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The World Economy Runs on GPS. It Needs a Backup Plan
- Bucephalus355 8y agoFYI 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.
- DaiPlusPlus 8y agoThere’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.
- justinator 8y agoI 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.
- RyJones 8y agoThe 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-nas-14v2-astroinertial-navigation-system https://timeandnavigation.si.edu/multimedia-asset/nortronics... [1] https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=2ahUKEwjd_9zl7rvcAhWbIjQIHSSJCFQQFjAAegQIBxAC&url=http%3A%2F%2Ffer3.com%2Farc%2Fimgx%2Fmalkin-accuracy-of-astro-nav.pdf&usg=AOvVaw0VR5di0SMKMZ5tV0tCOK-q https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&c...
- j9461701 8y agoAutomated 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 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.
- Analemma_ 8y agoThere 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.
- alain_gilbert 8y agoI'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.
- speeq 8y agoPure speculation but I think the X37-B spacecraft is probably some sort of satellite jammer / destroyer and possibly a refuel / service ship.
- azernik 8y agoProbably 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.
- rhcom2 8y agoIt 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 https://en.wikipedia.org/wiki/Anti-satellite_weapon
- lloda 8y ago~22000 km is far above LEO.
- deleted 8y ago[deleted]
- starpilot 8y ago~let's have kiki~
- saagarjha 8y agoThe GPS satellites have a period of half a day. This puts them in MEO.
- justinator 8y agoOnce 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.
- dingo_bat 8y ago> 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.
- lobotryas 8y agoWhat 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.
- justinator 8y agoThink 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.
- rohit89 8y ago> 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.
- ridgeguy 8y ago>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 https://en.wikipedia.org/wiki/Low_Earth_orbit [2] https://en.wikipedia.org/wiki/Global_Positioning_System https://en.wikipedia.org/wiki/Global_Positioning_System [3] https://en.wikipedia.org/wiki/Solar_storm_of_1859 https://en.wikipedia.org/wiki/Solar_storm_of_1859
- azernik 8y agoFor 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).
- eltoozero 8y agoUS, 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.
- jpatokal 8y agoApparently 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/GLONASS https://en.wikipedia.org/wiki/Galileo_(satellite_navigation) https://en.wikipedia.org/wiki/Galileo_(satellite_navigation) https://en.wikipedia.org/wiki/BeiDou_Navigation_Satellite_System 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.
- deleted 8y ago[deleted]
- zkms 8y agoAny 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?
- NeedMoreTea 8y agoeLORAN never seems most likely now LORAN-C has been decommissioned and after 20 years of talking about it.
- thermodynthrway 8y agoThe 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
- jliptzin 8y ago
- civilitty 8y agoThe 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.
- toss1 8y agoReevaluate assumptions, indeed! We've just had this alert from DHS on RUS hacking into our grid: https://www.technologyreview.com/the-download/611708/russian-hackers-could-switch-americas-lights-off/ 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 https://www.eenews.net/special_reports/the_hack Clearly, it's being tracked, but ...
- akira2501 8y ago
- lileeyao 8y agoBeiDou is actually more advanced as it supports full-duplex communication, which essentially allows you to send message to the satellites.
- bdamm 8y agoAnd then what? A.la. personal emergency beacons?
- ObsoleteNerd 8y agoSatellite based SMS would be pretty amazing for hikers/campers/etc.
- isostatic 8y agohttps://www.globaltelesat.co.uk/isatphone-2-satellite-phone-rental https://www.globaltelesat.co.uk/isatphone-2-satellite-phone-...
- HeadsUpHigh 8y agoThis exists for at least a decade now.
- tialaramex 8y agoGPS 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.
- est 8y agolmao full-duplex. It's just the first generation of BeiDou has a auxiliary uplink channel for short messages.
- SmellyGeekBoy 8y ago
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- cjhanks 8y agoPeople 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.
- cup-of-tea 8y agoSome people do understand. That's why many countries have made their own independent "GPS" systems.
- cryptonector 8y agoMore 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.
- brian-armstrong 8y agoIf 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 http://lea.hamradio.si/~s53mv/navsats/theory.html
- shanev 8y agoFOAM [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 https://foam.space
- aw3c2 8y ago^ Just another crypto hype/scam.
- Uberphallus 8y agoEvery day I discover a new use case crammed into a blockchain with a sledgehammer.
- friesen 8y agoWhile 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 https://arxiv.org/abs/1712.02141
- cameldrv 8y agoA 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.
- ObsoleteNerd 8y agoDoes 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.
- berti 8y agoA 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_rules_3.pdf https://freeviewnz.tv/media/1216/freeview_dtt_transmission_r...
- deleted 8y ago[deleted]
- ThinkingGuy 8y agoThe LinuxTV dvb-apps package has a utility called dvbdate that can do this. https://www.linuxtv.org/wiki/index.php/LinuxTV_dvb-apps https://www.linuxtv.org/wiki/index.php/LinuxTV_dvb-apps
- 8y ago
- ryandrake 8y agoWell, 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 https://en.wikipedia.org/wiki/VHF_omnidirectional_range 2: https://www.aopa.org/news-and-media/all-news/2015/november/24/faa-begins-decommissioning-vors https://www.aopa.org/news-and-media/all-news/2015/november/2...
- perilunar 8y agoAnd 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 https://en.wikipedia.org/wiki/Non-directional_beacon
- ryandrake 8y agoYep, 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.
- hharnisch 8y agoWe 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/2012/11/26/3692392/google-spanner-atomic-clocks-GPS 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 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.
- tialaramex 8y agoAlthough 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.
- max_ 8y agoThese blockchain fellas and are working on an Ethereum's alternative. https://blog.foam.space/introduction-to-proof-of-location-6b4c77928022 https://blog.foam.space/introduction-to-proof-of-location-6b...
- sebcat 8y agoMade me think of an old Phrack article, "Low Cost and Portable GPS Jammer". Worth a read! http://phrack.org/issues/60/13.html#article http://phrack.org/issues/60/13.html#article
- squarefoot 8y agoActually gaming GPS is well within the pockets of anyone. https://www.rtl-sdr.com/using-a-hackrf-to-spoof-gps-navigation-in-cars-and-divert-drivers/ 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.
- ericpauley 8y agoThis 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.
- maeln 8y agoThey 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).
- friesen 8y agoThey use a combination of GPS, terrain recognition, and IMUs.
- zild3d 8y agoThere 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-countermeasure https://en.wikipedia.org/wiki/Electronic_counter-countermeas...
- reaperducer 8y agoNot 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...