Fun fact: Any commercial GPS unit will stop working at 1900 kph/1200mph and/or(depends on the manufacturer) an altitude of more than 18000m/59000 ft to stop them being used for trageting systems in ICBMs. This is called the COCOM limits.
I should clarify any commericial GPS unit. The GPS units on satelites and military equipmetn of the US and allies are special, these do not have this restriction for obvious reasons, but the US or the any other entity allowed to lift these restrictions keeps an eye on those projects so none will be available to the open market.
Some Guy Similarly I should clarify, that most CubeSats use indeed the same commercial off the shelf (COTS) modules as for example mobile phones. I looked it up, actually, and they do have to "hack" the limitations out of the module firmwares. That is strictly speaking violation of ITAR, but there is no way around it :D
@@fisherking7798 More than $4b per year just for deer related accidents. PA alone spends over $400m a year. en.wikipedia.org/wiki/Deer%E2%80%93vehicle_collisions
Thats nothing, when the US was still using Iowa class battleships in the 90's their operation costs in fuel, supplies and maintenance was 700k a day each and they had 2 of these, on top of dozens of carriers and hundreds of other warships.
@pyropulse at one time You also didn't know that. You didn't discovered that satellite has time dilation problem until you too read or watch something like this Don't bash people for not knowing and lead to conclusions
@pyropulse that's great But not everybody is good at physics and know this stuff This is only for hardcore enthusiast people And everybody is not hardcore and curious
Kabloosh eventually the longer peace continues in theory technological advancement will slow. Unless private companies advance technology on their own, like SpaceX
Tim W. So far technology has been getting better exponentially though, and I think that effect will overpower the longer peace. 100 years ago planes were the most incredible technological innovation, 55 years ago we tried and failed orbital rendezvous, but just 4 years later we sent men to the moon. Now we have rovers on Mars so brilliantly engineered they last far longer than they were thought to be able to, and high resolution pictures of all the major planets, and some more. In the past 100 years we accomplished incomparable leaps in science to the entirety of human history before then, so I don’t think a lack of war can slow us down now.
Even the videos about steel would confirm that. Trauma care is my thing and we use military techniques and innovations all the time from briefings and GPS to blood banks and traction splints.
As I recall... part of the reason GPS “scrambling” (called “Selective Availability” or just “SA”) was disabled was because it didn’t matter anymore. Differential GPS had been invented for civilian use. The idea was simple... the SA system causes each satellite to lie about the time by a tiny fraction ... causing ground receivers to believe your position is shifted. When you do this to all the satellites it creates a circle of probability... an area where you may be, but not a point. Someone realized that if you have a fixed point on the ground and it’s position is known to a high degree of accuracy and THEN install a GPS receiver at that point, you can simply watch the difference between the GPS-computed position vs. the true position. You can then broadcast the difference to other “Differential GPS receivers” (DGPS) and they now know their position to a high-degree of accuracy even when Selective Availability is enabled. DGPS started showing up in civilian use and it obsoleted the ability to scramble positions based on SA. If ordinary civilians can do this, then hostile governments with more funding certainly can. Selective Availability was switched off ... presumably forever.
@@hrgwea the short answer is to look it up on a sufficiently detailed map or chart of an area to establish a known position. Those maps & charts were typically originally generated by detailed surveying equipment. The next question might be: How did the charts establish accurate location data? I am not an expert on land surveying ... I have learned probably enough to be dangerous.
In the early 1990s I worked for a while on an oil field survey crew in the Middle East that used DGPS. Our GPS receiver and correction unit combined were about the size of a microwave but the accuracy was 5cm in all three axes (with 30 seconds of signals). The company were considering an update that would improve that to 2cm after just 10 seconds, the only problem was the cost of $10,000 upgrade per unit! From memory the base station had to be in position for about a month before its correction signals could be trusted. The full time surveyors said that when the first Gulf War started the US military turned on the full SA and the system would report that they were 5000m underground or similar lat/long "errors".
@@hrgwea If you leave a GPS receive running and its position is essentially fixed (continental drift being the only movement), then it's able to basically average out the position calculated from the satellites. I use a unit to do essentially this to create highly accurate drone maps.
My grandfather was one of the physicists who designed the atomic clocks on the earlier GPS satellites. His work was on satellites up to block 2R at least, maybe block 2RM. Both him and his team are brilliant physicists, scientists, and engineers who managed to calculate a lot of this with only very basic digital computers.
@@linuxbasic3399 you think one person was responsible for such device? One of my professors at university is bragging he was creating heat protecting layer of first space shuttle. He just glued few tiles together xd
There’s something odd. I had a hand held GPS unit in the 90s and its accuracy was very good: much better than 100 metres. I have no I drew how it did that. It was quite ordinary and not very expensive.
@@CartoType probably the US companies had access to DGPS, and used their cellular antennas as reference points to increase the accuracy. This can even improve gps pass the 5m limit to centimetre precision.
