulator. But I do enjoy navigation methods and I did learn the basics and practices of VOR navigation. I got an Android app that simulates flying courses, holding patterns etc, but only the navigation part. I would say I learned some intuition to it.
mschuster91 20 hours ago [-]
> Additionally it cannot provide coverage over oceanic areas.
It's really hard to jam oceanic areas though, you need a vessel capable of sustaining human life autonomously at least for days plus dealing with the high seas.
Buoys could theoretically be used for that purpose, yes, but good luck getting them stationary enough. Maybe some of the secret services could pull off such a trick but at least no ordinary civilian.
_moof 19 hours ago [-]
> sustaining human life
Not really. Drone ships are very much a thing these days.
vanviegen 10 hours ago [-]
How can a drone ship hold its designated position while it's blocking gps?
K0balt 4 hours ago [-]
By stopping jamming for a few seconds every few hours , and navigating using dead reckoning in between? With just a compass, a log, and a watch I can sail for days and end up within two kilometers of my destination.
tisizi 8 hours ago [-]
Shouldn't it be possible for you to reconstruct the original GPS signal if you can control the jamming pattern?
aeonik 4 hours ago [-]
Eh, I doubt it, GPS signal is so weak, once the EM field in the air has so much power, I think the literal hardware ADC of any receiver would be overwhelmed/clipped with a high power jammer nearby. I mean it's possible that the front end will be literally fried, not just clipping the analog front end. GPS is usually -130dBM, it's absurdly weak.
But in theory you're not wrong.
waste_monk 7 hours ago [-]
Anchor? ;)
egberts1 6 hours ago [-]
Electro-mechanical gyroscope
ludston 7 hours ago [-]
Probably just turn off the jammer for 2 seconds
Intermernet 9 hours ago [-]
Astral navigation is probably accurate enough
K0balt 4 hours ago [-]
Dead reckoning with a minute or two to get a gps fix with the jammer off once a day.
AdamN 8 hours ago [-]
accelerometers can do that job. Also it can stop the jamming every once in a while to check.
dotancohen 3 hours ago [-]
INS
andix 1 hours ago [-]
Are there modern positioning systems that can automatically join all those data sources into one position? Traditionally navaids are treated as completely separate sources and are shown on different kind of instruments. But they could also be used as a replacement source for GNSS data on a modern map screen.
Depending on their kind they might not return a specific position, but in combination with other sources they often do via triangulation.
PS: INS (Inertial Navigation) also still exits. It often works for quite a long time really precisely. Also precision can be calculated. So it can start as a dot on a map which becomes a bigger circle as the precision decreases. It could be automatically recalibrated whenever high confidence positioning is available.
bronco21016 53 minutes ago [-]
Yes, modern flight management computers in commercial airliners do exactly this. I can't speak to smaller aircraft.
Essentially a position is calculated from VOR/DME, GPS, and INS. When there is disagreement it is flagged and procedures are in place to fall back.
The issue is VOR/DME is slowly being decommissioned eliminating one of those sanity checks. It hasn't been degraded to the point of creating massive gaps in coverage over land but it will slowly happen if the rate of decommissioning continues.
Ultimately, INS is sufficient for enroute navigation but if you're degraded to just that state, the impacts to traffic separation, particularly in congested airspace, are significant. Required Navigation Performance (RNP) levels dictate all of this.
mzi 4 hours ago [-]
A bunch of us old salty sailing nerds were actually discussing Decca Navigator System¹ the other day that was still very present in the 90s on the ships we were sailing. Now all replaced and removed.
Oh, wow! That seems to fill a gap below LORAN's range, and far exceeding its accuracy. I never heard of it before!
KaiserPro 3 hours ago [-]
Sorry but this sounds like nostalgia. loran-c was prone to error.
Yes, we can stop that with modern tech, but the problem with loran-c is you had location ambiguities. Decca was worse, unless you had a good initial fix, you were all sorts of fucked. There are of course modern alternatives, but they are not block proof, or turned on.
There is a very good reason why GPS was opened up, because the alternatives were not anywhere near as good.
Now, what are the alternatives? well hyperbolic navigation is still a thing, and with modern electronics you can get a pretty good fix without any of the nasty ambiguaty that loran-c had. If you are flying over land, then visual odometry is now at a point where you can locate pretty accurately autonomously (assuming cloud cover is your firend)
Small low power ceasium clocks are $4k now, and only really need a few hundred millitwatts to run, which opens up a whole load of other ways to navigate.
then there are IMUs, they are dirt cheap and way more accurate than 20 years ago. A calibrated array should be able to sustain reasonable accuracy after 30 minutes now
m463 15 hours ago [-]
maybe we need to update those giant concrete arrows on the ground...
You're not far off with the QR codes. Some military hardware actually match camera input to known maps to navigate. Mostly unmanned, one-way hardware.
sokoloff 20 hours ago [-]
All VORs provide a radial that you’re on. Not all provide a distance to the station. VOR/DME or VORTACs provide both. Plain VORs do not.
As more and more are decommissioned, the percentage that support distance-measuring goes up, as the ones being decommissioned are more likely to be the less-useful ones, which are less likely to have supported DME in the first place. So most remaining ones support both, but it’s not assured without checking.
flewbee 12 hours ago [-]
By taking a bearing from TWO VORs simultaneously, the distance to each can be computed. That's why planes have two VOR receivers and instruments.
sokoloff 2 hours ago [-]
Two VOR stations will give you a fix, but since GPS took over from legacy RNAV, that’s now rarely used operationally in the US.
More common is to use Nav2 tuned to a VOR to find an intersection on the arrival and Nav 1 to fly the final (ILS/LOC/VOR).
jshier 20 hours ago [-]
Seems like we'd need a modern version that's less susceptible to jamming, otherwise aren't we just replacing one jammable service with another?
michaelt 19 hours ago [-]
There are two types of GPS jamming.
There's GPS jamming by the military, mostly in war zones. This seldom effects airliners because they steer clear of active war zones.
Then there's GPS jamming by delivery drivers who don't want their boss watching over their shoulder all the time. When the article mentions jammers as small as a cellphone and costing less than $100, those are sold to drivers.
Delivery drivers don't jam LORAN or VOR, though - so it's not jammed by the second type.
bb88 18 hours ago [-]
GPS jamming was being investigated by the NTSB as a possible reason for this air crash that killed 4 people near White Sands Missile Range.
The plane reported GPS signal loss 5 minutes after the jamming started by WSMR. Three other planes in the area also reported GPS loss.
I’d bet a lot of money that the NTSB will determine that the pilots’ failure to maintain clearance from terrain during a visual approach will be the primary cause with contributing factors of dark, moonless night and GPS jamming.
That one’s going to be on the flight crew, not the GPS jamming test.
I'm not going to argue that as it's always easy to blame dead people, but there's two different types of jamming.
One is to actually jam the signal IOW preventing reception. The other is to overpower the satellites' signals and replace them with your own. That defeats the doppler calculations of GPS needed for triangulation, and instead the receiver believes it's where the jammer wants it to be.
If the latter includes altitude information, then it's a huge problem.
sokoloff 13 hours ago [-]
I believe it’s been made public that this was a jamming test, not a spoofing test.
bb88 12 hours ago [-]
If you overpower a signal, is there a difference? I'm not saying you're right or wrong here. I'm just saying there's a long history of coverups in the government and military.
If you can say, "oh we were only jamming" when in fact you were spoofing, well that's certainly a super easy excuse to hide behind.
sokoloff 12 hours ago [-]
In either case, asking for and being cleared for a visual approach (as the crew did and was) puts the onus on them to maintain continuous visual contact with the airport and to maintain their own terrain and obstacle clearance, which it’s safe to say they didn’t do.
542354234235 3 hours ago [-]
>If you overpower a signal, is there a difference?
Yes, obviously. Losing signal on your GPS unit, and having your GPS unit tell you that you are in a different position than you actually are, are two very different things.
Also, since other aircraft reported GPS issues, that is evidence that would speak to jamming or spoofing. All three other aircraft reported a loss of GPS, not inaccurate GPS. Coverups are real, government conspiracies are real. But the completely evidenceless “I’m just saying…” or “isn’t it weird…” or “I’m just asking questions” is tiresome.
matheusmoreira 10 hours ago [-]
> boss watching over their shoulder all the time
Sounds like the root cause to me. It should be illegal to use GNSS to track employees, or anyone really.
Jamming is starting to sound a lot like self-defense against surveillance.
