> "Aircraft are greatly affected by the GPS jamming and it's not taken seriously by management," reads one report. "We've been told we can't ask to stop jamming, and to just put everyone on headings."
This is the military practicing, but I would hope that civilian airline transport operations are also robust to GNSS unavailability or denial. Even private pilots in little Cessnas are taught to navigate using radio-navigation (NDB beacons, VORs, etc.) in the event that GPS is not available. You should absolutely be able to turn your GPS off and get to your destination.
The fact that radio-navigation aids are being phased out in favor of GNSS, turning it into a single point of failure, is pretty concerning.
It's not so much that you can't fly from VOR to VOR, everyone knows how to do so. It's more that it's a horrible waste of time and fuel.
If you have GPS, you will get cleared direct after getting out of congested areas, usually (presuming you are capable of clearing all of the terrain between point A and point B). If you're having to fly from VOR to VOR you will fly a much more indirect route and spend a lot more time and fuel, particularly on private jets.
Hence the offer to put private jets on vectors rather than tell them to fly the old fashioned way. People on private jets tend to be people who make political contributions, who in turn tend to call the congressmen in their pocket and complain.
There's an incredible amount of inefficiency in the airspace system that causes massive fuel and time waste, but flying VOR to VOR in cruise doesn't seem like one of them. Airline routes are still frequently planned along airways with lots of VOR to VOR along the way. Yes, you get directs, but these only save a minute or two. If you're in a Gulfstream flying above everyone else, sure, it's "direct Van Nuys" from over NYC. Airlines don't get that treatment though.
>> a single point of failure, is pretty concerning.
If is it concerning, we must have a definition of "failure". Does failure mean the inability to fly a route as planned? If so then we cannot fly any routes via GPS that we cannot fly without GPS. So GPS doesn't really add any efficiencies. But if we instead define failure as "danger to life" then we can accept that when GPS fails we will use the other systems to get aircraft to a safe landing, even if flights don't complete as planned. Under that definition we can still enjoy the efficiencies of GPS without maintaining a backup that can instantly replace all GPS functions.
This is very important in a military context too. If you always need a 100% backup at the ready then you cannot ever use a novel system. Any new system won't have a backup that is 100% equal. So to leverage new tech you must accept the risk that you may loose some abilities should it fail. If you won't use the new toy until it has a 100% backup, you will end up never playing with any new toys/weapons.
Bad idea. Relying on any single technology creates a nasty single point of failure. GPS signals are weak signals from satellites & obviously can be jammed.
The VOR MON is structured to provide a usable (for safety purposes) backstop should GPS fail, so from a safety perspective this isn’t making us more reliant.
Are they still taught to do NDB approaches? I thought that's been phased out, too. In fact I was told the other day that the US officially tuned off the NDBs? Does not apply to VORs then, but as you say, the fact that they get phased out more and more is concerning.
Most VORs are being phased out as well, with only a minimum network left in place to support routing flights on instrument flight plans to airports with non-GPS approaches (i.e., ILS) in the event of a GPS outage.
There are no more usable NDBs in/around most bravo cities. The last one in DFW was decommissioned about 3 years ago. Any other ones that are still functional are on borrowed time.
Furthermore, no one is making the receivers anymore. If you have an NDB needle in the panel you are flying an airplane with some awfully old gauges....
Most US pilots could not fly an NDB approach using a simple ADF today, and would end up dead in mountainous terrain.
The reason is that you have to practise doing relative bearings and wind corrections in your head, or else you fly in a spiral towards the station (unlike VOR, which displays absolute radials.) That means you will be off the protected approach path, and can hit obstacles.
If they could fly an ADF, then AM radio stations can be used if necessary. (Airlines used to pay local radio stations to do a station identification announcement upon a phone call from ops, with the radio station typically near a coastline.)
Just don't hit the radio station antenna!
Note that NDB and VOR approaches are non-precision, which means they have lateral guidance but not vertical. So with low clouds, you won't get descent info to the runway like ILS.
That's a big deal for airlines, since they have company operations minimums that may not even allow NDB approaches, which are more restrictive than standard Part 91 (GA) operations minimums. For example, there are situations where I can takeoff in a Cessna with 0/0, that airlines can't.