I was using a hand-held Garmin GPS-90 in my Cessna HawkXP in the 90s. They worked great in the air but on the ground became a bit flaky. I still have that GPS-90. 😀
Imagine 100 years ago how advanced and futuristic it'd sounded to say any person carrying a tiny chip is able to pinpoint their location down to the nearest meters anywhere on Earth.
Apparently, the Russian GPS is designed to guide automobiles to crash into each other if the driver has a dash cam and is listening to techno music on the radio
Mike Robert....hahahahahaha....hahahahahaha.....aaaawwwwhhhhhaaaawwwwwwww...AAAAWWWWWHHHAAAAWWWW HAW HAW HAW.....dude, that is frikin hilarious....I've got tears in my eyes...
Straight up denial. Flat Earth people are incredibly adept at ignoring science. Just adding a bit more science to their everyday life doesn't change that fact. They don't have to know how GPS works and they aren't interested, so long as it works.
This should be titled "History of GPS" or "How GPS works". The question raised by the title is answered in less then 5 sec. Literally: "They make it free to use because of huge "unspecified" economic benefits"
wcbuerste7 wrong, the real reason has been reveal when the European try to make their own Galileo system, US try to persuade and then later try to block/ hinder Europe develop their own system. This is because if u don't have ur own system, then US is free to close it down during war time or any other time it sees fit. Then the whole world would be totally rely on US. European saw through that and power through all the hinderance US placed on them, US really is SOME ally😑
@@bobsink624 DUDE ... Stop being a BITCH ... Just because your country cant do it doesn't mean your goverment is any better ... In fact article 13 is happening in Europe ... AMERICA WOULD NEVER
@@bobsink624 I suspect your on to something, though I think that explanation may be a bit short on scope. The wars are controlled by the oligarchy which is also the group deciding what policies are fought, and which are allowed to pass unchallenged. I suspect it's related to more direct surveillance efforts.. for example they may be able to track each device which utilizes GPS, or the satellites could house (and almost certainly do) additional surveillance and possibly even "security" equipment, and they don't want other powers to have the excuse to place similar equipment. and Alan... America so would.. there's so many instances of giant American companies controlling the government to obtain their nefarious goals, and all the American populous (myself included) can do is gawk, be indignant, and wish that the media didn't control the majority of the populous and keep them complacent sheep.
I'm currently sitting in Dublin Airport waiting to board an a330 to fly 11 hours to LA and I'm not sure if I am more excited to fly or for Vidcon itself. Can't put subtitles or the end screen in on mobile unfortunately. Will fix that asap. Be sure to check out SimScale. I approached them, not the other way around. Their platform is amazing
I like how you're on flights taking a moment to appreciate how nice everything around you are and making videos on them while we take everything for granted, keep up the awesome work :)
Some intersting technical notes here. 1. Trilateration technically requires 3 satellite in 3 dimensional space. However, 4 satellite required to pinpoint the user location because of receiver clock error. Actually rx clock error is 'solved' by some complicated computation. Therefore, in theory, synchronizing rx clock to reference time is not necessary. In reality, rx clock is steered so that approximately synchronized to reference time, but not exactly.(ns accuracy is impossible withoit atomic clock) 2. The intended scrambling known as 'selective availability' was theoretically eliminated by Differential GPS. It was one of the reason why the selective availability was removed. 3. There are a lot of considerations in order to make GPS correct. Relativity is just one of example. Speed of light is changed by going through ionosphere and troposphere. Minute movement of pole of Earth make coordinate system ambiguous. Earth rotation speed is also changed. And more...
Well GPS wouldn't work with that clock error, GPS only works because they use relativity to work out what the error is and correct for it. In real life Gold is gold coloured because of relativity and the orbit of Mercury can only be predicted accurately using relativity. And your stupidity is so massive it bends spacetime.
김도운 - Perhaps I'm wrong, but it was my impression that three satellites can locate you ambiguously in three dimensional space. You need your approximate altitude for a unique solution. If you have a signal from four or more satellites, the solution is unambiguous.
I knew a recreational sailor who was trying to sail offshore during the Gulf War. He had GPS on his boat & told me he knew if a scud missile was on it's way, because the usual 100metre GPS would go off completely for hours, then come on with absolute pinpoint accuracy for just long enough for the missile strike, then completely off again to prevent any sort of counter attack. Interesting to hear the full story about it's history in this video :)
I am very glad GPS exists, because I was told by someone my son had been seen at a known drug dealer's house, so I setup tracking on his phone without him knowing and when I saw he was there I got in the car and dragged him home.
the fact that you needed to enable a tracker in your son's phone and retrieve him from a 3rd party's place, is proof enough that you failed as a parent. good parenting would have prevented that kid from ever being near the people who sent them to that place. congratulations! now the entire world knows it.
if you need to lock your kid into a room 24/7, then you too are a bad parent. agreed, kids need to learn from their experiences.... that's why _going there to bring them home_ is _not letting them learn from the experience_ _letting them be caught and sent to prison_ is. _then_ you go to the precinct to pick them up, and shame them in front of everyone else. _that_ is letting them learn from _the experience_ they're not _experiencing_ anything if you go get them out of places before the event happens.