DeepSeaTortoise 8 hours ago [-]
IMO tracking is just way too useful. You know when things are about to arrive (so you dont miss a parcel because you went to the toilet or you can even intercept your driver once he's in the area, removing most of the last-mile problem), routes can be changed on the fly (e.g. for on-demand public transport pickup, trunking or delay mitigation) or, well, you can track your vehicles, allowing you to find them quickly in case of theft, optimize routes or have decent evidence in case of disputes.
The real problem is not really drivers being tracked, but how the tracking data is or might be used. Timestamped delivery notifications might be just as bad in this regard.
As often, the solution is probably more about accessible and pro-human law. No idea how that should work, maybe certain sensitive data services having to be provided by a third party or even the government itself? There are probably much smarter ideas or variations of this...
XorNot 7 hours ago [-]
Is this even a real scenario though? A data logger is going to notice hours of GPS outage during your working hours.
15155 2 hours ago [-]
So as a business owner, I'm not allowed to know where my $100,000 asset is? My insurance carrier requires me to track the vehicle as a condition of coverage, they also require a dashcam be operating at all times.
torginus 9 hours ago [-]
Antenna tech has moved way beyond what was possible in the days GPS was invented. Planar arrays and MIMO are ubiquitous and cheap.
These antennas have a very good idea of where the signal is coming from, due to delay measurements and can detect and filter ambient noise. They are super hard to jam. The reason why drones have become such a PITA is that these inexpensive antennas are very hard to defeat even with military jammers.
If this becomes a geniune need in the civilian sector, then I'm sure the tech is up to the challenge.
minetest2048 8 hours ago [-]
The tech is already there, but the reason those antenna are not widely used is that they used to fall under ITAR, so no US companies want to touch those for civilian uses. Of course Turkey and China is not US so they don't give a damn about ITAR compliance, and so you can buy those anti jam antennas out of alibaba.
Brad Parkinson, the father of GPS and PNTAB, they've been trying to lobby the US government to remove ITAR from that technology so the civilian can benefit from anti jamming, and finally they managed to do it sometime last year. Now it falls under EAR
torginus 5 hours ago [-]
There's also a bunch of Western stuff you can buy off the shelves. MIMO tech is standard in every Wifi 5+ router, Cars have pretty sophisticated electronically steered radars nowadays, boats even more so. 5G towers also have phased array antennas. This tech is everywhere in consumer or industrial stuff.
Not sure what makes an antenna/sensor ITAR restricted, I suspect if you try optimizing it to military use-cases, you'll get hit with ITAR, but I suspect Brad Parkinson is right - security through obscurity just doesn't cut it any more.
I remember in the 90s, computer security was either missing or an afterthought (you could bypass the Win98 password prompt by pressing escape in the release version). Thankfully the industry got together and figured it out.
Now everyone else needs to follow suit. We already have a bunch of examples of assuming security does not matter (hackable cars, meters that can be switched with a Flipper zero).
Gigachad 11 hours ago [-]
GPS jamming is fairly detectable right? I wonder if we could create some crowd souced map of jammers. I think this kind of already exists as fairly course data but if a bunch of people installed fixed GPS sensors at home and wired them up to note every time their location lock is lost or moves. It could create a hyper detailed map of where the jammers are and track them moving in realtime.
michaelt 9 hours ago [-]
> if a bunch of people installed fixed GPS sensors at home
Similar things already exist - although it's used for increasing GPS precision and detecting faulty satellites, moreso than detecting jamming, so the networks might not be dense enough to detect small areas of jamming.
For one state's example, see [1] - choose 'RINEX archives' if you want historical readings.
They're easy to find, but not necessarily with stuff from off the shelf. Professionals with the right equipment though have no trouble locating them. The FCC is happy to hand out 5 and 6 digit fines for operating a GPS jammer and has fined retailers tens of millions for selling them.
Gigachad 9 hours ago [-]
If you wanted to exactly pinpoint it with a single device sure, but I'm thinking of a map where nodes just report that they are experiencing jamming, and then with the whole network you can see a radius of the jam, see it moving around, and assume it's somewhere in the center. All with cheap off the shelf hardware.
The police could probably combine this data with license plate scanners and see the single truck that always exists in the jammed location.
cucumber3732842 5 hours ago [-]
I know we all like to jack ourselves raw to the big powerful government handing out ruinous fines for things we don't like but realistically none of that is gonna stick to some McDonalds manager who's got a side gig importing Alibaba stuff or some delivery driver who bought it. You can't get blood from a stone. You're just guaranteeing the stone always stays a stone.
Yeah the FCC could probably pull an ATF and shoot a bunch of people over fairly petty crimes but that costs political goodwill that I'm not sure the FCC has to burn.
kayodelycaon 55 minutes ago [-]
The FCC takes the public commons very seriously. Given how easy it is to make radio frequencies unusable, they need to hammer hard and fast to discourage people from trying. They don’t wait for a report to be filed, they can proactively search for violators. They may only be able to fine you but they can get law-enforcement involved. Especially if your city or state has laws against what you’re doing. You usually see this when you start messing with airplanes.
Yesterday's actions include 7 $25k fines apparently all for companies illegally importing banned drones (a procedural fine just for ignoring the investigation attempts). You can peruse that list and find plenty of things, lots of pirate radio recently. They absolutely do go after apparent small fry and your "mcdonalds manager" absolutely has assets that can be seized.
>Yeah the FCC could probably pull an ATF and shoot a bunch of people over fairly petty crimes but that costs political goodwill that I'm not sure the FCC has to burn.
The FCC doesn't have guns, they can't arrest you
torginus 9 hours ago [-]
If I was a concerned boss, I would likely use GSM cell info to track my drivers. While not good enough to do turn-to-turn navigation it certainly is good enough to tell where people are.
Btw, don't smartphones have this built in? I remember some old and cheap Android phones without GPS that came with this.
kayodelycaon 1 hours ago [-]
I believe they do. It’s used to get an initial fix before you get gps coordinates. Wifi network names in range might also be used.
pigggg 11 hours ago [-]
Eh a month or two before the October 2023 Israel conflict - there were many reports of GPS jamming in the middle east impacting air transport aircraft. To the point where it basically caused various failure modes that shouldn't have happened with avionics (think the things you'd expect in a fuzzing scenario). It was pretty eye opening example of just how poor modern avionics are (and their integrations) when they get unpredictable inputs & the dependant downrange systems that rely upon that data.
dzhiurgis 9 hours ago [-]
Russia has a satellite constellation for global jamming.
dylanger 7 hours ago [-]
[dead]
azernik 19 hours ago [-]
Being much closer to the receiver and tied into terrestrial power grids, ground-based beacons can transmit at higher powers than GNSS signals and be received at much higher powers.
Received GNSS power is on the order of -130dBm (10e-16 W) - you can jam that with a 1W terrestrial source for hundreds of meters around. Way more if you're willing to scale the power from car USB power levels to bigger grid-connected supplies.
LORAN, from my quick googling, looks to be about 6-7 orders of magnitude higher received power.
torginus 9 hours ago [-]
What about terrain following? I would guess decent topographical maps of the world aren't that hard to come by today, to get a good idea of where you are.
Although that approach depends on you being able to see the ground neither of which is guaranteed over a body of water or in poor visibility.
KeplerBoy 8 hours ago [-]
Entirely possible and poor visibility is not an issue if you have radar.
atoav 8 hours ago [-]
My guess would be that the best solution is multi sensorial anyways. So you have GPS, but then you would have an Inertial Measurement Unit, based purely on acceleration and inertia, radar and barometric systems and maybe optical systems for terrain identification and celestial navigation.
I have recently heard an episode of Amp Hour podcast¹ where they talked about using Bluetooth from satellites as a GPS replacement for asset tags. So maybe alternatives to GPS on different bands are on the verge.
Another interesting idea would be to have an antenna array on the plane that captures different radio sources and the angles from which they seem to come from and create a always updating radio activity map that maps a certain "radio landscape" to a position on the planet. AFAIK this is currently being worked on as well under the name "radio-SLAM" (with SLAM standing for Simultaneous Localization and Mapping). This means, jammers could maybe even be used as potential beacons themselves.
GPS signals are just incredibly weak so it takes next to nothing to drown them out, easier still if you are above the receiver.
toomuchtodo 20 hours ago [-]
I would be curious on and interested in guidance from a GNSS expert on what the risk profile is when you're using jam resistant frequencies with a multi GNSS constellation chipset (GPS, Galileo, BeiDou), WAAS (GNSS corrections received via satellite), and when close enough to airports that support it, LAAS (GNSS corrections broadcast from airports). Follow up questions would be what countermeasures are available to bolster GNSS reliability during critical phases of flight (takeoff and landing), as well as how cellular tower networks could be used as distributed sensor fabrics for constantly monitoring for and triangulate GNSS jamming using SDR (or perhaps start with a handful of GNSS reference monitoring stations at major airports for this monitoring).
