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The World Economy Runs on GPS. It Needs a Backup Plan (bloomberg.com)
269 points by jedwhite 8 months ago | hide | past | web | favorite | 225 comments



Apparently Galileo, GLONASS and BeiDou don't count, because the backups for this backbone of the global economy have to be American?

https://en.wikipedia.org/wiki/GLONASS

https://en.wikipedia.org/wiki/Galileo_(satellite_navigation)

https://en.wikipedia.org/wiki/BeiDou_Navigation_Satellite_Sy...

I do wonder how many of these are supported by common hardware like mobile phones, anybody have a pointer to a compatibility list? I know the Chinese government had been prodding its manufacturers to add BeiDou support pretty hard.


All satellite nagivation systems are trivially jammable. They use DSSS to spread out codes and resist jamming but signal levels are still so weak at the surface it's trivial to block.

Most phones are compatible with GPS(US) +Galileo(Europe)+Glonass(Russia). Most of them also report which constellation the locks are from. GPS status and toolbox on android is a fun way to see what you're connected to.

What we need, and will probably get soon, is inertial guidance based on laser ring or fibre optic gyros in mobiles. You get a location fix every week or so and it starts out much more accurate than gps.

The US system was first by maybe a decade or more so support is nearly universal. The other systems are largely copycat, purposely compatible with existing GPS receivers.

That's why it seems like we're relying on the US for GPS, they invented it and had a full constellation in orbit before anyone else even thought of it.

Of course we're on the internet which was also invented by the US govt so I'm not so surprised why "the backups for this backbone of the global economy have to be American" in reference to GPS at least


> What we need, and will probably get soon, is inertial guidance based on laser ring or fibre optic gyros in mobiles. You get a location fix every week or so and it starts out much more accurate than gps.

Corrections every week? This isn't possible given the drift rates of high end FOG or Lazer ring IMUs. A high-end marine-grade INS can cost over 1 million dollars. These systems will typically provide un-aided navigation solution drifts that are less than 1.8 km per day. This means that if the device were left stationary for one day, due to slight errors in the sensors and imperfect sensor calibrations, after integrating the position solution, the calculated position after one day would be 1800 meters away from the sensors actual position.

With ones that you can affordably put in a phone within minutes the drift will be huge. You need something to regularly correct for the drift and currently this is GPS.


According to the paper, one nautical mile per day was state of the art in 2006. They are shooting for one mile/month now

https://link.springer.com/article/10.1134/S207510871401009X


Thanks I'm interested to take a look in detail.

From the abstract

> In 2006, we presented at DGON symposium in Stuttgart [2] the design and navigation results of MARINS, the first FOG-based navigation system within the class of 1 nautical mile per day. This navigation system in now in production...

> have we reached the limits of the technology or can we still improve the performance of our sensors?

> Of course, the present FOG design is not good enough for the required performance, even in a strictly controlled environment.

This is a discussion of how it could be improved not what is available in production and certainly not close to being available within a phone - which was the original point.


Fibre optic gyros can be miniturized to millimeter dimension, if it wasn't for ITAR.

High end civilian IMU's typically use mechanical gyros which have been obsolete for decades. Also, a phone isn't typically moving constantly like the oceans so error rates would be lower.


This is drift for a "static" million dollar marine grade (i.e. highest grade we currently have) INS not in the ocean or moving. Drift is measured in non-moving conditions. These are the fiber optic and laser sytems you are referring to.

Even if we could make that cheap and small enough it would still need regular corrections far more frequently than a week to be as good as a GPS is now.


You could use some smart heuristics to make corrections without a gps lock, like resetting the location to "home" if it is near enough and sits motionless over night, or making an adjustment whenever the location drifts too far from the known locations of currently connected cell towers.


You won't get close to GPS accuracy with these. The uncertainty from cell tower triangulation is huge (relatively). But yes, some kind of beacon that works like GPS on a local scale or detection of known mapped landmarks could be used for corrections but there are issues with these too. These could assist GPS location rather than replace it entirely.


> These could assist GPS location rather than replace it entirely.

Of course, that was the proposal. There's more datapoints if you're willing to get creative, wifi networks (already used for this), cooperative comparison with other mobile devices in a local meshnet, acoustic cues from the environment, machine analysis of captured images, etc. Obviously dead reckoning without gps is going to require a multi-pronged approach.


> cooperative comparison with other mobile devices in a local meshnet

Please explain how this will work?


I could imagine a secure location service that allows your phone to compare its current expected position with other nearby phones' expectations of their positions. If it's over bluetooth or wifi, the positions should be within meters of each other. This could provide an input to a kalmann filter type position estimator to help reduce drift as you (for example) walk down the street.


This doesn't make a lot of sense tbh.


What do you mean?

You don't think such a system is practical, or you don't think such a system is technologically feasible?

Or you just don't understand the system I'm describing?


I think there are both feasibility and practicality issues with the cooperative estimation scheme you are describing. Without already knowing where the phones are very accuratly there will be a lot of noise. Would need a lot more detail to really understand what you intend but first reaction is that it'd be very difficult to do well.

If you really care you could sketch out what exactly it is and how it'd work for yourself for a couple of devices (or more) and see what issues you uncover.


You might be right but I have doubts. Most weapons are INS guided despite the long fly times of cruise missiles etc. ITAR has a massive chilling effect on development, I wouldn't be surprised if we had error rates of less than a meter a day in mobiles if development wasn't severely curtailed


This works the other way - you get to prove your assertion that inertial navigation could work with cheap miniaturized sensors. Anyone can cast a doubt without proof.

If your acceleration sensor is off by 1 part per million, 9.8 m/s^2 (i.e. gravity) will turn into a positioning error of ~73km in one day.


Cruise missiles combine (using Tomahawk as an example) GPS, visual terrain-matching, radar terrain-matching, and INS. Because they know INS needs those constant corrections.


> Most weapons are INS guided despite the long fly times of cruise missiles etc.

And because of a long fly time or imprecise initial reference point (a submarine is floating) some do corrections. One of the coolest one for ICBMs is to use celestial navigation to correct errors. They'd have a window with a camera and would "look" for a few stars.


Drift is over a given time, not distance. Missiles generally have an very short fly time, even if they're going really far.


Cruise missiles are very different from (quasi-)ballistic or anti-aircraft missiles - they fly at subsonic speeds at low altitudes (usually using a turbojet) to avoid interception. For example, the classic Tomahawk flies at ~900km/h, with the long-range variants having a range of 2500km, giving a maximum flight time on the order of hours, and so a pure INS drift on the order of low hundreds of meters.


sensor fusion combines multiple sensors with different characteristics such as:

- GPS; widespread, low accuracy

- INS; always available, high short-term accuracy, terrible long-term accuracy

- terrain-matching: large-scale corrections.

The different characteristics allow one sensor to correct another to a degree to produce an overall stable position.



Not sure what IMUs you're using, but we've been using civilian MEMS and FOG IMUs for years now. You still can't make anything purely inertial good enough to keep position accurately enough to be a GPS replacement for more than a few hours.


Plus the gyros would have to be powered at all times -- that's not gonna work on mobiles.


So this is why my smartwatch can tell me my speed before it has a GPS lock, including indoors? Very cool! But of course, as you say, the reports of my absolute position are very inaccurate.


Velocity can come from dopplar shift of the GPS carrier frequencies. This is very accurate. An IMU can be used for walking speed estimation but it won't be as accurate using a human gait model or direct integration.


No, any position-solution produced before a GPS lock will be due to the approximation produced by either using the last-known position or the cell-tower triangulation. That information is also used as a seed for the GPS lock to speed up the time-to-fix.


> Most phones are compatible with... Galileo(Europe)

The system only went live in 2016. It's only been supported by Apple since the iPhone 6s, and Samsung has supported since the S8.

I would be hesitant to say that most phones are compatible. In 2016 most of the flagship phones had support but even having a compatible SoC doesn't mean it was implemented. The Google Pixel was released in 2016 with a Snapdragon 821 that is compatible yet the Pixel does not support Galileo.


There were predecessors to GPS: https://en.m.wikipedia.org/wiki/Gee_(navigation)


> What we need, and will probably get soon, is inertial guidance based on laser ring or fibre optic gyros in mobiles.

Isn't this precisely how accelerometers/gyros in mobiles work?



Thanks! I didn't know about those.

For some reason I was convinced phone gyros use light interference in a spiral of optic fiber. Probably because I read about that design when I was looking how solid-state gyros in RC models work.


> I do wonder how many of these are supported by common hardware like mobile phones, anybody have a pointer to a compatibility list?

iPhone X specs list "GPS, GLONASS, Galileo, and QZSS" [1]. I'm pretty sure they've supported multiple GNSS systems for a few generations.