Nighthawk He already said his son was seen there, and if he was there once he could have been there many times. So I completely agree with what was done since the dad allowed his son to either learn from a possible one-off or do it again and deserve punishment.
I'm glad some people understand why I allowed him to do it again after I first heard instead of immediately shouting at him, because I made plenty mistakes of my own at his age. He already knew my feelings on drugs, so after I was told what he did I didn't want him to know I knew so when we were watching TV a scene of someone using cocaine came on and so I started talking to reinforce my feelings on drugs to hope it got him thinking.
It was originally intended to be that way when the military released it, but the telephone companies that owned all the cable lines needed for the early internet didn't like that idea and saw a nice cash cow.
Nothing is free. As the video said, GPS has its cost too but most people just don't realize it, same as internet. Maintaining internet connection globally is super costly, more than couple satellites.
GPS was already needed by the military for modernizing weapon systems.. Allowing others to piggy back was just a great secondary. The tax payer should not be a driver for entitled fucks who want "free" shit. That being said, if something is already around, and it doesn't detract from its primary purpose, no reason not to share. It cost money to operate an ISP.. Not everyone is willing to pay the same price for Internet. You have the freedom to pay for it yourself. Socialism makes people lazy, and the duty of the socialist government is to make sure everyone works but doesn't earn too much... That's what u can imagine
Squidgy The Internet is way more expensive that satellites could ever be. Launch a satellite once and you are done. The Internet requires a massive infrastructure to reach everyone, one that needs constant updating, repair, movement, and so on.
@@trygveevensen171 probably more on coverage and area because for me gps has always been trash on any device, sometimes it works but it's never been consistent unless I use cellular towers to help the location services.
There's been previous experiments with atomic clocks in planes (e.g flying near a mountain range with extra mass) and probably in satellites. GPS (and other GNSS's) are just an especially visible application of special/general relativity.
confirming as in we could be wrong about why it needs to be adjusted, but it could be that his theory just fits correctly over the reality, like if you times 8x4 to get the correct answer of 24 but the actually question was what is 7+17
Wow, never knew GPS had to take into account special and general relativity, I didn't think such a small distance in terms of the universe would matter.
It is my understanding that part of the reason the scrambling was later reduced was because the technology to basically "undo" the reduced accuracy was fairly easily available. If I recall, this amounted to placing base stations in certain areas where their position was fixed and known very precisely. These stations could send out a signal to local devices to help fill in the gaps that were introduced into the precision of the GPS signal.
@@drworm5007 the accuracy of early DGPS was actually greater than the military system and was the main reason they opened it to all. Also in times of war it can be reverted!
The reason the scrambling ("selective availability" or SA) went away was because during the first gulf war, the various coalition militaries (including the US) didn't have enough military GPS units but there were plenty of consumer units (and many soldiers bought their own personally). So it was felt that it was worth while to disable the SA during the war. SA was turned back on for several years after the war but after lobbying from many sectors, it was decided that the value of universal high quality GPS was much more valuable than any military value of making it less available.
I know the guy who helped invent gps and figure the calculations for time. He lives outside of Cleve, Oh. Retired NASA optical physicyst. Smartest guy I ever met, math savante (genius). 1 time I asked him whats the answer to something like 12,357 ÷ 5.923 and he figured it out in his head in less than 30 seconds. Ya freaking math genius. I remodeled most of him and his wife's home. He told me how he had security detail back in the 80s- 90s so the Russians/ Chinese didn't kidnap him for gps secrets. Good times!
he may be smart i believe you. but thats not hard to figure out for an enginneer. a bachelor degree could do that in 10-20 sec. its about 2.04 something... i did that in about 5-10 sec.. look there is a trick. let me do it propperlyy now: take 12. and imagine 5.9... as 6. 12/6 = 2. then you take the sum of the remaining. its about 450. that less then 6000. so its 2.0 right now. and 4.5 is less then 6. so add zeros (multiply by 10). and now do 45/6. thats something like 7.5... so the fast and short answer is 2.075 or in short 2.08 something. checking with the calculator. 2.0863... so its roughly true... but i believe you mean that he gave you the precise answer of 2.0863
This is a great video. The information was presented well and professionally! One thing you didn't mention is the "COCOM Limit", which is in place to disable GPS on objects traveling faster than 1,000 knots at an altitude higher than 18,000m. This way, we can have extremely accurate tracking worldwide, but we still prevent the use of long range missile networks.