Because GPS and other GNSS have only a very weak signal strength there are no jam resistant frequencies, you can jam them all very efficiently, or you can jam them very efficiently in selective way (jam BeiDou, but not GPS).
GPS was jammed even as early as Iraq war.
"Coalition troops also got a glimpse of GPS’s greatest weakness during the Gulf War. Iraqi forces installed jammers, for example, on top of landmarks such as Saddam Hussein’s palaces to prevent them from being hit, Mastalir says. This helped the military realize early on that it would have to further develop its laser-guided munitions and other weapons that acquire targets when GPS is unavailable"
A lot of work is being done to make GPS more jam resistant, and - just as important - more spoof resistant. The latest batch of satellites has a whole raft of countermeasures to help a receiver to identify whether the received signal is genuine or whether it was spoofed. Receivers too can do a lot to detect spoofing by just observing the signal (for instance: unrealistic power levels on reception, impossible response to vehicle movement and others besides), but quite a few of those are unrealistic or too expensive for regular (non military) applications. Jam resistant frequencies do not exist as you already mentioned, from a physics perspective. But GP might mean this to refer to the new M-Code signal, and these are sent out on different frequency offsets from the main carrier, so effectively different frequencies.
leonidasrup 19 hours ago [-]
Jam resistance and spoof resistantance are very different.
What work is done to make GPS more jam resistant?
jacquesm 18 hours ago [-]
L5 is considered to be more jam resistant, but it is still in the process of being rolled out and most receivers do not have that capability. It will take the better part of a decade to be rolled out completely but the space side should be done by 2027 so if you need it you can get it but you'll need a completely new receiver.
For obvious reasons hard information about all this is tricky to come by, you can read what is available from non-classified sources though and you can glean quite a bit from there.
The third edition of 'Kaplan' is still excellent reading on the subject even though it is 10 years old now.
toomuchtodo 18 hours ago [-]
> L5-band signals are 30x harder to jam and interfere with compared to L1, and they offer superior performance in difficult-to-navigate areas such as urban canyons and tree-covered regions.
If Russia’s proof of concept moves to active use, those satellites (Kosmos 2546 and any others) will need to be removed from service with anti satellite technology (either munition or X-37B equivilent). Clearly Russia is attempting to shield an overt military capability behind the satellite’s early warning launch detection primary mission to dissuade attempts to disable it. Remove the orbital capability, deny them access to replace it.
Ongoing Ukrainian strikes against Rassvet satellite production and launch sites contribute to further impairment of Russia's ability to get any new or replacement satellites to orbit.
I think Starshield (Starlink for the military) is going to use lasers as the means of communication (and location). Those are highly directionaly, and likely not possible to jam. Though I'm not sure how resistant are they to atmospheric interference, and the sats need to know where your receivers are, which I can't imagine the military is too happy about.
numpad0 14 hours ago [-]
Most pre-GPS navigation systems have shorter baselines than GPS and therefore accuracy is much worse, on top of generally being more complicated
cjbgkagh 16 hours ago [-]
Probably be easier and more reliable to use star navigation with modern cameras, computers and atomic clocks. Especially for commercial aircraft flying above the weather.
mike_d 16 hours ago [-]
Celestial navigation requires an accurate clock and an almanac that needs to be updated. It is completely impractical for non-military applications.
raron 13 hours ago [-]
Is that really that impractical?
With a quick calculation 50 ms time offset would mean about 20 meter difference. You can get that accuracy with NTP over residential internet and a better TCXO could hold that for a day. You could sync clocks and download the almanac at each airport. The almanac could be digitally signed and NTP has an option for authentication, too. That's about 10 USD of hardware (plus what you need for image capture and processing).
I'm pretty sure with dedicated hardware and better solutions you could get much better accuracy.
3eb7988a1663 13 hours ago [-]
They did it in the 60s for the B2 bomber[0]. I think computers are slightly faster and more reliable today, so it at least seems plausible.
Does the almanac need updating? I regularly use plate solving with my telescope and I've never had to update it's stars database
civvv 13 hours ago [-]
Guess its back to the good ol' map, compass and stopwatch.
19 hours ago [-]
himata4113 20 hours ago [-]
We have starlink I am sure they can figure something out.
mschuster91 20 hours ago [-]
Starlink lacks the high precision atomic clocks on board of the satellites, that is also why Starlink needs a GPS fix to bootstrap itself.
nomel 19 hours ago [-]
Maybe the starlink clocks could continuously calibrate from gps? Clock drift is usually a slow thing (like thermals). Their inter-satellite data links have all sorts of relative clocking info.
KaiserPro 3 hours ago [-]
The orbit accuracy of starlinks are (to me) and unknown. I would suggest that as they are on a lower orbit, they decay much faster.
However, because of the way they communicate node to node, they do need to know where their nearest neighbour is to a very high degree. So relative position is probably easy to obtain.
But if you're gonna do that, you're better off with 4g/5g masts. there are loads of them and they don't generally change position that much. They are clow enough together to do odometry.
Unless youre over the sea.
numpad0 13 hours ago [-]
IIUC, GPS picks one satellite and 3 more to establish time differences between the first one and the other 3. There's only one point in universe where the set of differences would match what was observed, given the broadcast orbital data of satellites, and that gives the location of the receiver. It's like you are provided radii and center coordinates of 3 circles on a paper that intersect at 1 point and you are to math that point.
So GPS-like systems need precise orbital data and coherent clock from each satellites, or otherwise the receiver cannot figure out those radii.
Presumably you can have each sats reflect a clock from the same master ground station but that's not how GPS is implemented currently.
nomel 11 hours ago [-]
Coherency is a state. My question is if that state can be achieved by just tuning the individual clocks/locations based on GPS as a master. And, there's other tricks, with all the inter-satellite communication [1].
And, there's a contextual difference here between civilian GPS and military GPS. Much of the precision in the existing GPS satellites is to support the military use of GPS, with intentionally error injected into the civilian side.
And, by the nature of the hostile environment the military operates, military craft don't have as strong of a reliance on something that's ephemeral, like a GPS signal on a battlefield.
What you describe is very normal in telecom and has been for a long time. 4G, 5G, etc are all totally dependent on every device syncing to the one higher up in the chain. These days typically a digital control loop is used to tune a high frequency voltage-controlled oscillator which feeds a counter. An event (like GPS PPS, or an ethernet frame arriving on the cable) is extracted from the signal and the counter generates a timestamp. The chips to do this are incredibly cheap and the performance is hard to comprehend.
We have starlink I am sure we can figure it out. Like... launch a better GPS system with one rocket?
numpad0 13 hours ago [-]
doesn't take sat swarms. what you need are some cash and bunch of educated and motivated smart people. that can be tricky sometimes
giantg2 2 hours ago [-]
This really shouldn't be a problem. We were lazy with GPS. Maps, compasses, altimeters, etc all still exist. They might not offer the same precision as GPS, but they can easily fill the gaps. We already have inertia guidance systems for munitions. That's pretty accurate and similar in theory.
Descon 12 hours ago [-]
I wish there were cheap Bluetooth jammers to prevent speakers from playing when hiking
elric 9 hours ago [-]
I strongly suspect those would be very illegal and could result in serious side effects, such as for people who use continuous glucose monitors.
stackedinserter 2 hours ago [-]
Even this highly theoretical harm can be avoided if you jam bluetooth with 50% duty cycle. Like, 2s on then 2s off.
nerdsniper 58 minutes ago [-]
Clearly you don’t have a family member who uses CGM’s. They are extremely sensitive to RF disruptions, and often fail for mind bogglingly dumb reasons.
2s on / 2s off would completely disable all of their functionality until the interference was gone. And possibly much longer - they are finicky.
alightsoul 38 minutes ago [-]
This is such a first world problem. The speakers the post refers to are probably in a third world country where no medical equipment uses Bluetooth so jamming it poses no danger.
rc5150 20 minutes ago [-]
surely there's a failsafe if they're that sensitive and finicky.
Counting my lucky stars I don't need one, but if I did, I don't think I'd rely on it if it's that incapable of staying up.
mannanj 54 minutes ago [-]
So they are sensitive to RF but for some reason all the RF around you, from the power lines in the walls, the WIFI, the towers, they are immune to those?