Great discussion forum on navigating using radio stations:
What I don't understand is how this is supposed to work when the point of using the more precise GPS-based ADS-B positional reporting is for controllers to be able to pack airplanes closer together. If they do this, there will literally not be space in the sky to spread out existing air traffic to radar-based separation requirements.
Why is the FAA transitioning away from radar and towards ADS-B technology? ... The improved accuracy, integrity and reliability of satellite signals over radar means controllers will be able to safely reduce the minimum separation distance between aircraft and increase capacity in the nation's skies.
In the examples given it sounds like ATC was doing things like directing aircraft in to restricted air space. Obviously the captain has final say and ATC’s role is officially just advisory. But this sounds like a bit more than a pilot who forgot how to navigate.
Restricted airspace, and airspace where GPS is disrupted, are different things. GPS disruptions can be vast. Unless you're flying around the Mojave, restricted airspace tends to be small and with ceilings that make it no factor for transport category aircraft. ATC should not direct planes into restricted airspace.
curious question: can navigational computers (on planes, though maybe this can be asked about other systems as well) not take an initial position-reading from gps or radio and then compute their location then-on based on internal gyros, compasses, accelerometers, etc.? if outside navigation aids fail, are these systems not capable of internally simulating and determining their own position, or am i underestimating how much compute power this would take?
The FAA is actually pretty good at regulating "known" things within its remit. It is however, exceptionally bad at regulating unknown things, so it has a defined process to make things known.
One of the most dangerous conditions at the FAA is when an unknown thing evades the FAA's process by which to make it known and understood to the FAA. It takes the agency a long time to grasp and assess. See 737 MAX, UAS...
The FAA is a giant lumbering dinosaur that has done as little as humanly possible to avoid any sort of modernization while drowning General Aviation in paperwork and regulations to protect a buggy-whip avionics and engine manufacturing/maintenance/repair industry, while for decades has failed to effectively address the primary safety issues in GA. Namely controlled flight into terrain and running out of fuel.
Let me give you an example of the idiocy GA pilots face; a relative is a plane-owning pilot.
The attitude indicator in many GA planes is a mechanical gyroscope, driven by vacuum from the engine, a vacuum pump, or a static port on the side of the plane. They are absurdly expensive, high precision devices and they have a huge failure rate. Repairing them is also very expensive. For decades, we've had superior technology: MEMS based accelerometers and rate sensors. Avionics using these sensors are incredibly reliable, very inexpensive, and switching to them is a royal fucking pain in the ass because of all the regulations and paperwork the FAA requires to do it. There's a massive avionics repair industry that has been in buggy-whip status for probably three decades, and the FAA is their little bitch.
He had an engine failure because his mechanic never changed an inexpensive part that was listed as required to be replaced on every maintenance interval. It turns out that despite all the FAA regulations, an aviation mechanic can go "meh, whatever" and ignore the factory repair manual for an aviation engine, even when the manual says "this is required to be done." Furthermore, the shop was listing the work as having been done, which meant they were generating fraudulent paperwork. This was also not against FAA regulations.
So the FAA regulates the fuck out of something like replacing 1940's technology with modern electronics superior in every way, but allows mechanics to fake paperwork and ignore factory repair manuals, and Boeing gets to say "oh yeah, FAA, we totally are doing all the things we're supposed to be doing", the FAA goes "mmm hmm sounds good" and then when four hundred people are killed, exactly nothing happens to Boeing management?
This is a case where a little knowledge makes everything look like a conspiracy. Sadly none of what you wrote is even remotely true.
Glass cockpit upgrades are very popular. For example, an Evolution E5 is $5k to $10k depending on the model. You can remove your vacuum system at that point. There's nothing stopping anyone from upgrading, aside from the cost. There's no conspiracy here, no evil FAA paperwork or regulations standing in your way.
> Glass cockpit upgrades are very popular. For example, an Evolution E5 is $5k to $10k depending on the model. You can remove your vacuum system at that point. There's nothing stopping anyone from upgrading, aside from the cost.
To me the cost is the obvious point of complaint.
Now I'm not an aircraft tech, but I'm looking through the manual for the E5 and as far as I can tell the $5000 base configuration gets you the main unit itself as well as an exterior sensor module. The main module of course houses the display, CPU, and battery as well as the IMU and pneumatic sensors for pitot/static and some serial ports for connection to other electronics. The remote module houses a non-certified GPS (connection to an IFR-certified navigation system is required for installation in IFR-capable aircraft), a compass, and a temperature sensor.