Wendover Productions how about a dark one: showing Korean Air after mentioning one plane from them got shot down by the soviets, nice move RealEngineering, nice move
Strictly speaking there are workarounds these days if you don't have GPS, as there are several other position-determining systems that can be used. On the ground, phones can triangulate their position based on the signal strength of surrounding cellphone towers and their known, fixed locations. They can also use known WiFi networks in the area. I believe they actually use these to get your coarse position on startup to speed up GPS acquisition. On aircraft, there are even more backups. They have an inertial reference system (3 accelerometers and 3 gyros) that calculates position by integrating acceleration and angular velocity measurements over time, from the known starting position (departure airport). This is normally used in conjunction with the GPS as both systems complement each other, make up for one another's shortcomings. IRS tends to drift over time (because it can only calculate relative position) but is very accurate; GPS gives absolute position, but with a lower degree of accuracy than IRS. So you use GPS to correct out the drift of the IRS, and you use the IRS to interpolate your position to an accuracy beyond that which GPS is capable of alone. In case all the GPS systems on board the aircraft fail, the IRS functions as a fallback for navigation - in conjunction with old-school navigation devices like VORs, NDBs and the magnetic compass!
The reason the US made it free to use was because people were already producing equipment to work around it. I read an article in the mid 80's that said the US Coastguard had found away around it by using ground stations for position fixing to overcome the information scrambled by the military. Since the ground stations were fixed, it was possible to work out any error correction. Other commercial companies latched on to this and had begun to produce their own equipment along similar lines. I worked at Marconi at the time and we had projects in the pipeline for HMG using these ideas. When GPS became freely available, they were all cancelled.
Cool, so when the pentagon orders to shut it down you will be royally f'ed. Sames goes to Russia's GLONASS or China's BeiDou, dependence on a single system of any kind sure is comfy but wacky at the same time.
ThatSaneGuy not to mention that due to the broke dick communist tax return system, the top 50% in income pay 97% of the taxes. Poor people essentially don't pay taxes, because their tax returns are so huge.
.:Camper:. 1: Don't like your own comments 2. Enjoy some of the highest rent costs and highest general supply costs in the world. Enjoy sand and nothing but corruption. Your city is essentially a police state, the only reason crime rate is marginally lower than other cities of a similar size is because your people are too scared to even think about committing crime. Dubai is the single berry in a castle of shit, and it's not even that good. Anyway, I don't live in a city. I live on my own farm, with the freedom to do literally anything I want. A few weeks ago, I made an incendiary grenade and a rocket, and just fucking flung it.
Stefan Alexandrov yes pokemon go can take video of strategic forbiden area, of new prototypes and is a perfect spy product. Why best polemon are always in restricted area ?
I use the FPS, not the GPS. The FPS is the Flattard Positioning System. It will locate any flattard on earth to within 10 nanoplanes just by the odor coming out of their parents' basement.
@@Bullman8 Hi, go to your nearest university's geoscience department and ask them about gravimetry and maybe you can try out a gravimeter yourself. They are quite sturdy nowadays, not the thermos-in-a-foam-bottle thingys I used in mid-80s. Be curious! Do your own research! Gravity is out there, waiting to be measured! Maybe you can find an oil trap adjacent to a salt dome and drill and get rich!
The difference is flathearthers question everything but globers belive in evertbullshit because they need to convince themselfs and everybody else because they think that modern science revealed everything,and yet they dont know the smallest partical building blocks,every time they find smaller and smaller partical
GPS was originally available without scrambling, so if you captured your precise location before the scrambling began, then you could use those original coordinates to unscramble the scrambled system later for other coordinates.
From squad level radar to heat seekers that read differences in background radiation; Russian tech and the cognitive patterns it reflects are innovative and admirable. Doesn't suprise GLONAS is so precise.
I recall back in 1983 when that airliner was shot down. At first the Soviet Union stayed silent, hoping the world thought the airliner had just 'disappeared.' Then a while later an audio radio aircheck, gotten from a CIA monitoring station, played at a UN gathering, the communication between the Soviet fighter pilot and his ground commander about that airliner being shot down. It must have rattled the Soviet officials that the US had eavesdropping capabilities in a remote part of the world.
The 100m is an old accuracy estimate, as explained in the video. Today is really less than 10m, usually just 2-3m. Source : I have experience in GPS testing
I remember in the 90s, most gps handhelds had ways to circumvent the scrambled signals for increased resolution. That might also explain why they stopped scrambling...
Yeah, I heard that the US government has the authority to retract GPS services at any time, at their own discretion. I did not know, however, that so many other countries have or are going to have their own GPS systems. Makes me wonder if the need came where the US considered pulling worldwide GPS services would really have an effect. Aside from any pilots like myself that may be in the air relying on GPS for safety and ease of navigation. Which brings me to my other point. VORs are aviation navigational aids that link many major airports and locations and allow pilots to navigate over a radio, free of GPS.VORs are going out of service around the US as many pilots rely on GPS now as their sole navigating aid. This is unsafe and increases the risk of if something were to go wrong (say you lost connection, a satellite went dark, or the US pulled their GPS services) you would be stranded without traffic avoidance (unless you've already made arrangements with on-the-ground stations) or navigation aids. So please, if you ever hear someone talking about how VORs need to be put out of service, please steer them in the right direction.