I know I've seen several GNSS modules from u-blox that support multiple GNSS systems as well. One example, NEO-M8, supports "BeiDou, Galileo, GLONASS, GPS / QZSS." [2]

I know I've also seen several cheap GPS modules that are GPS-only, so multiple GNSS support isn't ubiquitous, but it's probably ahead of IPv6 adoption.

[1]: https://www.apple.com/iphone-x/specs/

[2]: https://www.u-blox.com/en/product/neo-m8-series


Any ill that would befall GPS could easily also affect those. The issue is "a shocking amount of critical infrastructure depends on positioning/timing information derived solely from a handful of satellites broadcasting weak signals in the 1.whatever GHz band", whoever runs the ground segment for these constellations is immaterial (to first order) and "GPS" is just layman terminology.

Also eLORAN when?


The real answer is star navigation at night and interial + sun guided during the day. Phone hardware is perfectly capable but ITAR says otherwise. There's a reason why every legal GPS receiver shuts down after altitude or speed limits are exceeded. Too easy to make weapons that fly in your window from hundreds of miles away, basically


From mynameisvlad link given below[1] the restrictions are to prevent intercontinental missile navigation not regular missile navigation. The official limits are a speed (1,000 knots) and an altitude (18,000 m), but many manufactures do an "or" test instead.

"In GPS technology, the term "COCOM Limits" also refers to a limit placed on GPS tracking devices that disables tracking when the device calculates that it is moving faster than 1,000 knots (1,900 km/h; 1,200 mph) at an altitude higher than 18,000 m (59,000 ft).[2] This was intended to prevent the use of GPS in intercontinental ballistic missile-like applications.

Some manufacturers apply this limit only when both speed and altitude limits are reached, while other manufacturers disable tracking when either limit is reached. In the latter case, this causes some devices to refuse to operate in very high altitude balloons."

[1]https://en.m.wikipedia.org/wiki/CoCom



Is it really so hard for a determined terrorist to build his own gps receiver? Or at least modify one to remove that limitation?


They don't need to. There is a great many of more cost-effective ways of causing havoc, and even if they really wanted to use GPS-guided missiles, it's probably a better bet to build slower missiles with consumer hardware, but build a lot of them - missile interceptors are very expensive. If a DIY $1k missile needs to be shot down by $1M Patriot, they'll be doing lots of damage with a couple of them, without even hitting anything.


Yes. Look at the ham hobby, hardly any of them can pick up GPS signals, despite the technology being literally everywhere


That's not true at all. You can use a $20 SDR card to receive GPS signals and and then can decode them on any commodity laptop, or a small computer like a raspberry pi.

e.g. https://www.rtl-sdr.com/receiving-gps-with-an-rtl-sdr-dongle...


Receiving the signals is only a part of the problem, and even getting a "fix" isn't all that hard. Maintaining an accurate fix, and at the same time refining away previous errors, on a fast moving vehicle, is a dark art.


Software architectures are the limiting factor here.

Every app on your phone cares about "Where am I now", but no app wants to know "Where was I 5 seconds ago, but with more accuracy than you knew when I last asked".

Neither android not iPhone have an API to allow GPS hardware to refine the accuracy of historic position locations.


Possible maybe but unusual. 99% of ham is narrowband, GPS is spread across a megahertz. Somebody goofed and made a TV tuner chip that could be used as an SDR at that sample rate, and I'm sure the powers that be arent happy.


You what?

Any sensitive Spectrum Analyser or SDR can see the bump in the spectrum caused by the GPS Signals. And quite a few amateurs have built homebrew GPS receivers.

Or they can buy a little GPS module and use the data stream for a huge range of projects.

Most modern digital Ham communication methods require a 10MHz feed from a GPS module to maintain sufficient time and frequency accuracy.


Too late to edit so replying to myself. I was mostly wrong. The GPS limits are much higher than I thought, and accuracy of INS is too low, although I still think that limit is artificial.


Yes the real answer is some impractical nonsense. Star navigation? Are you serious?


I beg to disagree. My phones have all gotten a lock on planes so far.


The limits are higher altitude and faster speed then you've ever been. If the Concorde was around you would see it firsthand. Weapons would be worthless against first world defences at airliner height and speed. Gps receivers shut down on weather balloons regularly, it's a known issue

The limits are real, encoded in public law. I don't understand how you could possibly disagree with me on this point


Ignore the comment above, obviously ignorance :) Thanks for explaining.


It's okay, I was wrong about what the limits are too. They've been increased a lot


The reason your GPS receiver does not work on a plane is likely because it's processing algorithms aren't tuned for those speeds. The popular Ublox NEO-6M for example needs to be explicitly switched to "airborne" mode.

The fact that you are enclosed in a faraday cage also isn't helping, but they make planes from plastic now, so this shouldn't always be the case.


Planes don’t usually reach the limits, but they exist. The limits seem to be 1200mph or 59000ft altitude.

https://en.m.wikipedia.org/wiki/CoCom


1200mph and 59000ft altitude


Unfortunately many cheap GPS chips use the (incorrect) or definition, not and. It was a pain to find one that works above 59000ft but very slow speed for a weather balloon project some years ago.


I like using a NSF funded mobile app "Flyover Country" [1] to identify features in the landscape when I fly. You can download the maps and data for you flight path a head of time and then use it in airplane mode on the plane. GPS works fine (by the window) and the app locates your position on the map.

https://flyovercountry.io/


Odd that you'd think that aircraft would be covered by these restrictions considering the fact that they use GPS to navigate.


There's not a ton of civilian craft cruising about at nearly Mach 2.


> Any ill that would befall GPS could easily also affect those

The linked article that we're commenting on was about a software bug in GPS only

The root cause was a bug in the GPS network. When the U.S. Air Force, which operates the 31 satellites, decommissioned an older one and zeroed out its database values, it accidentally introduced tiny errors into the database, skewing the numbers


eLORAN never seems most likely now LORAN-C has been decommissioned and after 20 years of talking about it.


GLONASS is supported in every major GPS-receiving chipset these days (including those in smartphones, etc), because Russia put a huge import tariff on any satellite navigation equipment that isn't GLONASS capable. So the manufacturers of such, who were already doing it, made GPS Rx chips that also listen to GLONASS.

https://books.google.com/books?id=DuoKFiZKbwEC&pg=PA5&lpg=PA...

https://thenextweb.com/apple/2011/10/21/the-iphone-4s-glonas...

this is pretty old news.


Galileo is catching up too. There is a supported device list here: https://www.usegalileo.eu/EN/. In addition, Galileo was just added in a recent software update to some Garmin watches. (Interestingly, they have supported GLONASS for a while.)


> I do wonder how many of these are supported by common hardware like mobile phones, anybody have a pointer to a compatibility list?

I see GLONASS compatibility on "the specs" list of almost every smart phone on gsmarena[0]. Even iPhone 4S has it. Just did a quick look-up, newer phones now support GALILEO and BDS too.

[0] https://gsmarena.com


Others have already pointed out that these systems are also susceptible to the same types of jamming/interference.

Two other issues - the biggest one is mentioned in the article - global coverage. GLONASS is the only one to claim global coverage.

The other issue is that there's still a huge number of devices that don't support those systems. Most of the time if something says it uses/depends upon GPS, it means literally just that one system, not the others.


As far as I know, all of those constellations are vulnerable to Kessler syndrome. Ground-based equivalents (eLoran) wouldn't be.


GPS satellites are in an unusual orbit (between LEO and geosynchronous) where there is not a lot of debris. They’re also highly redundant and the constellation can lose several satellites without dropping service. Jamming is honestly more of an issue than debris.


>the backups for this backbone of the global economy have to be American

Where does the article say that?


It focuses squarely on GPS and proposed American solutions to make GPS (only) more resilient, while ignoring the other three operational backups the world does have!


The article mentions all those systems by name. Of those, only GLONASS has global coverage (also mentioned in the article), and it is operated by a hostile state.


Off-Topic: Is HN primarily serving the US/Western audience? There might be some areas in the world where Russia is apparently "not" a hostile state?

I must apologize again for going a little off-topic


> There might be some areas in the world where Russia is apparently "not" a hostile state?

Very few. The Kremlin and the presidential palace in Damascus come to mind, but Russia is actively antagonizing the rest of the developed world, including the areas just outside the walls of those two.


HN is English-language, so it's a strong assumption that the majority of users are English speakers. Russia is to some extent hostile to all the major English-speaking nations (in large part because all of those nations are strongly allied).


Isn't India English speaking? And HN has a huge Indian demographic I would imagine.