None of that is high-tech equipment, nor is the software required to turn those sensor inputs in to useful displays particularly complicated. I don't see any obvious reason a group of motivated electronics hobbyists couldn't build a proof-of-concept that performs all the same core functions over a long weekend with a few hundred bucks worth of off the shelf parts and access to the relevant details of the ARINC 429 standard.
Obviously there are reliability and redundancy aspects to consider, but even the E5 is only officially allowed to replace one of two instruments and everything else must remain in its original position. Reliable IMUs and redundant microcontrollers aren't the cheapest things out there but they don't make up an order of magnitude price difference either.
The regulations are there for a reason at their core, but there has to be some kind of balance where we don't have extra zeroes appearing in price tags just because something goes on a plane.
Of course! No one wants high-tech equipment in aviation.
> the software required to turn those sensor inputs in to useful displays particularly complicated
Relative to what though? This software has to always work. 100% of the time. If it ever goes wrong you might die. Software developers who are used to shipping normal code aren't used to the testing and rigor required in the aircraft industry.
> I don't see any obvious reason a group of motivated electronics hobbyists couldn't build a proof-of-concept that performs all the same core functions over a long weekend with a few hundred bucks worth of off the shelf parts and access to the relevant details of the ARINC 429 standard.
For sure. And hobbyists can also make experimental engines and aircraft. There's a whole category for those. But most people would not trust their lives to them. I wouldn't. There are too many edge cases, too many one out of a billion coincidences that will kill you in aviation.
Also, remember that they're not going to sell a lot of these E5s. These aren't phones. The entire GA fleet in the US is 200k aircraft. So they're going sell what, 20k of these over a decade worldwide? The low volume and the fact that you need to recoup your costs in a year or two at most, means that prices need to be very high.
‘ Furthermore, the shop was listing the work as having been done, which meant they were generating fraudulent paperwork. This was also not against FAA regulations.’
The FAA is part of the federal government. Are you seriously claiming there aren’t regulations penalizing those who submit false paperwork?
Are there NOTAMs regarding GPS jamming operations? It's not a fix, but maybe it would allow pilots - specially ones without sophisticated avionics like those founds in airliners(who don't rely on GPS in flight) - to prepare and/or avoid the issue.
It's impressively large - if I was planning a pleasant little flight in Denver or on the Gulf of California I certainly wouldn't be wondering what's happening at White Sands:
It really annoys me how far into an article you have to read before it becomes clear that they're only telling one, disputed side of the story.
> The US Army takes the safety of its operations extremely seriously. Calls for a cease buzzer are taken seriously and range control has not denied or ignored any cease buzzers.
The US Army and the FAA are two separate entities. The example in the article mentioned that a FAA facility manager might have denied escalation to use the buzzer, not the US Army.
I mean, the article is very clear that it's on-site management that are not allowing controllers to do their job; nowhere in the article do they suggest that the US Army doesn't take it seriously.
This is jamming and not GPS spoofing. Wouldn't the navigation system 'fail' and that pilot switch over to flying by heading? I would think the civilian craft would have to be robust in the presence of spoofing (military testing). ATC would declare a certain area as GPS off, a NOTAM or something.
Yes GNSS jamming and spoofing can interfere with road navigation. Due to signal propagation limits imposed by the ground and other obstacles the effective range will typically be shorter than with aircraft.
Can someone more familiar with the situation explain why they jam GPS at all?
You'd think the vast industry around the military could replace actual jamming with training aids. Even if the bespoke training tools are expensive, I doubt they're as expensive as an airliner wandering in to an active missile range. Not to mention the economic disruption to air traffic throughput.
The signal GPS uses is actually very very weak and can be jammed pretty easily just by spewing a bunch of noise in the general area of the spectrum where it lies. Military grade receivers have some countermeasures that civilian equipment doesn't (e.g. the military signals have much wider bandwidth to work with, and you can also do some antenna magic), but jamming is still a problem for them too and it's a pretty active area for R&D.