Yes it would have an effect and let me tell you why. The other constellations have been developed to service only the local host's region and are not available outside. So if the US GPS went down, your phone wouldn't be able to track just because there's other constellations available. Only the US and to some extent Russia ( your device needs to have a separate GLONASS chip) provides positioning services for civilians globally. The European, Chinese, Indian and Japanese constellations only service their own region with only the European and Japanese constellation being open for full civilian use locally. The Chinese is mostly commercial and military sector use, and the Indian is Military (limited civilian later) only. Good thing the US and its taxpayers exist.
GLONASS is widely available on smartphones even today. The European Galileo will be entirely for civilian use all around the world but I think they are running in some issues currently even though the system is officially operational.
Fortunately the new block IIIF sattelites that will be replacing half of the network won't have selective availability so 10 years from now, it could get hard for the US to degrade civilian accuracy without having jammers everywhere.
CharlieMason.. mate you're unfortunately wrong.. GLONASS (Russian GPS) is available as backup with global coverage. Almost all GPS units incl. the ones in smartphones nowadays have GLONASS support
Time dilation is such a cool. We can affect how time passes based on speed and gravity. The one thing binding is all together isn’t fixed but dependent on affects we can measure.
I hate to break it to you, but cell phones take the date/time from the local cell towers (stratum 2 clocks) in order to determine the local time. If you don't believe me, put your phone in airplane mode, then enable the GPS. You won't be able to get a lock because the phone's software won't use the internal battery clock, but instead relies on the clock from the cell tower.
Agreed, however his statement was specifically about cell phones, which is why I replied like that. It's one of the reasons that cell phone manufacturers piss me off so much. I know for a fact that you can run a GPS w/o cell signal, but they design it so that it won't.
Sounds like very bad software design on your phone's operating system, they simply deactivate GPS in AP mode. Timekeeping is inherent to GPS, so it is very hard to imagine how there even could be a GPS unit without its own internal clock, separate from the phone/OS clock. Cell tower time is not even accurate enough to use for positioning. As a software engineer I've been integrating mobile phone engines into other products (for tracking industrial goods etc.) - edit: maybe it was a design decision to save power. You may have noticed that the GPS receiver is one of the most energy consuming components on your phone. That's due to the very weak signals that need to be received. So perhaps the product designer was thinking "when people put the phone in AP mode, because they are in an airplane or hospital, they usually don't really want to use it. Let's turn the GPS off so the battery does not go flat by the time they switch it back on".
Awesome video! Will you do videos about other satellite constellations? I know there isn't much information about this yet, but I really want to know why internet over satellite sucks and how SpaceX wants to change that, but needs 7500 satellites to do this.
I don't know all the reasons but I have read that SpaceX's constellation is going to be MUCH lower than the GPS orbit so they will need more to cover the area. And smaller (easier to produce satellites) will result in less powerful signals=more and an explanation for the lower orbit. I wonder if the lower orbit will make the quality of internet better??
Apace Sucks, because the satelites does not exist! They told to us that in space orbiting 37000 satelites but some places on the world even dont have GPS signal! How is that even posible! hahah! Google for it! Use your damn brain!
A bit late, but think about it. Satellites tend to be about 1-2x the size of a car not including the solar panels at full extension. Now that's big, but not nearly as big as the racks upon racks of state of the art servers that sit on top of the junctions in the fiber optic network that comprises the internet, not to mention the cooling the building itself provides form the air. Satellites have to deal with the heat in other ways. There is only so much computing power you can cram into a satellite along with the engine, batteries, transformer, and active cooling system, not to mention it has to be energy efficient, and also has computing power restricted by the components having to be radiation hardened to some degree to resist possible bit flipping corrupting information. This satellite is also at least 1000km above the surface of the earth, possibly 20,000km up in geostationary orbit, and has to receive an uplink from ground stations, provide its own uplink to a base station, provide downlinks to dozens maybe hundreds of said ground stations stations all on its own and in the middle of all of this, its trying to supply a steady, usable internet connection. Not exactly easy when you have the data center volume equivalent of a flaming shoebox to work with
Man it blows my mind that technology used in our everyday life has to account for a difference in passage of time for us in comparison to it. The way something like that is just so casually said and accepted makes me feel like Im in Star Trek.
The SR-71 had an "R2-D2" behind the RIO pilot that served as a GPS unit for the SR-71. There was a small circular window behind the RIO pilot that triangulated the stars while the plane was taxiing and gave the GPS of the plane. If it was cloudy, the plane had to be above the cloud bank to know its GPS.
Missed one important thing. 1 satelates makes a shell 2 satelates makes a curve 3 satelites makes a point (rather 2.. but one is far out in space) So why do you need 4 satellites. The 4:th is to send reference time
more signals = increased probability of being accurate. The each satellite signal acts as a check on the box the other 3 draw, allowing the system to be that much more accurate. The more signals a receiver can process against each other at once, the better accuracy you'll get.
Despite the original post's bad spelling, he is correct. 3 satellites create 3 spheres which give you 2 points. But you have one more sphere in the equation: Earth. In the combination with that you know a specific point. But the problem is that you need atomic clock time accuracy to make this computation and that is provided by the fourth satellite. I hope this helped you understand. I studied GIS in university.
