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.<p>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.
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.<p>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.<p><a href="https://en.wikipedia.org/wiki/Loran-C" rel="nofollow">https://en.wikipedia.org/wiki/Loran-C</a>
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.
If you are a general aviation goober like me, flying a 1960's propeller airplane, sure, that is true.<p>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.
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.
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.
> Additionally it cannot provide coverage over oceanic areas.<p>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.<p>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.
Most pre-GPS navigation systems have shorter baselines than GPS and therefore accuracy is much worse, on top of generally being more complicated
maybe we need to update those giant concrete arrows on the ground...<p><a href="https://en.wikipedia.org/wiki/Transcontinental_Airway_System" rel="nofollow">https://en.wikipedia.org/wiki/Transcontinental_Airway_System</a><p>and have giant concrete QR codes
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?
There are two types of GPS jamming.<p>There's GPS jamming by the military, mostly in war zones. This seldom effects airliners because they steer clear of active war zones.<p>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.<p>Delivery drivers don't jam LORAN or VOR, though - so it's not jammed by the second type.
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 <i>much</i> higher powers.<p>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.<p>LORAN, from my quick googling, looks to be about 6-7 orders of magnitude higher received power.
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.
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.<p>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.
And LORAN. But it may make a come-back.<p>GPS signals are just incredibly weak so it takes next to nothing to drown them out, easier still if you are above the receiver.
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).<p><a href="https://news.ycombinator.com/item?id=49186101">https://news.ycombinator.com/item?id=49186101</a><p><a href="https://news.ycombinator.com/item?id=49184484">https://news.ycombinator.com/item?id=49184484</a><p><i>GPSJam: Daily maps of possible GPS interference</i> - <a href="https://news.ycombinator.com/item?id=37868106">https://news.ycombinator.com/item?id=37868106</a> - October 2023 (89 comments)<p><i>GPSJam: Daily Maps of GPS Interference</i> - <a href="https://news.ycombinator.com/item?id=32245346">https://news.ycombinator.com/item?id=32245346</a> - July 2022 (82 comments)<p><a href="https://en.wikipedia.org/wiki/Transmitter_hunting" rel="nofollow">https://en.wikipedia.org/wiki/Transmitter_hunting</a> | <a href="https://en.wikipedia.org/wiki/Pseudo-range_multilateration" rel="nofollow">https://en.wikipedia.org/wiki/Pseudo-range_multilateration</a> | <a href="https://www.arrl.org/direction-finding" rel="nofollow">https://www.arrl.org/direction-finding</a><p><a href="https://geodesy.noaa.gov/CORS/" rel="nofollow">https://geodesy.noaa.gov/CORS/</a> | <a href="https://arcg.is/18fWq8" rel="nofollow">https://arcg.is/18fWq8</a>
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).<p>GPS was jammed even as early as Iraq war.<p>"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"<p><a href="https://web.archive.org/web/20160208233555/http://www.scientificamerican.com/article/gps-and-the-world-s-first-space-war/" rel="nofollow">https://web.archive.org/web/20160208233555/http://www.scient...</a>
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.
We have starlink I am sure they can figure something out.
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.
<a href="https://stfu.pankajtanwar.in/" rel="nofollow">https://stfu.pankajtanwar.in/</a>
how i even make a clunky one ? need one for a neighbor in 3rd world country with lowest civic sense.<p>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.
Unfortunately for me, when I hear music it's from the horrible audio of a cell phone speaker.
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.
Are they? You can make one pretty easily and sew it into your backpack for added camouflage. I heard.
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?
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.
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
> At the quantum-sensing firm SandboxAQ, an Alphabet spinoff…<p>This was an interesting article up to the point where the writer started taking SandboxAQ seriously.<p>For why you shouldn't take SandboxAQ seriously as a creator of actual technology or real products, start here:
<a href="https://www.theinformation.com/articles/lavish-spending-weak-growth-engulf-billionaire-backed-ai-startup-sandboxaq" rel="nofollow">https://www.theinformation.com/articles/lavish-spending-weak...</a>
Is there a reliable app to detect these without using excessive amounts of battery?
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)
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.<p>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.
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.<p>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.
Starlink can be uses as GPS. Good luck jamming 20 thousand satellites.
Do they have atomic clocks on board?<p>I was under the impression that Starlink needs GPS for initial acquisition.
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.
I wonder how many are in view?<p>gps is 31 total satellites 12,000 miles up<p>starlink is 10,000 satellites at ~ 300 miles. (and what orbit?)<p>EDIT: I found this:<p>-- starlink:<p>"In any given place there are 3-4 Starlink satellites visible at a time"<p><a href="https://news.ycombinator.com/item?id=42445512">https://news.ycombinator.com/item?id=42445512</a> :)<p>in december 2024, there were 4,000 starlink satellites in orbit<p>so starlink is ~ 8 at all times?<p>-- GPS:<p><i>This 24-slot arrangement ensures users can view at least four satellites from virtually any point on the planet.</i><p>- <a href="https://www.gps.gov/space-segment" rel="nofollow">https://www.gps.gov/space-segment</a>
They've removed the in-built PNT service
<a href="https://archive.is/zUA3D" rel="nofollow">https://archive.is/zUA3D</a>
Those cheap GPS jammers, which sites should I avoid to not buy them by accident?
No worries in the long run; similar to the "energy crisis," new inventions and technology will mitigate the issue:<p>Quantum Compass: <a href="https://en.wikipedia.org/wiki/Quantum_compass" rel="nofollow">https://en.wikipedia.org/wiki/Quantum_compass</a><p>Also see: <a href="https://www.sandboxaq.com/post/sandboxaq-and-acubed-achieve-remarkable-progress-in-magnetic-navigation" rel="nofollow">https://www.sandboxaq.com/post/sandboxaq-and-acubed-achieve-...</a>
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.
Also see
<a href="https://q-ctrl.com/ironstone-opal" rel="nofollow">https://q-ctrl.com/ironstone-opal</a>
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.<p>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.<p>The same applies to the gravitational hacks, and the mapping issue applies even to visual navigation.<p>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.