Just thinking about what that would involve. Very high gain antennas could track individual GPS satellites and probably defeat jammers. A phased array system (similar to Starlink's 'dishy', but probably larger due to the much lower frequency) might also work. Either solution would make many if not most uses of GPS either physically impractical and/or too costly.
GPS has a type of frequency hopping. Rather than jumping around from frequency to frequency, it slides up and down the spectrum like if you were turning an analog knob. The movements are determined by a pseudo random number generator unique to each satellite. Civilian GPS receivers have these PRNG keys so they can follow the movements up and down and stay locked on to the carrier while filtering any potential interference or jamming.
For military use they have a second PRNG that lines up with the civilian PRNG once every 10 cycles. So between every ping your phone or car GPS gets, there are 9 more military only ones that move around the spectrum randomly and have some other security features.
To jam GPS you either need the PRNG keys to know when to move your jamming, or just blanket the entire spectrum with random noise. If you take the blanket everything approach receivers may still be able to pick out the carrier (because it is moving and a detectable change).
(This isn't actually how it works, but is a simplified example of the concept. GPS is an amazing protocol that I don't even understand most of. There is some really cool stuff like using two different frequencies to measure the delay introduced by the ionosphere. The Coast Guard manages a lot of the civilian side of things and has plenty of rabbit holes you can go down: https://www.navcen.uscg.gov/?pageName=GPSmain)
You can defeat jamming in a fairly unsophisticated way by using an antenna that can only receive signals from a specific direction (i.e straight up), while everything else is filtered out. If the jammer is to the side or below you it wouldn’t do much good. The problem is for GPS to work you need to be able to see a few of the sats and some will be closer to the horizon.
"antenna that can only receive signals from a specific direction"
That's what "high gain" means; the main lobe is strongly focused in some direction. Actively tracking multiple moving satellites makes this approach mostly unworkable.
Speaking of Starlink, there was a news story posted here not too long ago about using Starlink satellite signals to determine location (within 8 meters IIRC)
The article makes it seem like they're testing the capability of field personnel rather than doing R&D.
For the actual R&D stuff, I can see why they'd need to do something in the field to see how it behaves. But I would also imagine that sort of testing to be fairly infrequent with long experiment cycles.
I spent years working on CPU validation. One classic method is random template based injection. You do three setup things: 1) pick a bunch of registers and busses that you will toggle to 1/0 in the RTL, 2) then code a bunch of mutexes of things that absolutely cannot happen (e.g., and AND cannot act like an XOR), 3) and then write checkers that look for bad conditions that should not happen. Then you press go literally run "coverage" by generating trillions of random test patterns and see if they toggle checker failures. There are behavioral tricks to reduce the search space (hierarchy helps), but it is one classic method. It can only be done a few times, so you really have to nail down your revision before you each up weeks of compute time on thousands of servers running random noise!
We've got submarine crews that can't avoid smashing nuclear powered warships into sea mounts. Switching off the crutches seems like a very necessary training approach.
SO the US military is heavily reliant on GPS, and they know it, and so do professionals on the other side. There is a lot of good reason to think that if the US gets into a Large State action, which is relatively unlikely but. . . , then the opposition will employ GPS jamming to negate some of the more smart and collateral damage avoiding systems. I've been out for almost a decade, so I don't know if secondary powers have reliable and ubiquitous GPS jamming capabilities, but I'd bet dollars to donuts IRAN has spent significant funding to acquire GPS jamming. All of this gives a a context for why the military both uses training aids (marker blackout over GPS, manually disabled data links, and whatever more high tech the have devised) and real operate in jamming training, possibly as final training, certification training/exams, if my experience in sibling forces is any guide.
Remember, GPS is a military tool first. Civilians get to use it at the militaries discretion. They could turn the selective availability (which was turned off in 2000) back on and remove a lot of civilian accuracy.
Maybe civilian pilots are the ones that need to training aids more than the military. It seems to me that they should be able to navigate without gps in a safe manner.
> In September 2007, the U.S. Government announced its decision to procure the future generation of GPS satellites, known as GPS III, without the SA feature. Doing this will make the policy decision of 2000 permanent and eliminate a source of uncertainty in GPS performance that has been of concern to civil GPS users worldwide for some time.
I think it is a moot point because there are 5 position constellations now days (US, EU, China, Russia, Japan) and many popular consumer chipsets can use multiple if not all of them.