And historically, I believe they have been allied with the Soviet Union whilst the USA has historically allied with their arch-rival Pakistan.


Russia is a hostile state to the average Russian, too. It's an unaccountable kleptocracy.


Everyone is a hostile state to someone. Except maybe Switzerland. ;)


In case they start launching satellites I'm gonna trademark the name SwiGNSS.


It is pretty widely accepted that the global economy is dependent on America.


Dependent is a strong word. If the USA disappeared tomorrow, the rest of the world would reorganise quickly enough; the global economy would settle into a new normal within a few years.

I'd go out on a limb and assert that if China disappeared tomorrow, the consequences to the world economy would be far more devastating. So much of the global economy is tied—directly or indirectly—to Chinese manufacturing. It would take multiple decades for the world to replace the supply chains and highly skilled labour.


It would not be normal in a few years. The US is also a very large manufacturer, much of which is in more "essential" goods such as large equipment. Individuals and governments across the world hold US treasuries, so the US disappearing would wipe out trillions of dollars of assets. The US currency is a common reserve currency across the world, and would become worthless, creating a massive domino effect in banking across the world. Many important internet services would no longer function. Countries like Japan and Israel which rely on the US for defense would suddenly face a decrease quality of life and even existential threats. The countries which rely on US aid would suffer greatly.

Is the world dependent on the US? No, you're right that dependent is a very strong word. However, the US, for better or worse, provides a very high amount of global stability. The US has a massive economy and a very strong military, and the world would be very different if any country like that were to fail.


While losing China would certain set off shockwaves, I'd say you are in fact on a limb and have it backwards. Manufacturing can be moved and trivially ramped over a few years, perhaps at great cost, but still, only cost. Advanced technology, culture, and other elite exports are not so easily moved to Bangladesh or Vietnam. I'll go out on a limb and say losing Japan would be a bigger loss for the world than losing China due to this. Things I own that are made in China, or have parts made in China, are mostly owned for the cheaper price, not for any uniqueness. Japan and the USA export unique things which cannot be replaced by merely paying a higher price. Losing Google alone would set the world years back. Losing America would scramble world culture entirely (maybe for the better, you say, but that's a value judgement). Whereas China is so insular, the world would move on quickly.

It depends on what you value, I guess.


"There's a confusion about China. The popular conception is that companies come to China because of low labor cost. I'm not sure what part of China they go to but the truth is China stopped being the low labor cost country many years ago. And that is not the reason to come to China from a supply point of view. The reason is because of the skill, and the quantity of skill in one location and the type of skill it is."

"The products we do require really advanced tooling, and the precision that you have to have, the tooling and working with the materials that we do are state of the art. And the tooling skill is very deep here. In the US you could have a meeting of tooling engineers and I'm not sure we could fill the room. In China you could fill multiple football fields."

-- Tim Cook, from this article: https://www.inc.com/glenn-leibowitz/apple-ceo-tim-cook-this-...


The global economy is dependent on all of the largest countries. Try removing China and see what happens.


Widely accepted in America perhaps. I'm willing to bet that removing China would have much more of an impact.


No. It is pretty widely accepted that America (i.e. US) is dependent on the global economy.


The longer I am alive the more I learn about how much of human civilization depends on good faith and trust. Nearly every major system in use today is chock-full of single points of failure that could have catastrophic consequences but we keep chugging along, rarely stopping to think about the "risk debt" we have accumulated - right up until a catastrophe. I don't know if that should make me feel more secure or terrified.

Take power plants for example: they are all interconnected in large regional grids and deal with such large quantities of power that bringing a power plant online is a dangerous process that has to be coordinated with the rest of the system. You have to spin up the power plant and make sure that you are in phase with the grid before connecting your power output - all while accounting for geographic distribution losses, predicted load changes, and so on. Theoretically, any discrepancies (like power flow being too high due to phase difference) would activate breakers and other safeties should an adversarial actor decide to bring a power plant online online willy-nilly. Unfortunately, the last few decades have shown that those safeties are barely able to handle common scenarios, let alone an attack. There is a serious risk that a single power plant could cause systemic damage to many devices in a region's grid but for the entire history of the US, we have just assumed that anyone with tens of millions of dollars to invest in a power plant is just too profit-driven to pull off anything like that.

If the last few years (decades it seems) have taught me anything, it's that we have to reevaluate many of the assumptions we have been holding about reality and our peers. From the Target/Home Depot/Equifax breaches to Facebook's Cambridge Analytica fiasco, we have just been way too lucky and way too trusting. GPS is just one of many such cases, although a surprising one. I never thought the world would put so much trust in a system created by and for the US armed forces.


> The longer I am alive the more I learn about how much of human civilization depends on good faith and trust.

The way I see it, this is a feature, not a bug. The energy costs of trying to build a civilization like ours on trustless systems would be prohibitive (and no one would be happy about the amount of bureaucracy it would involve).

Trust is not only vital to the continuous existence of our civilization, it's also a very powerful tool for advancing it. That's why the growing lack of trust of the general population worries me. The rule of law works only as long as most people trust in its implementation. Money works only as long as most people trust in its implementation. That's why, for instance, I'm very critical of mainsteam journalism and media platforms - all they seem to be doing these days is to sow discord, burning people's trust in institutions to get their eyeballs. That's why I've been so critical of Uber since the very day they entered the taxi market, as by breaking laws and getting away with it they were eroding trust in the rule of law (half of the blame goes to municipal governments that failed to immediately ban them).

In my view, trust is so important that working to destroy it is antisocial behaviour, and one that should be punished swiftly and severely. Much more than it is these days.

--

> If the last few years (decades it seems) have taught me anything, it's that we have to reevaluate many of the assumptions we have been holding about reality and our peers. From the Target/Home Depot/Equifax breaches to Facebook's Cambridge Analytica fiasco, we have just been way too lucky and way too trusting.

IMO the examples you give aren't very powerful. Nothing significant happened because of Target/Home Depot/Equifax breaches, nor the Cambridge Analytica fiasco led to anything of relevance - when compared with the previous scenario of power grid failures. I'd use the 2008 financial crisis as a better example.

> GPS is just one of many such cases, although a surprising one. I never thought the world would put so much trust in a system created by and for the US armed forces.

What about the Internet? ;).


I think you are spot on in the first paragraph that trust is critical for existence and advance of civilization.

That trust somehow builds consistently in small groups -- humans seem good at quickly deciding, based on a few personal experiences, whether to deal with / trust another person. The major challenge is that this approach does not scale -- one does not trust strangers in a large city. Using a few trusted agents (newspapers, TV, etc.) for things you cannot personally see and assess kind-of worked 50+ years ago, but that model has now failed.

IMO building a framework of trust in a larger, denser, more interconnected world, is one of the major existential issues for a modern civilization. Allowing folks to organize in smaller groups (and set their own rules) and not forcing mixing based on federal laws might be a start. It might work better that universal doctrines ("trust the state"), universal technology ("trust the app") or behavior changes ("trust a stranger"). My 2c.


> The way I see it, this is a feature, not a bug. The energy costs of trying to build a civilization like ours on trustless systems would be prohibitive (and no one would be happy about the amount of bureaucracy it would involve).

Oh, absolutely. Don't get me wrong, I fully believe in a trust-based cooperative world. I mean more to emphasize that we aren't really doing any analysis on the risk debt we are accumulating through profit driven global development. Without putting some time and thought into it, we can't make decisions about which risks are acceptable to keep long term and which ones need to be revisited.

> Trust is not only vital to the continuous existence of our civilization, it's also a very powerful tool for advancing it. That's why the growing lack of trust of the general population worries me. The rule of law works only as long as most people trust in its implementation.

Again, I agree, although I don't how you'd go about justly identifying such behavior, let alone enforcing and punishing it fairly.

> What about the Internet? ;).

GPS is a special case because of how expensive geosynchronous access is and how few the points of failure are. The US could just turn off the spigot or Russia/China could shoot down the satellites - the GPS signal they send out is basically a giant homing beacon so it's not as difficult as shooting down spy satellites - and that's that. The tech for laying fiber and connecting to the rest of the world is far cheaper and more accessible making it much harder to disconnect an adversary completely. It's easier to trust a system built to be decentralized instead of dependent on a single constellation.


> Again, I agree, although I don't how you'd go about justly identifying such behavior, let alone enforcing and punishing it fairly.

It's a difficult problem and I'm not sure what even approaches a good - and stable over time - solution; naïve approaches would quickly degenerate into totalitarianism...

> GPS is a special case because of how expensive geosynchronous access is and how few the points of failure are.

Fair enough :). I was just addressing the "created by and for the US armed forces" angle.