AFAIK, GPS doesn't even broadcast the position of the satellite, just the accurate time. That allows you to calculate the position with 4 signals, even if you don't have the accurate time yourself (the vid was wrong on that your phone needed the time)
Clifford Kintanar Wrong. The GPS always broadcast the ephemerical data, you can calculate and predict the satelite position based on this data and time of positioning.
the *commercial* aviation industry does not use it for navigation and collision avoidance, as far as I know (aero engineer here with not much experience in air traffic) navigation relies on radio beacons on the ground, and the Traffic Alert and Collision Avoidance System works via radio signals emitted and received by every plane. But, there are plans indeed to integrate GNSS (GPS) into aviation navigation in the near future!
By making it "free" but still control it's use, they can put certain limitations and restrictions on it. Having the ability to turn the system off or cause random offset/shifts in the calculated gps coordinates if needed. Their biggest fear is a foreign drone or attacker using a gps system to target major targets in the US.
it also limited the speed of competing space programs by reducing their need to launch large numbers of gps satellites into space, in turn delaying the advancement of missiles and other rocket technologies that could deliver nuclear warheads
Actually only the 'C/A code' is available, which is a very small part of the total GPS signal. It is access to this code that provides the 'Standard Positioning Service'. The really valuable access is to the 'P code' (or 'M code') which provides the 'Precise Positioning Service' which is used by the US military.
You missed a lot of funny and important bits. Like why they REALLY stopped scrambling the signal: there was not enough military units available at the time of Desert Storm, so they had to buy civilian units and thus stopped scrambling. Or how in fact the receiver 'decodes' the signal (it does not, it just matches the pattern received to a set of patterns in memory). Or why do you in fact need four satellites (your explanation is superfluous). Also, the phones DO NOT get time from the satellites. They could, but they do not. Also, GLONASS is hardly operational, there just aren't any non-GPS receivers in the world (apart from Russian military ones - presumably). Finally, a lot of countries have their own GPS-augmentation systems (SBAS). EGNOS, WAAS, to name a few.
He already said that other countries have their own systems. It's only funny in your sick mind. It's amazing you even have 5 likes; man people are desperate to hear US hate
Interestingly, Indian Positioning System🇮🇳 IRNSS: NavIC has resolution of 1 metre! Still we use the US' GPS. However, Qualcomm Snapdragon will introduce NavIC very soon.
NavIC is only for Indians It's useless for other parts of the world Its main essence is to locate Pakistan military moments in Kashmir And yes it's more accurate than GPS
+MegaMGstudios You confused the word "theory" with "hypothesis". A theory is a long, formal scientific explanation of a certain thing/things *and it has evidence to disprove anything that contradicts the theory.* It also has a law/laws (a law is a rule that can be used to predict things) and predictions (by using the law). On the other hand, a hypothesis is an explanation but is without evidence, a law/laws, nor predictions.
I bought a Garmin GPS in the mid 90's for my workboat it was able to help me tru the fog in narragansett bay no problem. I remember the accuracy was +or- 50ft depending on how many satellites could be locked onto.
Doubtless developed for missile guidance, but I suspect it's not 'free' - I assume that GPS device manufacturers have to pay a licence fee to USA. Nonetheless, it's a fantastic development.
Google has $80 billion cash. The cost to build and deploy 24 GPS satellites would be a few billion, tops. They could probably charge $10 per device for consumers (and a lot more for business entities) if there were no alternatives.
its more about having a spaceship to launch it and able to get 24 satellites into orbit. Where are they going to launch their rockets if the usa says they cant launch them inside our country?
Somewhere on the other 98% of the globe. Maybe the the US could sabotage or shoot down the launch, but Google knows the dirty secrets of everyone who might make that decision.
well i guess it would be possible... but google isn't really established enough anywhere else to have resources to start a fucking space agency and still have it somewhat cost effective.
His explanation for how time is used by the receiver is simplified to the point of being wrong. The receiver doesn't need to know the time to get the position. Normally you would need three satellites to calculate your position in three dimensions. But if you don't know the time you can solve for it as well. That's why you need four satellites. Because you solve for four unknowns: Latitude, Longitude, Height and Time. Interestingly, if you know your height (for example if you're a ship on the ocean) you can solve for Latitude, Longitude and Time with only three satellites. n practice though, you use as many satellites as you can to get a better result. Why The US Military Made GPS Free-To-Use? Because a Korean passenger plane was shot down by the Soviets in the 1980s due to a navigation error. After that the US made GPS free to use for everyone.
But the receiver at least need to know a rough estimate of the time right? Otherwise, how would it be able to sync up its pseudocode with the satellites' code?
Jonas Eriksson Interestingly, the satellites doesn't actually broadcast their position (since they move it would be wrong by the time the receiver gets it). Instead they send parameters (called ephemeris) that can be used to calculate the position at any point in time (or at least for the next couple of hours). Another thing they send out is the clock error, how far ahead or behind that particular satellites clock is to the real time. All those parameters are updated a couple of times a day from control stations on the ground.