It's not moot for aviation, where GPS units can be decades old, in part due to how expensive avionics are due to an absolutely mind-boggling amount of FAA regulations.
The FAA is a giant lumbering dinosaur that spends a lot of time making sure private pilots generate huge reams of paperwork and restricting the kinds of equipment that can go into various categories of planes, when the overwhelming majority of GA crashes are 1)controlled flight into terrain and 2)running out of fuel.
We'd have a lot less controlled flight into terrain if the FAA would unclench its avionics regulations asshole. Thankfully anyone can run an iPad with Foreflight, or any number of iOS and Android apps, that provide rudimentary terrain awareness and backup navigation.
> They could turn the selective availability (which was turned off in 2000) back on
I'm not sure if they can, if I've got the right info, block IIF and block III satellites don't have the hardware for selective availability; and those make up 16 out of 30 operational satellites (and one out of 4 reserve).
But I'm sure if they can't enable SA, they could likely just disable the civilian frequencies or something if needed. OTOH, there's GLONASS, Galileo, and BeiDou; the US can administratively deny GPS and probably Galileo, but not the other two, which makes SA less useful.
> Remember, GPS is a military tool first. Civilians get to use it at the militaries discretion.
That's a bit like saying Java could have dropped sun.misc.Unsafe at any time because it was a private API. Once the civilian economy started relying on GPS, the military had to consider the cost of turning it off. Not to mention that the U.S. military has traditionally been deployed to promote and safeguard American commercial interests, and if it started disregarding them, that would amount to a shocking political revolution.
> the U.S. military has traditionally been deployed to promote and safeguard American commercial interests
Any examples except maybe Kuwait? Korea and Vietnam were for geopolitical reasons, "to stop communists taking too much power", Iraq was few people taking advantage of 9/11 to line their pockets with government procured money. Afghanistan was the latter again. Which American deployment directly safeguarded American commercial interests?
As a lay person in this area... There are more navigation systems around: The EU Galileo, Russia's GLONASS, etc.
Assuming it's unlikely that all system are down/jammed/compromised in the same area at the same time, receivers for multiple systems should be OK...?
(Again lay person here)
GPS and Galileo have overlapping frequencies (this is by design) so if GPS is jammed then Galileo probably won't be available either.
GLONASS is historically less accurate and available than GPS (at least at lower latitudes) so I wouldn't be surprised if fewer (or no) aircraft have hardware for it
The majority of modern mobile phones will happily use satellites from all three systems for location. However yes, they generally aren't approved devices.
Can anyone identify the diagram in the bottom right of the article's image? The diagram is half covered by a form with some writing on it. The shape of the diagram has piqued my curiosity.
The DoD wants to ensure their forces can operate if GPS is down.
This requirement should be reasonable to most people who aren’t pacifists. So I think the real question is, why aren’t senior level DoD and FAA bosses doing more to increase safety during the planned outages?
You can always disable GPS at the edges. Or almost always. And, for the rest, yes, they should at least be talking to each other and publishing NOTAMs when possible (and ensuring the FAA has it covered when it's a surprise drill).
OTOH, would it be possible to have other location services such as Galileo, GLONASS, and BeiDou available as backups (or letting they all vote on your position)?
I would hope GPS denial tests also include the alt-GPS systems. Who knows what hardware might have unknown dependencies (one would assume military hardware has all been audited, but assumptions make for poor battle plans.)
But seriously "We've been told we can't ask to stop jamming, and to just put everyone on headings."... people inbound not ready for this can run out of fuel. Maybe the right passive aggressive response could have been to simply set a really large diameter TFR to keep civilian aircraft away assuming people check NOTAMs.
Instrument failures are rare and might impact a handful of aircraft; GPS jamming impacts every aircraft in the vicinity. ATC might have capacity to plan low fuel-consumption flight heading paths for a small number of aircraft, but not 100%?
ATC / radio failures happen. If ATC can't plan a route for you, you're still the pilot in command and responsible for finding a diversion airport and getting down safely, and for having had enough fuel to deal with traffic while doing so.
Sure -- I don't think the concern is literally falling out of the sky, so much as having to divert to another airport that isn't being jammed (inconvenient). But we're speculating on the basis of a vague complaint.