Satellites are fragile, but they're also very expensive to shoot down. So I think GNSS systems are pretty safe, as points of failure go. Random rogue actors won't be able to afford destroying them, and if anti-satellite missiles start flying, we'll have much bigger problems than lack of satellite navigation systems.


It should be noted that you don’t need satellites in GSO to triangulate signals between satellites and the ground. It’s not a much more difficult technical problem to have a table of the full ephemeris data for a bunch of satellites in lower orbit, and use that information in GPS receivers. It’s just that our current chips wouldn’t be compatible with receiving data such a system.

IMO the Kessler Syndrome is overblown as a risk. Most of our space infrastructure would go to hell in such a scenario, but it’s not an existential threat like it’s often made out to be.


> IMO the Kessler Syndrome is overblown as a risk. Most of our space infrastructure would go to hell in such a scenario, but it’s not an existential threat like it’s often made out to be.

It's not a threat to existence of life (or civilization) - though losing satellites would have severe economical and geopolitical consequences. GNSS systems are one thing, but then there are also weather satellites, climate observatories, satellite comms, emergency beacon tracking and spy satellites.

The main worry here is that a full-blown case of Kessler syndrome would simply lock us out of space access for couple decades or centuries, depending on the severity of it. You could forget about satellites. Space probes might work if launched straight into some transfer orbit. Manned missions would be most likely deemed too dangerous.


Existential was the wrong word to use. What I mean is geared towards your second paragraph - that we won’t be locked out of space. Our current systems are in a pretty narrow range of ideal orbits which would get cluttered up. But there’s a lot of room in sub-optimal orbits that would still be clear, and can still be used for everything we do today. Just at a little higher technical cost.


> That's why, for instance, I'm very critical of mainsteam journalism and media platforms - all they seem to be doing these days is to sow discord, burning people's trust in institutions to get their eyeballs

And yet here you are, sowing distrust in the media!

This isn't an indictment - I do agree with you on both fronts. I'm pointing out that it's decay-turtles all the way down.

The issue with trust is that it doesn't scale. Or really, as soon as people start trusting symbols (eg institutions), concentrated value is created, which then is profitable to arbitrage away. With the overall trend of increasing communications, we are better able to observe this behind-the-scenes selling out, and thus our trust is eroded.

If we wish to restore faith in our institutions (ie make them trustable again), we need to move their philosophy and governance from "trust" towards "trust but verify".


> And yet here you are, sowing distrust in the media!

Touché.

> Or really, as soon as people start trusting symbols (eg institutions), concentrated value is created, which then is profitable to arbitrage away.

That is the most succinct way of expressing this that I've ever seen. Thanks! It also explains the problem in terms of the same forces that also drive markets, which sounds very plausible (due to simplicity).


Beware that I haven't gotten much utility out of it beyond unbridled cynicism.

Amazon making bank by coasting on a shared hallucination that their prices are competitive isn't really a big deal, societally. The popping of that bubble won't be a big deal either.

Having people view peace officers akin to an occupying military force is a problem (but so was the routine criminality of police before the median person became aware). The troubling bit is that rather than these institutions attempting to self-reform (eg just start prosecuting uniformed criminals), they seem to be digging their heels in - aiming to preserve their power rather than aiming to preserve their justification.

Of course this is the same model-precessing modus operandi common to all established organizations, which is why they die so hard. I think the ethos of creative destruction is so baked into our society that we really don't know how to deal with these organizations that have been adopted as institutions and will not simply be left to fail in isolation.


It's a great way to frame the current political climate and several crucial periods in American history. The author didn't exactly phrase it that way (he is a historian not an economist) but I'd recommend The Republic for Which It Stands by Richard White from the Oxford History of the United States series. He starts out the acknowledgments "I have written a book about a time of rapid and disorienting change and failed politics, and now I finish it in a parallel universe" and goes into great lengths about the failure of institutions as they tried to rebuild during the hyper polarized post-Civil War Reconstruction era. Reading it is quite unsettling at times because the later years look almost exactly what is happening now with privatization and erosion of government - symbols that were rapidly arbitraged to the highest bidder.


Trust is two way. One of the reasons uber got away with things is the taxi system already wasn't well trusted. Municipal governments didn't help me restricting taxi licenses to increase prices. That is uber got away with it in part because the rule of law had already failed.


A default trust society can be much more successful than default deceive/don't trust society. The cost of default don't trust is high. I would say that the wide adoption of the Christian value of honesty with everyone is probably one of the main reasons for the rise of western Civilization. If we decide to go back to a default don't trust society, we will loose something very valuable. We should try very hard to avoid that.


Please don't inject religion into HN threads. Nothing good ever comes of it.


I should have left the word Christian out. It was not really needed. By the time I saw what it had spawned, it was too late to edit.


Yes, it really does boil down to just that word. We can speculate about the reasons, but the effects on a large forum like this one are predictable.


The problem with excluding religion is that it's relevant. Imagine excluding any other branch of philosophy (science, math, photography, morality, logic), and the effect it would have on conversation. It would make no sense, and it would make it impossible to have meaningful discussions about many topics, as well as impossible to arrive at certain truthful conclusions about them. To exclude religion is essentially a (very closed-minded) religion unto itself.


I absolutely agree in the first bit. I'm a strong believer in "trust but verify" where you develop relationships based on trust by default with a healthy layer of auditing to inspire confidence long term. My concern is that the ROI of trust by default in the past has opened up our contemporary systems to an unprecedented attack vector.

The surprising part is that this phenomena has extended to geopolitics: having control over the GPS constellation is the kind of thing that would have single handedly decided both world wars, yet is now taken for granted by intelligence operatives of hostile nations using our GPS system. It's hard to believe it's worked for so long.

As for the Christian value of honesty stuff, I strongly disagree. Communities of chimpanzees and prairie dogs!! commonly exhibit social behaviors that would be indistinguishable from humans despite the fact that they have no formalized moral framework. Chimpanzees or prairie dogs who yell wolf too many times will be ignored. Those that are dishonest or manipulative are shunned. Those that are too aggressive are put down by the tribe.

Christianity has nothing to do with it. Honesty is a necessary trait for survival of any complex species dependent on communication for survival


> trust but verify

That's not trust.


It can be. You can trust someone to have done the job like they claim, but can still verify it to make sure they did it correctly. A second set of eyes rarely hurt.


That's not quite right; the point of "trust but verify"[0] is to assume in the short term that they did the job they claim (correctly, even), and start doing work that depends on it, but verify in the background, and roll things back if they didn't. This gives you some of the benefits of a high trust environment while still coping with the occational lying scumbag.

Of course, if it's fast/cheap enough, you can go with the much superior "verify and don't even waste time asking", but that's often impractical.

0: Well, the steel-man interpretation anyway; the historical version seems to just be a euphemism for "Don't trust, but claim you do so they look bad if they try to complain about it.".


I think the whole bone of contention with the statement is pretty much a semantic argument.

What is "trust"?

In your scenario, I wouldn't classify it as trust at all, yet I know I've used that word to describe something similar when describing building software.

But if you wanted to pin me down, I'd waffle and say, yeah, I'm not really talking about trust. If I trusted function X, I wouldn't check anything about it, I'd assume it's right.

So in your scenario, I wouldn't classify what you were doing as platonic trust either. I wouldn't call it trust unless the verification came when the deliverable was due. But then by then, your trust has been violated.

For instance I ordered something online. I trust the information FedEx gives me is accurate. It says my package is delivered. I am going home and I expect to see the package at my door. I trust my neighborhood/apt complex enough that I don't expect it to be stolen. That is trust. I don't have anything to confirm what I currently believe, but I still believe it.

In contrast, I stopped trusting the USPS at my old apartment. Because a couple of times, they've claimed a failed delivery attempt even when I was home. So I stopped expecting things to get delivered when they said they would be when they would come through USPS.

And I never trusted packages to be delivered to the house I lived at before that place. I'd get things delivered to work.

When people tell me they "trust, but verify", I tell them it's either or. You can trust or you can verify. When they tell me they trust the results of my work but want to verify it, I explicitly tell them, "I don't want you to trust it, I want you to double-check me to make sure I got it right. I don't fully trust myself. Accuracy is important, I want a critical eye on this in case I missed something. I don't mind being wrong if it means we are right."


> I think the whole bone of contention with the statement is pretty much a semantic argument.

> What is "trust"?

Actually I was talking exclusively about the phrase "trust but verify". Absent context, "trust" is like "know"; it's a useful shorthand but shouldn't be used if you're trying to speak rigorously about what's actually happening.


Yeah, that's why the "verify" bit is so important.