1 hours ago [-]
deadbabe 3 hours ago [-]
Oh wow but a GPS jammer is okay so someone could get lost and possibly killed, or even crash a plane?
bluGill 2 hours ago [-]
Who said a GPS jammer is okay? They are highly illegal in the US and the FCC will hand out large fines when they find one. GPS jammers are cheap though and so it is unlikely the FCC will catch the majority of users.
Though most GPS jamming is by countries at war. Russia has a large GPS jamming operation around Ukraine, and this often affects GPS in other parts of Europe as well. I have no information, but I would be surprised if Iran wasn't also jamming GPS (off and on depending on the current state of their war). You can safely assume every military in the world has some GPS jammers that they have plans to use if it makes sense to them.
trial3 3 hours ago [-]
i’m delighted to report that it’s actually possible for people to talk about a second, related topic in a comment section without invalidating the problems of the main post being commented on
BLEeding is a tool that allows you to jam Bluetooth (BR/EDR) and BLE devices. It can be used to spam DeAuth requests or L2CAP ping requests. It supports Linux, macOS, Windows and Raspberry PI.
ivanjermakov 5 hours ago [-]
Should be easy to purchase a 2.4GHz jammer, about as easy as to get in trouble for using it though.
stackedinserter 2 hours ago [-]
How do you _realistically_ get in trouble for using it? Jam 2.4 at an airport or near military base?
not_a_bot_4sho 33 minutes ago [-]
This guy was caught for jamming cell phones on his commute to "keep people off their phones". I heard of a similar case of someone doing the same on their bus commute but don't have a link for that handy atm
Whenever I hear leaking earbuds on public transport, it's invariably AirPods
12 hours ago [-]
gib444 5 hours ago [-]
Heh yeah the 'oh god 2 minutes with my own thoughts !? Must blare music to stop the pain' or 'look at me, the main character' crowd lol
josefresco 2 hours ago [-]
These takes are unreasonable IMHO. When you pass someone on the trail, even with a BT speaker blasting you hear the music for what.. maybe 15-20 seconds? Is that really ruining your day? Sometimes when I walk or bike with my wife we bring a BT speaker and I can BARELY hear it and I'm walking side-by-side with her getting no more than 15-20 feet away. Let. People. Enjoy. Things.
Edit: Moderated some of my language.
mh- 27 minutes ago [-]
Why not use the even smaller speakers that you put in your ears, and then you can hear it. And it's inaudible to every other human.
FWIW, both Spotify (Jam) and Apple Music (SharePlay) have a feature to sync audio playback and give both participants the ability to control the music from their phone. It was probably targeted at CarPlay/shared speaker situations, but it works great for this.
RunSet 1 hours ago [-]
> Let. People. Enjoy. Things.
Except silence, which is so unnatural that it should be disrupted and criticism of its disruption should be silenced.
dzhiurgis 9 hours ago [-]
Where do you hike where it’s a problem? I mean if I meet perhaps 10 people max over 2 hours. If all of them were blasting music it still wouldn’t worry me at all.
542354234235 3 hours ago [-]
We encountered this on the Inca trail in Peru. All it takes is one rude person.
josefresco 2 hours ago [-]
If passing one person the trail playing audible music ruins your entire experience I'd check on your mental health. Seriously. I too can get mad at ridiculous things (line cutters, rude drivers, loud movie goers) and have to make a conscious effort to stop, take a deep breath and ask myself why I'm letting this innocuous thing effect my day.
davidmurdoch 2 hours ago [-]
Imagine the scenario where you end up hiking within earshot and in the same direction as another group.
speedgoose 1 hours ago [-]
Isn’t it unlikely that both groups share the same hiking speed for a while? And even if you have the same speed, take a break or pass them quickly.
josefresco 2 hours ago [-]
Tip: Take a small break and within 60 seconds you'll be out of earshot. Also, I realize we're not going to agree on this and that's okay.
ssl-3 30 minutes ago [-]
The same thing works for terrible drivers on the road, pushy customers at the supermarket, and all kinds of other bothersome interpersonal situations.
They can be optional. Just grant yourself a moment to let them go away.
Out of sight, out of mind.
kakacik 4 hours ago [-]
Many (surprisingly more reachable ones) parts of European Alps. But very few actually do that, I think they would experience a lot of aggression from others (certainly from me)
mc3301 8 hours ago [-]
Japan.
donohoe 20 hours ago [-]
What I want is a tiny portable bluetooth jammer for those who insist everyone in public must be listening to their music. Sadly they are too clunky to haul around each day.
jcarrano 2 hours ago [-]
It is called "Reggaeton be Gone"[1]. I think the author had too many problems with his neighbor.
If I am not mistaken, this type of jammer can severily affect people with pacemakers. But, as a Brazilian citizen, I can understand the feeling of being forced to listen other's people music.
yjrpnz440v0b2n1 14 hours ago [-]
its myth youre mistaken because that would mean all the wifi devices and normal bt devices will also stop pacemaker. only early version of pacemaker before internet would be affected modern pacemakers have protection as long as you keep a safe 6 inch distance
itake 7 hours ago [-]
can you cite the source?
I'd imagine temporary (15 minutes?) disruption would be considered in the design of pacemakers or blood glucose monitors, but if you're using this in close proximity for a long period of time... then wouldn't there be problems?
alightsoul 35 minutes ago [-]
In a third world country which are the most affected by this, Pacemakers are very rare and if you have one chances are you live in a rich area where you don't live with neighbors who do that. People die before they ever get a chance at having a pacemaker and the very conditions that require it are very rare in those areas in the first place
These "solutions" always seem too broad with too much collateral damage. Would this be doable to do with a directional antenna or something instead, so you could aim at the specific speaker (in your own house) you want silenced?
alightsoul 34 minutes ago [-]
You will need to use your own
abirch 19 hours ago [-]
Unfortunately for me, when I hear music it's from the horrible audio of a cell phone speaker.
subw00f 20 hours ago [-]
Are they? You can make one pretty easily and sew it into your backpack for added camouflage. I heard.
how i even make a clunky one ? need one for a neighbor in 3rd world country with lowest civic sense.
i tried that esp32 that uses nRF24 but it doesnt seem to jam all the time. i heard about hackrf one dont know if its can properly do that.
aidenn0 11 hours ago [-]
You can brute-force jam the entire 80MHz range. However, it would require roughly 13dB more power compared to jamming a narrow-band signal.
In theory, you could try to exploit the adaptive frequency hopping that bluetooth does, nudging it to switch to specific bands, which you will then jam; this could save on energy, but I don't know if anybody's done it.
mlhpdx 20 hours ago [-]
With all the man made EM emitters in the world, it seems like passively matching what can be “seen” to a database of known emitters (with signal profiles and locations) could be extremely accurate where people are (less helpful on the open ocean and remote wilderness). Similar to what’s already being done with Wi-Fi and Bluetooth but general purpose, perhaps?
1718627440 19 hours ago [-]
I think that is already done by the two big smartphone OS vendors.
Terr_ 13 hours ago [-]
They record spots for all wireless access points too, unless you opt-out by naming them certain ways and the surveillance-capitalism company decides to honor it. (e.g. The _nomap suffix.)
I hope some future Wifi standard makes it much easier to anonymize or obscure persistent access points.
Gigachad 11 hours ago [-]
That's always existed with Hidden SSID. If you are particularly paranoid you can set it up like that. But unless you insert personally identifiable info in your wifi name there is not really any privacy risk for this data being mapped.
Terr_ 10 hours ago [-]
> That's always existed with Hidden SSID. If you are particularly paranoid you can set it up like that.
It's actually the opposite, a hidden SSID will backfire and hurt your privacy when it comes to phones and laptops.
With a normal network, your phone can passively listen for when it approaches MyHomeNetwork and then connect. If you change that to a 802.11 hidden SSID, then whenever you aren't connected your phone will be constantly emitting a very distinctive mating-call: "Any hidden networks? Hello, if you're MyHomeNetwork, please then let me in." That makes it easy for someone to uniquely identify your phone as it moves around, and it also takes up more battery power with the often-fruitless transmissions.
Both issues could be reduced by restricting it to only auto-seek the SSID based on other clues, like GPS regions or neighbors' public SSIDs, but that usually isn't a feature.
> But unless you insert personally identifiable info in your wifi name there is not really any privacy risk for this data being mapped.
How often do you reset/rename it? Surely it's at least weird that some big companies, via sensors carried by your neighbors, know you moved your apartments from X to Y even when you don't use any of their products.
Some phone-apps will have access to the network name too, but that seems just marginally worse compared to other identifying info they could track and exfiltrate.