Jay Cadilak Umm.. what? I have never said that. Stop making up bullshit to discredit me, the least you can do is provide a counter argument....fucking idiot
The effects of gravity influence time dilation more, so wouldn’t the satellite’s clock need to tick slower than at the surface of earth in order for them to be in sync?
As an object experiments more gravity, time will pass slower, this effect also applies to fast moving objects, which is the case for gps satellites, so overall, time passes faster on earth than on those satellites, though, if they orbited at say, 100 times the speed, their clocks would definitely need to tick slower than on earth.
Einstein’s theory of General Relativity is all about this, but you first need to understand his special theory or relativity first. Very few people can follow them, but if you can, then you’ll get it.
This is an easy one to answer. If we assume that you use your phone to tell the time then, if you drop your phone, it will fall and hit the ground under the influence of gravity and smash into pieces - which will stop time. A clear demonstration of the way gravity affects time.
The first generation of public GPS had a built-in error so that they couldn’t be used as a weapon. But smart companies set up vans at known and accurate locations that radioed the error direction and amount to survey crews in the field. You see the error was the same for a certain amount of time. The survey crew received the error data and corrected their location. This caused the government to give up and simply send accurate locations on the GPS system. The military GPS also allowed cruise missiles to quit looking straight down and comparing the landscape to maps pre-loaded into the computer to go instead to high altitudes and then drop from the sky and accurately hit their targets.
America didn't give anybody anything. The GPS system was built and is maintained by USA taxpayers. It's one of the few tecchie things that's worth a shit.
@@garychristenson6370 The United States taxpayers are the ones giving because they have voluntarily chosen to give access to everyone else. They are voluntarily giving access to everyone because there has never been mass opposition of free worldwide GPS.
I am sorry to say, that there is an error in your video: If you use 3 satellites for positioning it is possible to calculate the position (due to geometry, 2 Points could be calculated, one on the earths surface and one deep in space). One of these is not viable and can be ruled out... guess which one. So why do you need the 4th satellite? The answer is simple (well actually its math so...). If you use only 3 satellites you would need an exact clock (like the one build into the satellites). If 4 satellites are used you only need the time differences between the time broadcasted by the satellites (and a very basic clock provided by your phone, and a way to look up the positioning of the satellites based on their broadcasted time). So in no way is the satellite "setting" your gps phone time in any way.
top kek :Einstein's principle of relativity is a key element for GPS to work (perfectly explained in the video). Actually I am baffled how you come to this conclusion based on my comment.
m_endres Without the 4th satellite, you will also often have inaccurate altitude measurements, and the second location may not be in deep space, it sometimes ends up somewhere not on the surface of Earth, but near enough to Earth that it's technically possible if you're in a plane for example. The GPS just assumes you're not flying or on a mountain. The 4th satellite selects the final of the two locations though and ensures an accurate altitude as well as more accurate position in general making the service more usable.
I'm still thankful he didnt go like "omg this is so hard I know you wont understand how to do this math viewer" like all the rest of the youtubers. Like dude your plugging in numbers into an algrebra equation, almost all of us can do this. At max your doing some light derivatives which I get not everyone has done calculus but it still isnt the most overwhelming thing in the world.
TrollBuster Most of their ideas are religion based. Because their holy book says a man cannot leave the Earth due to the magical Firmament they must assume anything to do with space is fake, ie pics of the Earth from space ect..must be fake! That leads them to decide that any kind of space orbiting sats cannot be real and the whole idea must be fake also. Imagine if you 100% believe in god and science fact is proving otherwise......unless you change your way of thinking you MUST denounce everything else, otherwise your whole faith goes out the window. Conspiracy theorists like to think they are in a little club and they know stuff no one else does.....it makes them feel special. We know they are special...but not in the way they think.
+Chad Owen _"true that gps is a ground base system no satilites lmfao"_ +Stewart Goodwin _"radio towers are on the ground globey"_ So you guys think it is somehow possible to multilaterate an accurate position fix, with altitude, using signals all coming from elevation angles just a degree or two above horizontal (as would be the case for any terrestrial radio towers more than a few meters away)? You could make billions licensing that technology - accurate positioning including altitude data without the massively extreme costs of launching and maintaining a large constellation of satellites would be a very lucrative business.
Fun fact: Any commercial GPS unit will stop working at 1900 kph/1200mph and/or(depends on the manufacturer) an altitude of more than 18000m/59000 ft to stop them being used for trageting systems in ICBMs. This is called the COCOM limits.
Some Guy I didn't know that, thanks
Some Guy And yet most CubeSats use those same regular off-the-self GPS modules just fine. They travel both higher and faster than the limits.
I should clarify any commericial GPS unit. The GPS units on satelites and military equipmetn of the US and allies are special, these do not have this restriction for obvious reasons, but the US or the any other entity allowed to lift these restrictions keeps an eye on those projects so none will be available to the open market.
Some Guy Similarly I should clarify, that most CubeSats use indeed the same commercial off the shelf (COTS) modules as for example mobile phones. I looked it up, actually, and they do have to "hack" the limitations out of the module firmwares. That is strictly speaking violation of ITAR, but there is no way around it :D
I guess it's just a case of reprogramming the FPGA to remove the limits.