The point is that "trust, but verify" has two too many words.


It's a bit parochial to hear someone in the twenty-first century describe honesty as a particularly Christian value. You do know you're talking to the whole world here? Most human cultures have valued honesty to a similar degree. Even many animal communities value honesty.


Religion has historically and continues to play a major role in geopolitics... there's nothing parochial about it. The Christian belief system was objectively instrumental in the creation of the West's institutions, system of government, beliefs about trade, etc. You don't have to be religious (as I am not) for this to be true.


People, especially Americans, conflate Christianity with Western culture. But this is erroneous thinking:

1) Western liberal values are not co-extensive with Christianity. Christianity is geographically much larger. This has been true historically, and even more true today with the rise of Christian nations like South Korea and various nations in Southern Africa.

2) Western liberal values came to predominate in Europe centuries, even millennia, after Europe was Christianized.

3) Many Western liberal values are easily traced to pre-Christian movements, such as Greek Stoicism.

4) The Christianity of most Western Europeans today is not the Christianity of centuries ago, let alone millennia ago. The Protestant Revolution was like a giant flask where people took Christian doctrines and mixed them together with contemporary civil and philosophical values which emerged from the Enlightenment and then the dawn of the scientific and industrial ages. It's one thing to say that Christianity was conducive to the emergence of those other phenomena; it's quite another to say that they were Christian.


1) Christianity has been a major export of the West through missionaries and colonization. It was hardly the native religion of, say, Mexico or the Philippines.

2) That's hardly a compelling case against the influence of religion on Western values. It could even be a contributor, or neutral.

3) These values were well-documented but, for whatever reason, did not spread to the Muslim or Hindu world first. Islam had its brief progressive renaissance but was not able to sustain liberal values over the long-term. There are some small exceptions - Ismaili Muslims are quite liberal - but they're a tiny fraction of the Islamic world.

4) America was essentially founded by religious zealots and/or adherents to marginalized religions. The very architecture of early America - the gothic styling of Boston, for example - is of that era and persists. You can't wipe out that kind of influence in 100 years.

I'm not saying religion is the ONLY factor, but I find it odd that people try to ignore the impact it's had on the shaping of the modern world. I'm an atheist so I view this more as a historical fact - I'm not a fan of organized religion and would be perfectly happy if it went away.


It's a problem of timing and geography. Eastern Orthodox falls under the Christian religious umbrella, but it's very different under the surface demonstrating how western culture has influenced Christianity.

The Protestant Reformation was a religious movement, but ended up importing a lot of western beliefs into Christianity. Democracy for example is a western belief, Christianity is closely tied to Kings.


Nobody is arguing that religion did not have a substantial and dramatic impact on western culture, though it's disputable whether much of that impact was at all positive, let alone a net positive.


EDIT: wahern's reply above is far better than mine. Read that one instead. I'm removing most of what I originally wrote except for this bit:

-----------

I would argue that Christianity has influenced western culture far less than western culture has influenced Christianity. And that the key benefit attributable to Christianity—insofar as it was the lucky religion which happened be closest to the people who built western civilisation—is arguably its adaptable and relatively non-invasive nature compared to many of its contemporaries.


We do have a parallel universe. Christianity and "the West" are not co-extensive. Christianity was and is much more widespread. The West emerged from a corner of the Christian universe, and what made that corner unique is readily distinguishable from Christianity. At best one could say that the Christian universe was relatively more conducive to the emergence of Western values.

For example, Christianity is tolerant of the concept that God primarily operates indirectly through physical laws, a concept which was normatively rejected early in Islam (circa 1100). Thus, Christianity was relatively more conducive to the emergence of science. But, Christianity is hardly the only religion so tolerant, so it's not like it deserves special credit in that regard. Indeed, this tolerance is sort of a fluke and really a vestige of Roman and Greek influence--influence that Muslim scholars were deliberately rejecting.


Western philosophy predates the Christian belief system. It's slightly more accurate to say Christianity was influenced by western culture than western culture was influenced by Christianity. (Though clearly adoption occurred in both directions.)

Christmas trees and holly are obvious, but compare old vs new testament and it's much deeper than that. On top of that you get the Protestant Revolution which really westernized Christianity.


They were talking about the rise of western culture, for which Christianity is the major religion.


And they were talking as if "don't trust" was the default before Christianity, which is wrong, absurd even.


Human and technological development in spite of Christianity and other religions.


I've not heard honesty considered a peculiarly Christian virtue. They're sort of orthogonal.

Perhaps you're thinking of guilt and conscience, which means people might think that not being affirmatively honest could be considered wrong. Christianity is sometimes conflated with guilt culture (which emphasizes personal conscience), but Western guilt culture comes from Greek Stoicism and it took awhile to permeate through Europe--much longer than Christianity (like millennia longer). And there are plenty of modern Christian converts (entire countries, in fact) which are devoutly Christian but absolutely have not internalized a guilt culture. Very little, if anything, about Christianity requires a guilt culture--indeed, all of the Old and much of the New Testament is perfectly consonant with a shame/honor culture.

Note that not telling the truth is not the same as lying. For example, you could choose simply not to disclosure unless asked. Also, the Abrahamic commandment, "thou shall not lie", aka "thou shall not bear false witness against thy neighbor", was a legal rule. Most societies have this rule. Twisting it into a personal moral rule about how you go about your daily life is a result of our guilt-based culture which, again, is separate from Christianity, per se.


Barring the Christianity angle, I strongly agree. Trust is a very powerful optimization that humans have figured out. It gives us absurd efficiencies across the board - because without it, we have to add lots of complexity to verify things, and then some more to patch loopholes.

That's why I'm suspicious of technologies and systems that are meant to be trustless. They seem like a step in the wrong direction.


Human values are not derived from religion; religions are built around existing value systems - to the point of misappropriating them.


Rational arguments are not derived from gonvaled; gonvaled is built around existing rational arguments - to the point of misappropriating them.


Maybe you could provide an example moral value which was introduced by religion, and not appropiated from the already existing society?


There are a few problems with your request.

One, it's stated vaguely. What would qualify? Which religion, and which society? You would likely claim that there was some society somewhere which already had such a standard, and that therefore religion had nothing to do with it. It's too easy for you to dismiss any example because your requirements are not well defined.

Second, how far back are you willing to go? Go far enough back in human existence and we can't trace the provenance of a certain moral value.

Third, it depends on your existing beliefs about religion, creation, etc. If you believe that humans were created by a creator being who endowed them with certain abilities and tendencies, then who's to say whether a certain tendency was a matter of religion or society? If one believes that the tendency first came innate from our creation, and later was made explicit in revelation, was that tendency from religion or society?

On the other hand, if you believe that life happened spontaneously and that humans gradually evolved from single-cell organisms, then you have already eliminated religion as a possible source of anything, because no religion would be true, in which case everything would fall under the category of "society." (Alternatively, anyone can claim, "A god spoke to me and you should do what I say," and that would qualify as religion. In which case, I could claim that a god spoke to me, and that you should therefore believe everything I say. And then "religion" ceases to be a meaningful category, leaving us once again with only "society.")

So, as you can see, your request is not so simple, and is really just fodder for useless Internet arguments. If you want to discuss it seriously, you will have to address these matters first.


Let me further specify my request: provide a documented example of any religion (existing or disappeared) that introduced a new moral value which was not present (and documented) in the society where said religion appeared (absorbed moral value), or in societies with which said society was in contact (imported moral value). No need to go back to prehistoric periods.

This is completely orthogonal to the belief question: that is, you could perfectly believe that Jesus is the son of God, and still you will observe that all moral values introduced by Christianity were already present in the existing society.

Note: actually, to be precise, discussion with believers will always reach a point where rational discussion completely breaks down, since, by definition, humans can not understand the ways of God. At some point I will struggle to understand a situation which says the "wall is black and the wall is white", and a believer will rightly point to me that understanding this is simply over my head, and that I just need to accept it as it is.


Even easier, you can take out critical parts of substations and other electrical infrastructure with a high-powered rifle.

The world lives on the knife-edge of chaos. It's trivial to cause mass panic by driving a car into a group of people, or by a multitude of other means.

The only reason society manages to even exist is that we generally trust each other. It's the fundamental underpinning of society. Most people are generally law abiding citizens. The reason that people don't murder each other isn't because it's illegal, it's because they don't want to.

Society relies on the fact that we are generally nice people.


>it's because they don't want to.

I would argue it's because there is no financial incentive to destroy the grid. Humans are willing to make entire species (overfishing, poaching, etc...) extinct for a quick buck.


Well we are a social species: by and large we're programmed for that.