Would you be ok with a commercial passenger flight operating with 1 of the 2 engines completely disabled? It's technically designed to fly with 1 engine, so what's the problem?
Knocking out a pilot's GPS gives them one less tool in the event that other instruments fail. It's like saying "shouldn't you always be ready for backup hydraulics to fail?". Taking a backup system offline isn't an ideal situation.
You miss the point entirely. No commercial aircraft is going to be allowed to take off with only 1/2 engines in operation. If one goes out in flight they'll usually find a place to land bc it's understood that if that last engine dies then that's a bad situation. Which is the entire reason they have backups in the first place.
I'm not arguing about whether it's possible, I'm arguing whether it's smart. Airplanes have backups, and yes they can run on those backups, or else what would even be the point of having them? This kind of goes without saying...
If planes are DESIGNED to have backup systems, in case there is a failure, then do you think it's smart to arbitrarily remove one of said backup systems?
> No commercial aircraft is going to be allowed to take off with only 1/2 engines in operation.
That's a different question.
If you're knowingly flying into GPS jamming - these jamming operations are apparently announced via NOTAMs (https://news.ycombinator.com/item?id=28833002) - you should be planning ahead even more.
A pilot is responsible for having enough fuel in case of an emergency, like the GPS unit crapping out. Anyone running out of fuel due to GPS jamming was ill prepared for other emergencies.
Lol, I'm not saying pilots CAN'T operate without GPS (I fly hang gliders and I used to fly with literally no instruments at all).
Think of it this way. A person can live a normal life with 1 arm, 1 leg or even 1 eye or ear. Is it ideal? Probably not. If you lose your other arm, leg, eye/ear it's going to cause many more problems than just losing 1.
Losing any backups in aviation is a less-than-ideal situation. That was the only point I was trying to make. OF COURSE pilots can operate a plane without GPS, my god I'd hope they could. I feel like that kind of goes without saying.
You’re making a lot of specious arguments. I think your laymen’s logic checks out just fine here but that’s not how aviation works…and for good reason.
Taking off with 1 of 2 engines is a lot different than taking off with inoperative avionics. The FAA and airlines dictate what minimum equipment is required for any given aircraft to be airworthy and it’s a fairly robust document that takes into account myriad situations and flight conditions.
Yes that's even part of the verbal/written test. You have to calculate fuel requirements to different distances and they give you options that would be technically right but check to see if you pick the conservative approach in the event of this very situation. If you want to see how many people toss that knowledge out the window listen to some of the videos at VASAvation [1] and instead choose to land on freeways, city streets, farm fields, etc... Not all of them are due to fuel, but some are.
Also, "jamming" can include sending distorted signals. These distortions can be a spoofed or malformed packet of data. Knowing what happens when a navigation tool suddenly thinks the vehicle is on the other side of the world is important. As is, ensuring that a garbage signal won't crash it.
Is “them” civilian pilots or the soldiers? Because the military may have all sorts of equipment that has black box GPS functionality they can’t easily control (think of GPS guided munitions for example).
> The complaints accused the FAA of denying controllers permission to ask the military to cut short GPS tests adversely affecting commercial and private aircraft.
The issue according to the article is with the FAA, not the military
I would expect the FAA to select FOR social responsibility. In the military, sociopathy is sometimes an asset. At the FAA it is inevitably a liability.
There was an issue a few years ago in Chicago where planes at the airport were losing GPS reception, which was eventually traced back to a truck driver who used a jammer to avoid fines based on GPS tracker data on the rental trucks he was assigned to drive.
He wasn't intending to crash an airplane, just avoiding docked pay for driving in traffic, using a $50 device bought online, and his route took him past O'Hare.
The perpetrators aren't playing around to try to crash an airplane, they're merely polluting an invisible commons in their own self-interest, and aviation happens to need that spectrum to be clean.
Well the only reason military can own /pay for anything is because it takes our money in a first place. So unless there are specific security concerns civilians should be able to use whatever military tech they've paid for.
Military and government can pay for stuff also using deficit spending, which is not "our" money. It's either FED's money which they create (and thus steal value from us) or it's borrowed money from wealthy interests.