Gigachad 9 hours ago [-]
These are valid points, but I think the utility of being able to get location on your phone without power sucking GPS running all day is greater than the privacy risk of seeing when a wifi AP moved address. Which if you were so inclined, could be avoided by changing the wifi name each move.
noipv4 3 hours ago [-]
Jamming and spoofing have come out of the shadows and into the mainstream. Naive receivers will soon be outclassed by smart receivers.
nutjob2 2 hours ago [-]
This is what I wonder about. Do GPS receivers, aviation class ones, just accept signals coming from whatever location (maybe not from the sky), at whatever strength and reporting whatever location? Also I imagine inertial navigation still works. Using a last "known good" position, can that be used to do a sanity check and too weed out bad actors?
It's like the internet all over again, where adversarial players were just not considered.
bluGill 2 hours ago [-]
It likely is the case that most GPS receives, even aviation class ones just accept signals.
Until a couple years ago this was a theoretical issue that few real world people ever dealt with. Military class GPS likely has some form of protection (but what is classified) since military use of jammers have been known for a few decades - but they were very limited use and so non-militaries just ignored them.
Today things are different. Russia's military is jamming GPS on a large scale and that is affecting areas outside the war zone. GPS jammers are also cheap enough that the FCC and similar organizations (most non-poor countries have one) are unable to keep up with all the illegal uses (most countries have laws predating GPS that make these jammers illegal)
United857 12 hours ago [-]
Aren’t most modern receivers multi-constellation? What is the technical feasibility of jamming every GNSS provider?
tepmoc 9 hours ago [-]
They all within same close tied frequency range, so it’s pretty easy. Though L1,L2,L5 need separate jammers if you only target GNSS
teeray 2 days ago [-]
I saw some rumblings (can't find an article) that there's interest in restarting LORAN to provide an alternative to GPS for this reason.
ianburrell 13 hours ago [-]
eLoran has been proposed as more accurate version of LORAN competitive with GPS.
The Wikipedia page says that China has deployed an eLoran network but I can't tell if used for navigation or just high-precision timing.
geerlingguy 2 hours ago [-]
The US has done tests with eLoran as well. The receivers are quite expensive and the signal isn't permanent yet, so it's more of a lab thing right now. Also experiments with BPS (Broadcast Positioning System) using high power TV transmitters to distribute time and position in urban areas (very hard to overpower that signal).
"In trials conducted by the General Lighthouse Authorities of UK and Ireland, a 1.5W radio jammer was able to knock out GPS signals over a range of 30 kilometers. However, to do the same to the Loran system, you'd need a 40ft tower — and around 25kW of juice to power it."
Well certainly, no one thing is impervious. But if you have GPS, LORAN, VORs, NDBs, astronavigation, etc. you have many more options at your disposal and present a much more complex attack target.
butvacuum 20 hours ago [-]
It's 2026: we have more ways to defeat jamming, or make it irrelevant, at unit costs trivial for commercial and most private applications. 1) atomic clocks can be smaller than a closed fist and allow GPS to work with 3 satalites with ocassional drops to 2. 2) the same clocks can be used to filter out radio sources from the wrong direction. 3) star navigation (commercial is often above weather, most weather is clear in some IR bands) 4) Terain following (easy to store maps now) 5) Inertial. 6) magnetic
When combined it is very hard to break the position fix. I expect the issue with the system is it's a military tech. with all it's that'll associated legal problems. After all. it'd bypass most the protections built into GPS modules.
wbl 20 hours ago [-]
And the military has JDAM with HOJ as a solution for jamming
butvacuum 16 hours ago [-]
I was thinking G-man and a suprise helicopter on your lawn. The government hasn't made a spectical of throwing the book at a jammer recently.
mschuster91 20 hours ago [-]
> astronavigation
Good luck finding a pilot trained on doing this, or an aircraft with high enough window cutouts that allow for the use of a sextant. Old Boeings had them [1], but no modern aircraft does.
I think even among navies you'll be hard pressed to find a navigator who still can do astronavigation. IIRC even the US Navy discontinued astronavigation, but recently-ish reintroduced training for it again.
In the 21st century you don't do astronavigation by hand, you use cameras, computers and software.
Astro-inertial guidance is used for example in submarine-launched ballistic missiles.
"Astro-inertial guidance, or stellar-inertial guidance, is a sensor fusion-information fusion of inertial guidance and celestial navigation. It is usually employed on submarine-launched ballistic missiles. Unlike silo-based intercontinental ballistic missiles, whose launch point does not move and thus can serve as a reference, SLBMs are launched from moving submarines, which complicates the necessary navigational calculations and increases circular error probable. Stellar-inertial guidance is used to correct small position and velocity errors that result from launch condition uncertainties due to errors in the submarine navigation system and errors that may have accumulated in the guidance system during the flight due to imperfect instrument calibration."
Yeah but good luck getting that approved for new airliner designs, much less retrofitting it into existing airliners. For the older ones, you'd probably need to rework half their computers.
bluGill 2 hours ago [-]
Approval in aviation is hard, no argument there. Everybody making a GPS is aware of jamming issues and looking at what their options are. I doubt there is any option that isn't expensive and years out from airplanes. However they are likely to start rolling things out in the next few years just because they need to do something.
Don't forget there is a lot more than aviation. Hikers will want jamming protection if it isn't too expensive (depending on what protection we are talking about it come be cheap or expensive)
teeray 19 hours ago [-]
> Good luck finding a pilot trained on doing this
Not necessary. ICBMs have been able to do this autonomously for a very long time [0]
Not so simple. For one the distances to the transmitter are much smaller, for another the amount of power available to the transmitters is pretty much whatever you want to hook it up to, whereas GPS satellites are on a pretty strict power budget. On the reception side the power levels are many orders of magnitude apart.
cyberax 21 hours ago [-]
Not really. It uses 2MHz band, with the wavelength of around 160m.
This means that it's easy to receive via a ferrite bar antenna but hard to transmit. You need an antenna of at least around 40m size for that to be efficient.
lstodd 20 hours ago [-]
Even a 160m guy-wire tower is cheap. 40m.. my friend installed 32m one just to have better internets, not exactly out of pocket cash, but nothing compared to say swapping a car.
KaiserPro 3 hours ago [-]
yes, but trying to pump 25kw through that without it being obvious is a lot harder.
cyberax 19 hours ago [-]
Sure, but such an antenna will be extremely conspicuous and easy to triangulate. You can't install it covertly.
Meanwhile, GPS can be jammed or spoofed with a briefcase-sized device for a couple of kilometers around you.
laruss5 2 days ago [-]
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rkeswick 12 hours ago [-]
This explains why my drone occasionally loses signal near commercial areas. A real nuisance to deal with.
vamos_davai 6 hours ago [-]
We have a defense budget. Deploy some troops or hellfire the jamming operator
chii 6 hours ago [-]
With each hellfire costing upwards of $150k per shot, it's not cost effective to use them to shoot down jammers
jayshah5696 19 hours ago [-]
This is likely just the start. With growing consumer reliance on GPS, jammer proliferation will mirror what we see in military contexts. Same thing will happen to starlink and jamming in contested zones
seki285 9 minutes ago [-]
You can't jam starlink, at least from what we've seen so far in the war happening in Ukraine.
eternityforest 2 days ago [-]
Is there a reliable app to detect these without using excessive amounts of battery?
thenthenthen 20 hours ago [-]
Better use a software defined radio like hackrf or a more dedicated gps thingy, esp32 with gps addon and some machine learning? (‘Some’ doing a lot of heavy lifting here)
imglorp 21 hours ago [-]
I feel like gps nav software should start considering the jamming and spoofing cases as real conditions they will encounter that should throw up an INOP warning.
It wouldn't take much smarts for it to consider the type of vessel it's in and the max and current speeds. If the calculated position of a 10 knot vessel suddenly jumps 100 km away in seconds, that sure seems like a spoof. And if you had 10 satellites locked and then you have none, that sure seems like jamming, or you're in a tunnel; INOP either way.
stefan_ 21 hours ago [-]
The systems jamming in Hormuz and Ukraine aren't exactly cheap and low powered, nor are those used by the US military in one of their many jamming exercises every year. Cheap GPS jammers fit in a cigarette lighter and are used by truckers who don't want their boss snooping on them, but they don't quite threaten aviation.
That aside, you don't need to give up on GPS just yet. As expensive as airplanes are, there is no reason not to have at least 8 element CRPA receivers in them. Mostly a military niche product in the past they are rapidly proliferating, and most fuselages make for a great ground plane.
bigfatkitten 13 hours ago [-]
> Cheap GPS jammers fit in a cigarette lighter and are used by truckers who don't want their boss snooping on them, but they don't quite threaten aviation.