I'm genuinely surprised at this and and some of the other comments. I'm not sure why people find this a) unexpected or b) frightening. Contrary to popular belief the whole world isn't out to get "us" and we're not on the verge of imminent global societal collapse at the hands of evil foreign powers and terrorists. No more than at any other point in history, anyway.

Perhaps we all need to stop watching so much TV.


Many of these SPOFs are tolerable because attackers are easy to track down, and those points of failure are not so bad as to destroy the ability of the system to track down and punish attackers. Where things get scary are when this deterrent effect disappears:

1. The attacker might be too powerful to deter, or might be able to make a coordinated attack that would prevent their punishment. A general great-power war would bring down many of these systems in the first few hours.

2. The attacker might be able to avoid detection or identification. This is the bucket most of those security fall under - if an attacker can take advantage of these systems anonymously, there's no deterrent effect.

Cambridge Analytica is a bit of a hybrid case; it was used by powerful probably-state actors for deniable attacks.


Almost all human interactions involve trust. Political systems just exist because enough people trust in them. Same for money, juridical systems, laws, contracts, etc.


That's why people who attack trust (mainly social engineers, but other types as well) annoy me so much. Not if they are doing it because someone asked them to, but when they abuse trust and then act like it's a bug of the system and are all high and mighty that they got away with it.

Pompous social engineer blog post: "Dunkin Donuts is laughably insecure. I was able to steal lots of donuts by lying and abusing the trust of employees. Hahaha, Dunkin Donuts security sucks, what a joke. They don't even question that my story was completely fake and that I was just a good actor, what a trash company"


Could you give any example of such catastrophes? While I understand there are lots of such points of failure, relatively speaking, I personally feel the consequence of them failing is often exaggerated, and more importantly, human civilization are really good at make quick fix when it matters.


The Northeast Blackout of 2003 [0] was set off by a trees taking out a power line. It caused a local failure that increased the load in surrounding lines, tripping breakers, which increased the load in further surrounding lines, etc, cascading into a blackout over a huge chunk of North America.

[0] https://en.wikipedia.org/wiki/Northeast_blackout_of_2003


I think there's a good reason for the trust as well: mutually assured destruction.

Sure, you can knock out a power grid with seemingly trivial means. But once you do, you're just as shit out of luck as the other guys.

It's pretty much the "too big to fail" scenario. Too much of the infrastructure we've become dependent on is just not worth taking down in an attack. Sure, GPS may have a single point of failure... but GPS is kind of useful for you as well so you don't really want to knock it out. You can't afford to replace it.

It's like these systems are just sitting around saying "Fuck with me and I will burn this whole place to the fucking ground. The fucking ground"


Civilization has proven very resilient in the face of one of its hidden SPOFs being destroyed/attacked. The same is true for two and three of those SPOFs being damaged at the same time.

I'm not convinced there wouldn't be a system degradation cliff after that point of 3+ SPOFs being attacked, e.g. a GPS issue, a massive BGP hack, Tier 3 Comm. or equivalent outage, and a DNS issue--all around the same time.

That "cliff" could cause a biblical amount of damage.

I'm sure those could all be mitigated, but the idea of them failing all at once, even coincidentally, is terrifying.


Civilization pretty much requires it.

You could waste endless cycles not trusting.

Even startups that I thought were absurd ideas ... I maybe wouldn't have done it because of a lack of trust... but they worked out.


Reevaluate assumptions, indeed!

We've just had this alert from DHS on RUS hacking into our grid: https://www.technologyreview.com/the-download/611708/russian...

The preliminary R&D and tests seem to have been run in Ukraine https://www.eenews.net/special_reports/the_hack

Clearly, it's being tracked, but ...


> The longer I am alive the more I learn about how much of human civilization depends on good faith and trust.

That's one way to look at it. The other way is that it depends on incentive.

> that bringing a power plant online is a dangerous process

Not really. Power plants are connected and disconnected from the grid several times each day.

> You have to spin up the power plant and make sure that you are in phase with the grid before connecting your power output

This is done by computer in all cases, and it's incredibly fast and easy to do so. Especially considering we're only dealing with 60Hz here. This only applies to certain types of power plants, solar plants have entirely different interconnection considerations.

> There is a serious risk that a single power plant could cause systemic damage to many devices in a region's grid but for the entire history of the US

There is serious risk that a single tree branch could cause a system wide blackout for a major portion of the US. [1]

> we have just assumed that anyone with tens of millions of dollars to invest in a power plant is just too profit-driven to pull off anything like that.

Breakers and automatic protection devices respond with incredible speed and are typically controlled by an external agency operating at a State or Regional level.

> If the last few years (decades it seems) have taught me anything, it's that we have to reevaluate many of the assumptions we have been holding about reality and our peers. From the Target/Home Depot/Equifax breaches to Facebook's Cambridge Analytica fiasco, we have just been way too lucky and way too trusting.

Relative to what? Fraud and theft will always be factors in a functioning society. Is the total value extracted by newer frauds increasing faster than our global GDP?

> I never thought the world would put so much trust in a system created by and for the US armed forces.

What are the alternatives? The world putting it's trust in a commercial system? We'd just be trading one set of known issues with another.

[1]: https://en.wikipedia.org/wiki/Northeast_blackout_of_2003


> That's one way to look at it. The other way is that it depends on incentive.

The entirety of modern economic and psychological theory can be reduced to "it depends on incentives." That's utterly unhelpful.

> Not really. Power plants are connected and disconnected from the grid several times each day.

I said "bringing a power plant online." You said "connected and disconnected from the grid." They're not even remotely the same thing: the latter is a tiny step in implementing the former.

> This is done by computer in all cases, and it's incredibly fast and easy to do so. Especially considering we're only dealing with 60Hz here. This only applies to certain types of power plants, solar plants have entirely different interconnection considerations.

Uhm... what? Power flow adjustments have been "done by computers" since at least the 1970s and the frequency is only relevant in so much as it sets physical limits on how fast geographically distributed hardware can respond to changes in the system. It doesn't really matter what the frequency is, as long as everyone agrees, the system will be fine.

> There is serious risk that a single tree branch could cause a system wide blackout for a major portion of the US. [1]

Are you arguing with me or agreeing?

> Breakers and automatic protection devices respond with incredible speed and are typically controlled by an external agency operating at a State or Regional level.

No, they don't and aren't: https://www.nvc.vt.edu/lmili/docs/Mili-Risk%20of%20Cascading... - privatization has opened us up to a lot of unforeseen weaknesses.

> Relative to what? Fraud and theft will always be factors in a functioning society. Is the total value extracted by newer frauds increasing faster than our global GDP?

Relative to where we were less than a decade ago, when Facebook was nothing more than some Ivy League hook up site.

> What are the alternatives? The world putting it's trust in a commercial system? We'd just be trading one set of known issues with another.

The alternative is fucking vigilance. Vigilance of tradeoffs. Vigilance of bad faith actors. Vigilance of the legislative branch. Vigilance of our public servants.


A few good possibilities:

1. Cell sites have their own high precision clock, so they can go at least 10-20 minutes and probably longer without any difficulty.

2. The site really only needs to see a single satellite to get time synchronization if it has the almanac and ephemeris because it knows exactly where it is and how far away the satellite is. In fact, in the presence of noise, it can integrate over a long period to pull a jammed signal out from under the noise floor.

3. There are already a number of other terrestrial sources of time. TV stations have precise timing, and a defined offset to GPS time. They also have huge output power that is more difficult to jam.

4. The cell networks can synchronize with each other. If the network simply adjusts the time to be an average of neighboring cells and its own clock, they will stay in sync. It's not required for the mobile phone network to have correct absolute time, only correct time relative to other nearby network elements.


Does anyone know if a hobbyist can pull the time from TV signals like you can with an RPi/GPS-hat/etc? I'd love to have a bedside clock that pulls from TV signal for no other reason than I didn't even know that existed until now.


A quick Google struggled to find much. I did find that DVB-T has a transport stream called "System_clock_descriptor" with identifier 0x0B [1].

[1] Pg. 22 https://freeviewnz.tv/media/1216/freeview_dtt_transmission_r...


If you're in a country that still broadcasts Teletext[0] then it's available over analog or DVB-T. VCRs used to do this to set their clock automatically in Europe.

Also, if you already have a time, you can keep it using the 50/60 Hz of the electric grid (which is specifically regulated to keep cheap alarm clocks in sync) or the TV refresh rate (which was also kept in sync deliberately for clocks in the analog days, dunno about now)

[0] https://en.wikipedia.org/wiki/Teletext


See here: http://articles.latimes.com/2001/aug/23/business/fi-37278

https://en.wikipedia.org/wiki/Extended_Data_Services

It's all old stuff, but you said your interested was "I didn't even know that existed until now".