I wish you could download a lightweight map of the entire country. The way the selector rectangle works in my city makes it awkward to capture it well since its kinda longer east west rather than north south. If a garmin from 2002 could hold maps of the entire country, surely my iphone with 512gb of storage should be able to do it too.
That doesn't entitle them to access to military systems, either individually or as a collective. And surely citizens of other countries are not entitled to access to military systems.
The military serves the tax payer by preserving their sovereignty.
It's nice that they allow civilian use of GPS, but it doesn't follow that they need to. It's perfectly acceptable to say that a civilian organization, government or otherwise, is responsible for providing satellite-based location services for civilian use.
The way GPS is operated is very unusual. The military doesn't provide satphone service to people around the world; are you arguing that they should?
I think it’s for military protection. I had a flight canceled due to GPS jamming. I think it was to protect a U2 flight. Putin also flies around with GPS jammers.
Wouldn't that mean that Putin's flights can't use GPS to navigate? But maybe he worries more about someone intercepting his plane than he does about crashing due to a navigation mistake. And his risk assessment may in fact be accurate...
Obviously we navigated acceptably, including aircraft, long before the development of GPS in the 1970s. GPS is easy and precise and can make risky edge cases (like very low altitude flight) safer or allow higher density in air spaces and such, but it's not necessary particularly not at the government aircraft level. Inertial guidance, ground based Doppler navigation systems, and even automated celestial navigation in combo can produce great results just at a much, much higher expense. That isn't an issue for the leader of a major power though.
The SR-71 was a cool example of a system that used a hybrid of automated celestial navigation and inertial. Fully self-contained.
I'd assume a russian military plane would primarily use GLONASS. GLONASS has the advantage of being more resistant to narrowband single tone jamming because it uses FDMA rather than CDMA like GPS. The signals are also in slightly different frequency ranges.
There are other accurate systems for navigation available for aircraft, like the network of Non-Directional Beacons (https://en.wikipedia.org/wiki/Non-directional_beacon). It's a bit more of a pain in the butt to fly, because you're going from waypoint-to-waypoint, rather than a course relatively towards your destination, but it was how we did aircraft navigation up until relatively recently.
It should be possible for the jammer to subtract off its own signal rather more effectively than anything which doesn't have access to the pRNG it uses to generate the interference.
The thing is, GPS signals are really weak at the receiver. They're technically below the noise floor, and receivers have to use shenanigans to get a usable signal at all. If you're transmitting the jamming signal, you're really close to it, and therefore it is really strong near your receiver. I wouldn't like to calculate how many orders of magnitude stronger than the real GPS signal, but it would be a lot. Generally, subtraction works when the two signals are similar in strength, and you still lose definition in the received signal. GPS signals are so on the borderline of being able to be received that this would just not work at all.
I'm not sure that'd work very well as the primary strategy. A hot start can take 20+ seconds and the attacker has no particular advantage in time to fix when the interference stops.
Presumably Putin's flights, on Russian-built aircraft (specifically the Il-96), use GLONASS?
Of course, the VC-25A used as Air Force One has a cockpit station for a navigator, specifically so that it can use old-style navigation methods if access to GPS and other navigational aids is lost. Putin's modified Il-96-300PU may well also have one.
Yeah, the original 747s flat out had a sextant port in the roof. Could navigate by the stars the old fashioned way. Given how crazy precise (and expensive) inertial guidance systems were developed for ICBMs in the Cold War I have to imagine though they have one on Air Force One, along with an automated celestial guidance system for recalibration. The AIRS (advanced inertial reference system) used in the LGM-118A Peacekeeper missiles have to be some of the most mindblowingly precisely made machines in human history. Drift of something like 1.5/10000° per hour! .003° per week (not that they'd ever run that long obviously, ICBM and all). At any rate, highly precise IGS is doable for enough money, even with older tech though these days I'd assume they're using fiber optic gyros or something like that. It's a neat area.
This is the military practicing, but I would hope that civilian airline transport operations are also robust to GNSS unavailability or denial. Even private pilots in little Cessnas are taught to navigate using radio-navigation (NDB beacons, VORs, etc.) in the event that GPS is not available. You should absolutely be able to turn your GPS off and get to your destination.
The fact that radio-navigation aids are being phased out in favor of GNSS, turning it into a single point of failure, is pretty concerning.