They absolutely do threaten air and maritime navigation, because those trucks drive in and near ports and airports.
Starlink can be uses as GPS. Good luck jamming 20 thousand satellites.
left-struck 12 hours ago [-]
First of all, starlink has been jammed in conflict zones.
Secondly, the number of satellites doesn’t really matter, the jamming happens at the end user level not at the satellite.
Finally, where are you getting that 20k number from? It’s not like there’s 20k starlink satellites in LOS to your station at all times. The earth will be obscuring many of those, they are below your feet on the other side of the planet.
dghlsakjg 14 hours ago [-]
Do they have atomic clocks on board?
I was under the impression that Starlink needs GPS for initial acquisition.
bluGill 2 hours ago [-]
They don't need atomic clocks on board. NTP is close enough for most purposes. Sure your error goes up, but often within 100 meters is good enough. The exceptions though do need accurate clocks and are a problem.
nomel 19 hours ago [-]
That's near orders of magnitude more than reality. The only number that matters is the number of satellites that are in communication line of site. A satellite on the other side of the world doesn't help you.
m463 14 hours ago [-]
I wonder how many are in view?
gps is 31 total satellites 12,000 miles up
starlink is 10,000 satellites at ~ 300 miles. (and what orbit?)
EDIT: I found this:
-- starlink:
"In any given place there are 3-4 Starlink satellites visible at a time"
You also need to know where the satellites are meant to be at any one time. That means a stable orbit. Starlink isn't really designed for that.
It then also needs to be signed/secure so that its not spoofed.
Then your signal that your measuring time from needs to be transmitted often enough and robust enough. Plus your time source on the transmitter needs to be accurate enough.
It might be possible with starlink, but you'd also have to trust musk....
BenjiWiebe 12 hours ago [-]
Remember there's also BeiDou, Galileo, and GLONASS as well.
Our RTK base station (a Ublox ZED-F9P receiver, with a cheap patch antenna on the roof) can currently see 45 GNSS satellites.
inemesitaffia 20 hours ago [-]
They've removed the in-built PNT service
juliusceasar 2 days ago [-]
Those cheap GPS jammers, which sites should I avoid to not buy them by accident?
vablings 20 hours ago [-]
It's not rocket science to make a GPS jammer. GPS Spoofing is more complex and causes way more damage or chaos. I would seriously avoid touching this subject whatsoever this is the kind of thing that will have the FBI and FCC so far up your ass you will feel it in the back of your eyeballs. On the off chance the feds don't catch you and you cause a serious accident you will be charged with 1st degree murder of how many people were on the aircraft that crashed along with a litany of other federal offences meaning life without parole is basically a guarantee.
michaelmrose 21 hours ago [-]
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djoldman 21 hours ago [-]
No worries in the long run; similar to the "energy crisis," new inventions and technology will mitigate the issue:
The magnetic approach is very interesting. I can't imagine it would ever be reliable enough for a primary instrument since its susceptible to solar weather and certain regions with more geological activity.
Hizonner 21 hours ago [-]
I'm sorry, but a multi-kilogram (at a guess), five-figure-priced (at a conservative guess) device with kilometer-scale error (per their actual press release) is not a substitute for a GPS.
And you probably can't improve on many of those specs no matter how much "inventing" you do. There's just not that much information in magnetic fields, especially if you don't spend an infeasible amount of money on keeping maps up to date. You're probably jammable, too.
The same applies to the gravitational hacks, and the mapping issue applies even to visual navigation.
Those guesses, by the way, are because not only is AQNav's "data sheet" worthless fluff, but they seem to be allergic to letting anybody even see a picture of the product. Which makes me doubt that they actually have what a normal person would think of as a "product" to begin with.
monster_truck 11 hours ago [-]
Datasheets that look like that are a pretty strong indicator you're dealing with something that is giga export controlled, not as in "can only go to some countries, you have to declare it and theres a LOT of paperwork", more "attempting to, or even making plans about trying to leave the country with one is a pile of federal crimes"
Virtually anything navigational that cannot be easily or reliably jammed falls into this category far before meeting any of the accuracy/drift requirements.
Hizonner 1 hours ago [-]
Seems kind of contrary to the point of a navigation device...
djoldman 19 hours ago [-]
No need to be sorry.
My "no worries" comment was a bit tongue-in-cheek. Who knows how far the tech will go or how cheap it will get.
GPS is fantastic and as a primary source everyone loves the benefits it brings. However, in a century of aviation, everyone has kinda sorted out that you can't have too many backups to critical items... unless you let the accountants and bureaucrats run the show.
In the '90s I used to fly light aircraft back and forth between Seattle and Alaska. You were frequently out of range of any VOR transmitters, but that LORAN always worked. NDBs? That didn't work so great for Ron Brown.
https://en.wikipedia.org/wiki/Loran-C
However, in a modern commercial aircraft, all position sources including VOR-DMEs, GPS, and IRS are cross-compared by the flight management system and turned into a latitude, longitude, and circular error of probability. There is no TO/FROM flag to worry about in a 777, and no reverse sensing on the back side of a localizer approach.
It's really hard to jam oceanic areas though, you need a vessel capable of sustaining human life autonomously at least for days plus dealing with the high seas.
Buoys could theoretically be used for that purpose, yes, but good luck getting them stationary enough. Maybe some of the secret services could pull off such a trick but at least no ordinary civilian.
Not really. Drone ships are very much a thing these days.
But in theory you're not wrong.
Depending on their kind they might not return a specific position, but in combination with other sources they often do via triangulation.
PS: INS (Inertial Navigation) also still exits. It often works for quite a long time really precisely. Also precision can be calculated. So it can start as a dot on a map which becomes a bigger circle as the precision decreases. It could be automatically recalibrated whenever high confidence positioning is available.
Essentially a position is calculated from VOR/DME, GPS, and INS. When there is disagreement it is flagged and procedures are in place to fall back.
The issue is VOR/DME is slowly being decommissioned eliminating one of those sanity checks. It hasn't been degraded to the point of creating massive gaps in coverage over land but it will slowly happen if the rate of decommissioning continues.
Ultimately, INS is sufficient for enroute navigation but if you're degraded to just that state, the impacts to traffic separation, particularly in congested airspace, are significant. Required Navigation Performance (RNP) levels dictate all of this.
https://en.wikipedia.org/wiki/Decca_Navigator_System
Yes, we can stop that with modern tech, but the problem with loran-c is you had location ambiguities. Decca was worse, unless you had a good initial fix, you were all sorts of fucked. There are of course modern alternatives, but they are not block proof, or turned on.
There is a very good reason why GPS was opened up, because the alternatives were not anywhere near as good.
Now, what are the alternatives? well hyperbolic navigation is still a thing, and with modern electronics you can get a pretty good fix without any of the nasty ambiguaty that loran-c had. If you are flying over land, then visual odometry is now at a point where you can locate pretty accurately autonomously (assuming cloud cover is your firend)
Small low power ceasium clocks are $4k now, and only really need a few hundred millitwatts to run, which opens up a whole load of other ways to navigate.
then there are IMUs, they are dirt cheap and way more accurate than 20 years ago. A calibrated array should be able to sustain reasonable accuracy after 30 minutes now
https://en.wikipedia.org/wiki/Transcontinental_Airway_System
and have giant concrete QR codes
As more and more are decommissioned, the percentage that support distance-measuring goes up, as the ones being decommissioned are more likely to be the less-useful ones, which are less likely to have supported DME in the first place. So most remaining ones support both, but it’s not assured without checking.
More common is to use Nav2 tuned to a VOR to find an intersection on the arrival and Nav 1 to fly the final (ILS/LOC/VOR).
There's GPS jamming by the military, mostly in war zones. This seldom effects airliners because they steer clear of active war zones.
Then there's GPS jamming by delivery drivers who don't want their boss watching over their shoulder all the time. When the article mentions jammers as small as a cellphone and costing less than $100, those are sold to drivers.
Delivery drivers don't jam LORAN or VOR, though - so it's not jammed by the second type.
The plane reported GPS signal loss 5 minutes after the jamming started by WSMR. Three other planes in the area also reported GPS loss.
https://www.stripes.com/theaters/us/2026-08-05/ntsb-medevac-...
That one’s going to be on the flight crew, not the GPS jamming test.
HN discussion: https://news.ycombinator.com/item?id=49181099
One is to actually jam the signal IOW preventing reception. The other is to overpower the satellites' signals and replace them with your own. That defeats the doppler calculations of GPS needed for triangulation, and instead the receiver believes it's where the jammer wants it to be.
If the latter includes altitude information, then it's a huge problem.