Not TV, but this has existed for radio for a long time:

https://en.wikipedia.org/wiki/Radio_clock

So yeah, it's possible to have a clock you never have to set that's always correct just by having an antenna.


The LinuxTV dvb-apps package has a utility called dvbdate that can do this.

https://www.linuxtv.org/wiki/index.php/LinuxTV_dvb-apps


Cell towers could do all those things you suggest. They don't though. They just use a GPS receiver. They have an internal TXCO (Temperature Compensated Crystal Oscillator) or similar, but they drift eventually. 3G and earlier tech was actually more resilient. It could use GPS for more accurate timing, but didn't require it.


We often use GPS as a way to synchronize time accross distances. Even Google's data centers use GPS (and an atomic clock) for synchronization - https://www.google.com/amp/s/www.theverge.com/platform/amp/2...

GPS is such a weak signal that almost anyone transmitting ground based signals on the right frequency could easily drown out GPS - and do spoofing with a little extra research. So theoretically you could spoof near a data center and mess up a lot of data powering 1000s of applications.

On top of this civilian GPS is made to be jammed and innacurate - there's a better one the military has moved onto because of this (see the m-code section: https://en.m.wikipedia.org/wiki/GPS_Block_IIIA)

So yes, relying on an easily jammed atomic clock hurtling through space seems like a bad idea... But it's kind of the best we've got right now. At least until the cost of putting your own satellite into orbit goes down.


Although the US has always fantasised about its military having a much better GPS than everybody else, and it seems technically to be in a position to arrange this, the reality is always that a $5 civilian device is available in every store and the $8000 military device is back-ordered and won't be in stock until after the war is won, so you use the civilian device even though it's theoretically worse.

"Selective Availability" was the first incarnation of this pipe dream. Civilian GPS would be deliberately corrupted by up to 100 metres and the correct offset would be transmitted separately to authorised military devices. But, see above, in practice when the US military needed GPS it found civilian devices were available while accurate military ones were not, so it reduces the induced error to zero and bought civilian kit for the Gulf War.

The M-code won't be deployed until 2022 (probably later, these things always get delayed). That's when those Block IIIA birds "go live" even though some will be in orbit for years before that.

Jamming the M-code is not really harder than jamming other codes, this is a broadcast radio signal you can easily transmit a more powerful signal yourself. The Block IIIA birds have an extra transmitter so they can increase power... but they still can't drown out even a relatively disposable local jammer.

Spoof genuinely is harder with an extra code... and this is the supposed benefit with owning any of the GNSS systems, you can keep a secret shared key that makes your system spoof proof until bad guys learn the key. But again, in practice when war breaks out you turn out not to have thousands of expensive military-only devices with the shared secret, so you rely on the civilian stuff anyway.


Well, the aviation world still has VHF omnidirectional range (VOR) navigation [1], where you can determine what direction you are to a VHF radio transmitter based on phase difference. Unfortunately, the FAA seems hell-bent on phasing them out in the USA, likely because money.

1: https://en.wikipedia.org/wiki/VHF_omnidirectional_range

2: https://www.aopa.org/news-and-media/all-news/2015/november/2...


And Non-Directional Beacons [1]. Maybe not so popular in the USA, but common around the rest of the world, and comparatively very cheap to run.

1: https://en.wikipedia.org/wiki/Non-directional_beacon


Yep, the FAA has already decommissioned most, if not all, of our NDBs. They seem very excited about making sure there's a single point of failure for all non-visual airborne navigation.


Actually gaming GPS is well within the pockets of anyone.

https://www.rtl-sdr.com/using-a-hackrf-to-spoof-gps-navigati...

The same principle is likely applicable to other standards as well, until the day they add encryption, which will probably need a lot of time and research to overcome the inevitable associated timing problems.

If doable at military level, the possible scenarios are catastrophic: country A launches say 5 test missiles, country B from nearby hidden submarine launches 5 much smaller and stealth jamming missiles. The jamming missiles approach the bigger ones then jam them into believing they're slightly off course forcing them to adjust, while in reality they're being slowly directed to country C. Of course any loss of control by ground base should be interpreted as self destruct by the missile, so it'd be near impossible to do it actually, but if other signals could be spoofed as well as positioning, then that would be a problem.


There is a well known arms race in ECM and ECCM [0]. The military (US at least) is not relying on GPS alone for this type of thing, and uses various types of jamming detection, jamming protection, and counter measures

[0] https://en.wikipedia.org/wiki/Electronic_counter-countermeas...


This is why missiles don't use GPS. (at least U.S. ones as far as I know)

They use a highly precise inertial measurement unit to track their location since launch.


They use GPS and a lot of different technique because the IMU need regular correction. But the main source of trust is the IMU. By jamming the GPS signal you can induce more drifting, but you would have to jam it for a long time to induce a very big drifting (and even them, it might be compensated by the other technique employed).


They use a combination of GPS, terrain recognition, and IMUs.


US, Russia, and China all have intependant “Global Positioning” Systems, GPS, GLONASS and BDS.

All similar in function and implementation.

The coolest part about GPS is the fact that temporal relativity is employed to establish a 3D location from accurate flying clock radios, that’s rad.


There's a relativity correction step for communication between Iridium satellites and mobiles. I always thought that was really cool.


The EU also has one in deployment (Galileo).


People do not truly understand not only the dependency on GPS as a canonical source of both position and time. Navigation and nationally productivity can totally break down if it were to disappear.

But that's an extreme case. Localized and targeted GPS spoofing is not science fiction. What's worse - the GPS spoofing can be designed to warp world geometry in particularly nefarious ways to coerce the trajectory of objects for specific purposes. It's not even that expensive, it's just a different algorithmic problem.

Those algorithms will become trivial in the future - and they will have not been tested by most (if any) of the various autonomous service providers.


Some people do understand. That's why many countries have made their own independent "GPS" systems.


More of the same easily-jammable schemes is not a real solution. But all wireless location/navigation/time-distribution mechanisms will be easily jammed. The only solution is fantastic improvements in inertial navigation devices.


Made me think of an old Phrack article, "Low Cost and Portable GPS Jammer". Worth a read!

http://phrack.org/issues/60/13.html#article


Not shocking to anyone who set up GPS systems in the early days. Or anyone who lives in a city with lots of shiny buildings. Or lives near a military facility. Or drives the Beltway around D.C. Or...


BeiDou is actually more advanced as it supports full-duplex communication, which essentially allows you to send message to the satellites.


I hope getting a location fix doesn't require actually sending anything to the satellite, as that would be a monumentally stupid design.


And then what? A.la. personal emergency beacons?


GPS Block IIIA actually does have a COSPAS SARSAT receiver on it and of course it can transmit on GPS frequencies. Today a Personal Locator Beacons doesn't think about the signals it receives from GPS other than as a source of location, but the intent is that a future COSPAS SARSAT upgrade will let the operators send a return message via GPS if they conclude you need rescuing.


Satellite based SMS would be pretty amazing for hikers/campers/etc.



This exists for at least a decade now.


lmao full-duplex. It's just the first generation of BeiDou has a auxiliary uplink channel for short messages.


AKA full-duplex


full-duplex transmission of data in two directions simultaneously in the same channel. SMS is a done via Beidou-1 satellites, and Beidou-1 don't serve as positioning at all today.

Beidou-2 is just like GPS, positioning service only, no SMS or shit.


If you're curious how GPS works, this is a surprisingly approachable guide where a guy built his own and detailed lots of the knowledge http://lea.hamradio.si/~s53mv/navsats/theory.html


FYI the 24 GPS satellites are all in Low Earth Orbit. Well within the reach of missile technology today. These will be taken out within minutes of the next war. This is why the Naval Academy as of 2 years ago teaches navigation by sextant. Was in the Army as late as 2013, and they (at least that unit) almost never let us use GPS during training (only USGS maps, protractors and compass) for this reason.


>FYI the 24 GPS satellites are all in Low Earth Orbit.

No, they're not.

LEO is an orbital period of 128 minutes or less, which for circular orbits is ~1200 miles or less [1]. GPS satellites are in 12 hour orbits ( see "Orbital Characteristics" in [1], putting them at a little more than 12,500 miles out [2].

And anyway, a satellite's altitude has little to do with how soft a target it might be. It's not simple.

That said, I'm glad training emphasizes non-GPS modalities. You never can tell when Carrington will come calling [3].

[1] https://en.wikipedia.org/wiki/Low_Earth_orbit [2] https://en.wikipedia.org/wiki/Global_Positioning_System [3] https://en.wikipedia.org/wiki/Solar_storm_of_1859


For those knowing not so much about orbital mechanics - that's about halfway to geostationary (orbit radius (semi-major axis, technically) is directly proportional to period, and GEO has by definition a 24-hour period).


There are 33 GPS satellites, and they are in a medium orbit, not LEO. Which is not to say they are invulnerable, but compared to jamming or spoofing, I think the satellites themselves are considered one of the less likely points of failure (or attack) of the system.


24 is the minimum number, 33 is the target number, there are currently 31 active, and 9 in testing/reserve some of which could be activated if need be.

(according to Wikipedia, this discussion got me to read more about it)


I'm just curious what people think about this imaginary scenario.

Let say an opponent already have satellites in space with laser weapons, could they just destroy the GPS satellites using such a tech ? Or do you guys think that this technology does not exists ?

We saw some videos in recent years of NASA laser weapons taking down planes. That's why I'm thinking about this. Maybe the distance in space would make it impossible... I have no clue.


It would still has line of sight to deal with so you would either need a bunch of them or some type of maneuverability. It would be easier to just shoot a rocket it at.

https://en.wikipedia.org/wiki/Anti-satellite_weapon


Line of sight wouldn't be an issue, range and aiming would be the problem. The GPS satellites are in a bunch of orbital planes so a weapon wouldn't try to rendezvous with each target, it would need to hit them from another orbit. The solution would be to launch the weapon in a lower orbit and just wait until each target comes within range.

If aiming a laser accurately is too tough of a challenge (probably is) then as an alternative you would need 6 weapons and launch each one in one of the 6 orbital planes that the GPS constellation uses and just have a little bit lower orbit than the GPS satellites so it would come around and catch up to each satellite but not be travelling so fast as to make accurately aiming impossible.


Lasers delivering enough energy to be useful as a weapon are limited in range by diffraction; for a satellite-launchable laser, this on the order of hundreds of kilometers.


Pure speculation but I think the X37-B spacecraft is probably some sort of satellite jammer / destroyer and possibly a refuel / service ship.


Probably not.

Its design features are:

1. Long-duration flight (low-single-digit years).

2. In very small numbers (at most one in orbit at a time).

3. Recoverability of payload.

4. Very high delta-V (i.e. can shift orbits a lot, and has been observed doing so in big jumps during deployments).

The most likely guess is a testbed for military satellite subsystems; put a camera or a radar on there, and you can get a feel for its performance at different altitudes/angles, and also bring the prototypes back down to do a teardown after the fact.


The GPS satellites have a period of half a day. This puts them in MEO.


~22000 km is far above LEO.


There’s also astral navigation (how did automatic AN computers work in the 1970s/1980s anyway? CCD and mememy tech was far more primitive, so I really want to know the technical details) - and ground-based radio beacons.


Automated celestial navigation is actually surprisingly old technology, first being pioneered in the 1950s on the snark missile. Of course at first it was extremely unreliable, with the snark flying off target so often the part of the ocean the missiles were being tested in was humorously dubbed "snark infested waters" due to all the off target missiles that sunk there. But eventually people got better and did amazing things with relatively primitive tools, and by the '60s decently successful guidance systems using the stars were common place on ICBMS.

As to technical details, here is a write up of the NAS26 astro-inertial guidance system from the '70s:

http://www.dtic.mil/dtic/tr/fulltext/u2/a090649.pdf

The navy and the air force get all the coolest toys, I tell you what.


The SR71 had impressive AN computers. Here is where you might start [0] looking. I found some lessons online [1] that might help.

[0] https://timeandnavigation.si.edu/multimedia-asset/nortronics...

[1] https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&c...


I mean, did they work at all? GPS was around in the 70's/80's, just not in any way that was useful for civilian purposes.


Once all the GPS (or similar) satellites are knocked out, uh, what are you going to use now fight the war?

On either side?

And anyways, what country has the budget to knock out twenty four satellites in quick succession?

And what if this doesn't work? I'm having a hard time thinking the US Gov. doesn't have a shadow GPS constellation up there, somewhere, but I will concede this is the most wahoo part of my meanderings...

I think knocking out GPS is a rather risky move to even try.


> what country has the budget to knock out twenty four satellites in quick succession?

The only countries between whom a war would be a globally consequential event: the United States, China, and Russia.


I understand your point, but I think your choice of words underestimates the global consequences of war.


Actually any country with a nuclear weapon should be on that list.

And that is quite a few: Israel, UK, France, India with North Korea/Iran not that far behind.


That's not enough - you also have to be able to deliver the warhead to the satellite.

It's not very easy to do.


+ Pakistan


Doesn't have to be knocked out. India developed Indian Regional Navigation Satellite System (IRNSS) because access to GPS is not guaranteed in hostile situations when its controlled by one country, as it happened to the Indian military in 1999 during the Kargil war when it was dependent on GPS and was denied access.


That's a feature, not a bug. GPS is the US-based sat. nav. system. Of course they can turn it off at will.

And of course to get around that, is to put your own sat. nav. system together.


The US military doesn't use GPS for military navigation, they use it for precisely measuring the Earth. This happens almost entirely in peacetime, so no threat to the satellites. US military navigation and guidance systems rely on INS, which is neither jammable nor spoofable, based on the GPS measurements collected in peacetime.

The US military uses very advanced and highly classified inertial navigation technology for both guidance and navigation systems pervasively. GPS was just a way to collect the data required to make inertial guidance effective. The US military has never relied on GPS for anything; the Soviets could destroy it the day it was designed, so it wasn't designed for war.


They do use GPS for military navigation, but as part of a broader suite of systems. For example, Tomahawk missiles use INS for continuous estimates, plus a combination of visual and radar terrain contour matching and GPS to correct the inertial fix. And probably a few other things they don't talk about publicly.

When they can get it, GPS reduces error, though I agree that systems are designed to be tolerant of jamming and shootdowns.


> And anyways, what country has the budget to knock out twenty four satellites in quick succession?

China and USA. Any war that they don't participate in is anyway irrelevant on the global scene.


The US Air Force has a keen interest in SpaceX with its possibility for rapid launches of reusable rockets for this and other reasons. SpaceX is hoping for less than one day turnaround with its most recent design (block 5) of its Falcon 9 rockets[1]. This design is already flying. With enough GPS satellites in storage, they could all be replaced in a week.

[1]https://spacenews.com/spacex-targeting-24-hour-turnaround-in...


There are also much simpler workarounds. Although not as precise, early cruise missiles simply used a gyroscope.

Another option would be hacking the enemie's GPS-like system. I assume we're already hard at work on that.


I imagine that the military is going to be much more effective without having to use workarounds. I doubt current munitions have extra weight dedicated to backup gyroscope navigation (could be wrong). Launching two dozen satellites has to be easier, faster, and cheaper than replacing the whole military's munitions stockpile with less effective weapons.


replying to sibling - i recall reading that ICBMs use celestial navigation.


What country? Russia or China.

They don't have to take them all out at once. Just the threat of the system going sown at any time is enough to make it unreliant.


Think of the threat to the US GPS system. To make it stick, you need to knock out most of the GPS system,

as well as the system of the US allies (EU) and if you do that, you're in hot water with those allies.

I say, good luck with that, sir.

I think 24 missiles pointed at earth targets would have more impact than some pesky satellites.


> as well as the system of the US allies (EU) and if you do that, you're in hot water with those allies.

You will already be in a lot of hot water if you're in a war with the US. The countries who have the capability of doing this have thousands of missiles. A hundred of them being used to knock out some sats is nothing.


Missile launches still involve a significant cost. Firing a missile into space is not a cheap proposition.

And again, what if it doesn't work? You can only try this one time. After that, you lose your element of surprise. Your enemy now knows the enormity of your intent to do harm. Lesson to be learned from Pearl Harbor.

Risky. Risky. Risky.


Presumably you are betting your sextant skills are better than the other guy's.


~let's have kiki~


FOAM [1] is trying to solve this. They're using a distributed network of radio beacons which offer location services using time synchronization.

https://foam.space


Every day I discover a new use case crammed into a blockchain with a sledgehammer.


While I can get behind many of the use cases for FOAM's proposed product, avoiding interference isn't one of them.

LoRa is particularly susceptible to jamming. Given the frequencies used, accidental jamming by legally operating transmitters is a very real possibility.

It also turns out that LoRaWAN is vulnerable to selective jamming, but I'm not sure whether or not FOAM is looking to make use of the LoRaWAN layer.

https://arxiv.org/abs/1712.02141


^ Just another crypto hype/scam.


These blockchain fellas and are working on an Ethereum's alternative.

https://blog.foam.space/introduction-to-proof-of-location-6b...




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