If you can say, "oh we were only jamming" when in fact you were spoofing, well that's certainly a super easy excuse to hide behind.
Yes, obviously. Losing signal on your GPS unit, and having your GPS unit tell you that you are in a different position than you actually are, are two very different things.
Also, since other aircraft reported GPS issues, that is evidence that would speak to jamming or spoofing. All three other aircraft reported a loss of GPS, not inaccurate GPS. Coverups are real, government conspiracies are real. But the completely evidenceless “I’m just saying…” or “isn’t it weird…” or “I’m just asking questions” is tiresome.
Sounds like the root cause to me. It should be illegal to use GNSS to track employees, or anyone really.
Jamming is starting to sound a lot like self-defense against surveillance.
The real problem is not really drivers being tracked, but how the tracking data is or might be used. Timestamped delivery notifications might be just as bad in this regard.
As often, the solution is probably more about accessible and pro-human law. No idea how that should work, maybe certain sensitive data services having to be provided by a third party or even the government itself? There are probably much smarter ideas or variations of this...
These antennas have a very good idea of where the signal is coming from, due to delay measurements and can detect and filter ambient noise. They are super hard to jam. The reason why drones have become such a PITA is that these inexpensive antennas are very hard to defeat even with military jammers.
If this becomes a geniune need in the civilian sector, then I'm sure the tech is up to the challenge.
Brad Parkinson, the father of GPS and PNTAB, they've been trying to lobby the US government to remove ITAR from that technology so the civilian can benefit from anti jamming, and finally they managed to do it sometime last year. Now it falls under EAR
Not sure what makes an antenna/sensor ITAR restricted, I suspect if you try optimizing it to military use-cases, you'll get hit with ITAR, but I suspect Brad Parkinson is right - security through obscurity just doesn't cut it any more.
I remember in the 90s, computer security was either missing or an afterthought (you could bypass the Win98 password prompt by pressing escape in the release version). Thankfully the industry got together and figured it out.
Now everyone else needs to follow suit. We already have a bunch of examples of assuming security does not matter (hackable cars, meters that can be switched with a Flipper zero).
Similar things already exist - although it's used for increasing GPS precision and detecting faulty satellites, moreso than detecting jamming, so the networks might not be dense enough to detect small areas of jamming.
For one state's example, see [1] - choose 'RINEX archives' if you want historical readings.
[1] http://www.wsrn.org/Map/SensorMap.aspx
The police could probably combine this data with license plate scanners and see the single truck that always exists in the jammed location.
Yeah the FCC could probably pull an ATF and shoot a bunch of people over fairly petty crimes but that costs political goodwill that I'm not sure the FCC has to burn.
https://www.fcc.gov/enforcement/orders you can just look at the enforcement actions.
Yesterday's actions include 7 $25k fines apparently all for companies illegally importing banned drones (a procedural fine just for ignoring the investigation attempts). You can peruse that list and find plenty of things, lots of pirate radio recently. They absolutely do go after apparent small fry and your "mcdonalds manager" absolutely has assets that can be seized.
>Yeah the FCC could probably pull an ATF and shoot a bunch of people over fairly petty crimes but that costs political goodwill that I'm not sure the FCC has to burn.
The FCC doesn't have guns, they can't arrest you
Btw, don't smartphones have this built in? I remember some old and cheap Android phones without GPS that came with this.
Received GNSS power is on the order of -130dBm (10e-16 W) - you can jam that with a 1W terrestrial source for hundreds of meters around. Way more if you're willing to scale the power from car USB power levels to bigger grid-connected supplies.
LORAN, from my quick googling, looks to be about 6-7 orders of magnitude higher received power.
Although that approach depends on you being able to see the ground neither of which is guaranteed over a body of water or in poor visibility.
I have recently heard an episode of Amp Hour podcast¹ where they talked about using Bluetooth from satellites as a GPS replacement for asset tags. So maybe alternatives to GPS on different bands are on the verge.
Another interesting idea would be to have an antenna array on the plane that captures different radio sources and the angles from which they seem to come from and create a always updating radio activity map that maps a certain "radio landscape" to a position on the planet. AFAIK this is currently being worked on as well under the name "radio-SLAM" (with SLAM standing for Simultaneous Localization and Mapping). This means, jammers could maybe even be used as potential beacons themselves.
¹: The episode in question: https://theamphour.com/728-space-age-bluetooth-with-alex-har...
GPS signals are just incredibly weak so it takes next to nothing to drown them out, easier still if you are above the receiver.
https://news.ycombinator.com/item?id=49186101
https://news.ycombinator.com/item?id=49184484
GPSJam: Daily maps of possible GPS interference - https://news.ycombinator.com/item?id=37868106 - October 2023 (89 comments)
GPSJam: Daily Maps of GPS Interference - https://news.ycombinator.com/item?id=32245346 - July 2022 (82 comments)
https://en.wikipedia.org/wiki/Transmitter_hunting | https://en.wikipedia.org/wiki/Pseudo-range_multilateration | https://www.arrl.org/direction-finding
https://geodesy.noaa.gov/CORS/ | https://arcg.is/18fWq8
GPS was jammed even as early as Iraq war.
"Coalition troops also got a glimpse of GPS’s greatest weakness during the Gulf War. Iraqi forces installed jammers, for example, on top of landmarks such as Saddam Hussein’s palaces to prevent them from being hit, Mastalir says. This helped the military realize early on that it would have to further develop its laser-guided munitions and other weapons that acquire targets when GPS is unavailable"
https://web.archive.org/web/20160208233555/http://www.scient...
What work is done to make GPS more jam resistant?
https://insidegnss.com/onenav-l5-direct-technology-enables-d...
For obvious reasons hard information about all this is tricky to come by, you can read what is available from non-classified sources though and you can glean quite a bit from there.
https://en.wikipedia.org/wiki/GPS_signals#L5
The third edition of 'Kaplan' is still excellent reading on the subject even though it is 10 years old now.
Impressive performance.
Single element antennas, adaptive antennas, beam steering antennas. Basically attempting to pull good RF while avoiding bad RF.
(this has been applied in the Russo-Ukrainian war in modified Starlink equipment)
GPS antenna mods make Starlink terminal immune to jammers - https://news.ycombinator.com/item?id=39616417 - March 2024 (72 comments)
https://olegkutkov.me/2023/11/07/connecting-external-gps-ant...
https://www.gpsworld.com/todd-humphreys-russian-satellites-a...
Ongoing Ukrainian strikes against Rassvet satellite production and launch sites contribute to further impairment of Russia's ability to get any new or replacement satellites to orbit.
https://ua.news/en/war-vs-rf/video-ukrayina-atakuvala-golovn...
https://en.wikipedia.org/wiki/Kosmos_2446
https://arxiv.org/html/2606.03673v1
https://www.youtube.com/watch?v=cRiOkQ1ngAM
With a quick calculation 50 ms time offset would mean about 20 meter difference. You can get that accuracy with NTP over residential internet and a better TCXO could hold that for a day. You could sync clocks and download the almanac at each airport. The almanac could be digitally signed and NTP has an option for authentication, too. That's about 10 USD of hardware (plus what you need for image capture and processing).
I'm pretty sure with dedicated hardware and better solutions you could get much better accuracy.
[0] https://www.righto.com/2026/04/B-52-star-tracker-angle-compu...
However, because of the way they communicate node to node, they do need to know where their nearest neighbour is to a very high degree. So relative position is probably easy to obtain.
But if you're gonna do that, you're better off with 4g/5g masts. there are loads of them and they don't generally change position that much. They are clow enough together to do odometry.
Unless youre over the sea.
So GPS-like systems need precise orbital data and coherent clock from each satellites, or otherwise the receiver cannot figure out those radii.
Presumably you can have each sats reflect a clock from the same master ground station but that's not how GPS is implemented currently.
And, there's a contextual difference here between civilian GPS and military GPS. Much of the precision in the existing GPS satellites is to support the military use of GPS, with intentionally error injected into the civilian side.
And, by the nature of the hostile environment the military operates, military craft don't have as strong of a reliance on something that's ephemeral, like a GPS signal on a battlefield.
[1] https://arxiv.org/pdf/2501.05302
https://www.ti.com/product-category/clocks-timing/clock-netw...
2s on / 2s off would completely disable all of their functionality until the interference was gone. And possibly much longer - they are finicky.
Counting my lucky stars I don't need one, but if I did, I don't think I'd rely on it if it's that incapable of staying up.
Though most GPS jamming is by countries at war. Russia has a large GPS jamming operation around Ukraine, and this often affects GPS in other parts of Europe as well. I have no information, but I would be surprised if Iran wasn't also jamming GPS (off and on depending on the current state of their war). You can safely assume every military in the world has some GPS jammers that they have plans to use if it makes sense to them.
BLEeding is a tool that allows you to jam Bluetooth (BR/EDR) and BLE devices. It can be used to spam DeAuth requests or L2CAP ping requests. It supports Linux, macOS, Windows and Raspberry PI.
https://www.pcmag.com/news/fla-man-fined-48k-for-jamming-cel...
Edit: Moderated some of my language.
FWIW, both Spotify (Jam) and Apple Music (SharePlay) have a feature to sync audio playback and give both participants the ability to control the music from their phone. It was probably targeted at CarPlay/shared speaker situations, but it works great for this.
Except silence, which is so unnatural that it should be disrupted and criticism of its disruption should be silenced.
They can be optional. Just grant yourself a moment to let them go away.
Out of sight, out of mind.
[1] https://github.com/ronibandini/reggaetonBeGone
I'd imagine temporary (15 minutes?) disruption would be considered in the design of pacemakers or blood glucose monitors, but if you're using this in close proximity for a long period of time... then wouldn't there be problems?
https://github.com/cifertech/RF-Clown
You can use their files to make one via a pcb vendor like jlpcb or you can look for someone who has already done that:
https://www.tindie.com/products/ryanyu/rf-clown-v20-esp32-wi...
i tried that esp32 that uses nRF24 but it doesnt seem to jam all the time. i heard about hackrf one dont know if its can properly do that.
In theory, you could try to exploit the adaptive frequency hopping that bluetooth does, nudging it to switch to specific bands, which you will then jam; this could save on energy, but I don't know if anybody's done it.
I hope some future Wifi standard makes it much easier to anonymize or obscure persistent access points.
It's actually the opposite, a hidden SSID will backfire and hurt your privacy when it comes to phones and laptops.
With a normal network, your phone can passively listen for when it approaches MyHomeNetwork and then connect. If you change that to a 802.11 hidden SSID, then whenever you aren't connected your phone will be constantly emitting a very distinctive mating-call: "Any hidden networks? Hello, if you're MyHomeNetwork, please then let me in." That makes it easy for someone to uniquely identify your phone as it moves around, and it also takes up more battery power with the often-fruitless transmissions.
Both issues could be reduced by restricting it to only auto-seek the SSID based on other clues, like GPS regions or neighbors' public SSIDs, but that usually isn't a feature.
> But unless you insert personally identifiable info in your wifi name there is not really any privacy risk for this data being mapped.
How often do you reset/rename it? Surely it's at least weird that some big companies, via sensors carried by your neighbors, know you moved your apartments from X to Y even when you don't use any of their products.
Some phone-apps will have access to the network name too, but that seems just marginally worse compared to other identifying info they could track and exfiltrate.
It's like the internet all over again, where adversarial players were just not considered.
Until a couple years ago this was a theoretical issue that few real world people ever dealt with. Military class GPS likely has some form of protection (but what is classified) since military use of jammers have been known for a few decades - but they were very limited use and so non-militaries just ignored them.
Today things are different. Russia's military is jamming GPS on a large scale and that is affecting areas outside the war zone. GPS jammers are also cheap enough that the FCC and similar organizations (most non-poor countries have one) are unable to keep up with all the illegal uses (most countries have laws predating GPS that make these jammers illegal)
The Wikipedia page says that China has deployed an eLoran network but I can't tell if used for navigation or just high-precision timing.
* https://insidegnss.com/uk-and-france-renew-ties-resilient-pn...
https://www.engadget.com/2013-01-21-uk-eloran-navigation-sys...
When combined it is very hard to break the position fix. I expect the issue with the system is it's a military tech. with all it's that'll associated legal problems. After all. it'd bypass most the protections built into GPS modules.
Good luck finding a pilot trained on doing this, or an aircraft with high enough window cutouts that allow for the use of a sextant. Old Boeings had them [1], but no modern aircraft does.
I think even among navies you'll be hard pressed to find a navigator who still can do astronavigation. IIRC even the US Navy discontinued astronavigation, but recently-ish reintroduced training for it again.
[1] https://virginflightdeck.blogspot.com/2010_09_01_archive.htm...
Astro-inertial guidance is used for example in submarine-launched ballistic missiles.
"Astro-inertial guidance, or stellar-inertial guidance, is a sensor fusion-information fusion of inertial guidance and celestial navigation. It is usually employed on submarine-launched ballistic missiles. Unlike silo-based intercontinental ballistic missiles, whose launch point does not move and thus can serve as a reference, SLBMs are launched from moving submarines, which complicates the necessary navigational calculations and increases circular error probable. Stellar-inertial guidance is used to correct small position and velocity errors that result from launch condition uncertainties due to errors in the submarine navigation system and errors that may have accumulated in the guidance system during the flight due to imperfect instrument calibration."
https://en.wikipedia.org/wiki/Missile_guidance
Don't forget there is a lot more than aviation. Hikers will want jamming protection if it isn't too expensive (depending on what protection we are talking about it come be cheap or expensive)
Not necessary. ICBMs have been able to do this autonomously for a very long time [0]
[0] https://en.wikipedia.org/wiki/Celestial_navigation
This means that it's easy to receive via a ferrite bar antenna but hard to transmit. You need an antenna of at least around 40m size for that to be efficient.
Meanwhile, GPS can be jammed or spoofed with a briefcase-sized device for a couple of kilometers around you.
It wouldn't take much smarts for it to consider the type of vessel it's in and the max and current speeds. If the calculated position of a 10 knot vessel suddenly jumps 100 km away in seconds, that sure seems like a spoof. And if you had 10 satellites locked and then you have none, that sure seems like jamming, or you're in a tunnel; INOP either way.
That aside, you don't need to give up on GPS just yet. As expensive as airplanes are, there is no reason not to have at least 8 element CRPA receivers in them. Mostly a military niche product in the past they are rapidly proliferating, and most fuselages make for a great ground plane.
They absolutely do threaten air and maritime navigation, because those trucks drive in and near ports and airports.
https://insidegnss.com/fcc-fines-operator-of-gps-jammer-that...
https://ilwulocal94.org/news/2024/CSA%2001-24%20GPS%20Jammin...
This was an interesting article up to the point where the writer started taking SandboxAQ seriously.
For why you shouldn't take SandboxAQ seriously as a creator of actual technology or real products, start here: https://www.theinformation.com/articles/lavish-spending-weak...
Secondly, the number of satellites doesn’t really matter, the jamming happens at the end user level not at the satellite.
Finally, where are you getting that 20k number from? It’s not like there’s 20k starlink satellites in LOS to your station at all times. The earth will be obscuring many of those, they are below your feet on the other side of the planet.
I was under the impression that Starlink needs GPS for initial acquisition.
gps is 31 total satellites 12,000 miles up
starlink is 10,000 satellites at ~ 300 miles. (and what orbit?)
EDIT: I found this:
-- starlink:
"In any given place there are 3-4 Starlink satellites visible at a time"
https://news.ycombinator.com/item?id=42445512 :)
in december 2024, there were 4,000 starlink satellites in orbit
so starlink is ~ 8 at all times?
-- GPS:
This 24-slot arrangement ensures users can view at least four satellites from virtually any point on the planet.
- https://www.gps.gov/space-segment
It then also needs to be signed/secure so that its not spoofed.
Then your signal that your measuring time from needs to be transmitted often enough and robust enough. Plus your time source on the transmitter needs to be accurate enough.
It might be possible with starlink, but you'd also have to trust musk....
Our RTK base station (a Ublox ZED-F9P receiver, with a cheap patch antenna on the roof) can currently see 45 GNSS satellites.
Quantum Compass: https://en.wikipedia.org/wiki/Quantum_compass
Also see: https://www.sandboxaq.com/post/sandboxaq-and-acubed-achieve-...
And you probably can't improve on many of those specs no matter how much "inventing" you do. There's just not that much information in magnetic fields, especially if you don't spend an infeasible amount of money on keeping maps up to date. You're probably jammable, too.
The same applies to the gravitational hacks, and the mapping issue applies even to visual navigation.
Those guesses, by the way, are because not only is AQNav's "data sheet" worthless fluff, but they seem to be allergic to letting anybody even see a picture of the product. Which makes me doubt that they actually have what a normal person would think of as a "product" to begin with.
Virtually anything navigational that cannot be easily or reliably jammed falls into this category far before meeting any of the accuracy/drift requirements.
My "no worries" comment was a bit tongue-in-cheek. Who knows how far the tech will go or how cheap it will get.