"2 million dollars"
me: huh that sounds cheaper than I thought it would be
"... a day"
me: oh
@Hernando Malinche 730 and a half million dollars a year from deer???
@@fisherking7798 More than $4b per year just for deer related accidents. PA alone spends over $400m a year.
en.wikipedia.org/wiki/Deer%E2%80%93vehicle_collisions
This is a drop in the pool to the economic benefits it has. GPS is cheap, that's why your toaster has one.
Thats nothing, when the US was still using Iowa class battleships in the 90's their operation costs in fuel, supplies and maintenance was 700k a day each and they had 2 of these, on top of dozens of carriers and hundreds of other warships.
In regards to FB, GPS, etc... If you ain't paying for the product, YOU are the product
I never thought a satelite would have to consider time dilation, props to the engineers..
@pyropulse at one time
You also didn't know that.
You didn't discovered that satellite has time dilation problem until you too read or watch something like this
Don't bash people for not knowing and lead to conclusions
@pyropulse that's great
But not everybody is good at physics and know this stuff
This is only for hardcore enthusiast people
And everybody is not hardcore and curious
pyropulse you’re a wanker mate
@pyropulse Mate, stop being a twonk.
@pyropulse shut up nerd
A lot of innovation came out of military necessity.
Kabloosh a lot also came from Islamic innovations :)
Kabloosh eventually the longer peace continues in theory technological advancement will slow. Unless private companies advance technology on their own, like SpaceX
@@zackjandali yeah 2000 years ago but nothing in the last 500 years
Tim W. So far technology has been getting better exponentially though, and I think that effect will overpower the longer peace. 100 years ago planes were the most incredible technological innovation, 55 years ago we tried and failed orbital rendezvous, but just 4 years later we sent men to the moon. Now we have rovers on Mars so brilliantly engineered they last far longer than they were thought to be able to, and high resolution pictures of all the major planets, and some more. In the past 100 years we accomplished incomparable leaps in science to the entirety of human history before then, so I don’t think a lack of war can slow us down now.
Even the videos about steel would confirm that. Trauma care is my thing and we use military techniques and innovations all the time from briefings and GPS to blood banks and traction splints.
As I recall... part of the reason GPS “scrambling” (called “Selective Availability” or just “SA”) was disabled was because it didn’t matter anymore. Differential GPS had been invented for civilian use. The idea was simple... the SA system causes each satellite to lie about the time by a tiny fraction ... causing ground receivers to believe your position is shifted. When you do this to all the satellites it creates a circle of probability... an area where you may be, but not a point. Someone realized that if you have a fixed point on the ground and it’s position is known to a high degree of accuracy and THEN install a GPS receiver at that point, you can simply watch the difference between the GPS-computed position vs. the true position. You can then broadcast the difference to other “Differential GPS receivers” (DGPS) and they now know their position to a high-degree of accuracy even when Selective Availability is enabled. DGPS started showing up in civilian use and it obsoleted the ability to scramble positions based on SA. If ordinary civilians can do this, then hostile governments with more funding certainly can. Selective Availability was switched off ... presumably forever.
A question if I may: How do you determine the precise coordinates of the fixed point?
@@hrgwea the short answer is to look it up on a sufficiently detailed map or chart of an area to establish a known position. Those maps & charts were typically originally generated by detailed surveying equipment.
The next question might be: How did the charts establish accurate location data?
I am not an expert on land surveying ... I have learned probably enough to be dangerous.
In the early 1990s I worked for a while on an oil field survey crew in the Middle East that used DGPS. Our GPS receiver and correction unit combined were about the size of a microwave but the accuracy was 5cm in all three axes (with 30 seconds of signals). The company were considering an update that would improve that to 2cm after just 10 seconds, the only problem was the cost of $10,000 upgrade per unit!
From memory the base station had to be in position for about a month before its correction signals could be trusted.
The full time surveyors said that when the first Gulf War started the US military turned on the full SA and the system would report that they were 5000m underground or similar lat/long "errors".
@@hrgwea If you leave a GPS receive running and its position is essentially fixed (continental drift being the only movement), then it's able to basically average out the position calculated from the satellites. I use a unit to do essentially this to create highly accurate drone maps.
@@bobwightman1054 Heard that figure from local farmer technicians too: 2 cm Accuracy due to the DGPS.
My grandfather was one of the physicists who designed the atomic clocks on the earlier GPS satellites. His work was on satellites up to block 2R at least, maybe block 2RM. Both him and his team are brilliant physicists, scientists, and engineers who managed to calculate a lot of this with only very basic digital computers.
No he wasn’t
yeah a name of such a person would be mentioned in the original comment.
@@linuxbasic3399 you think one person was responsible for such device? One of my professors at university is bragging he was creating heat protecting layer of first space shuttle. He just glued few tiles together xd
@@JohnSmith-uf7ci oh you 🥰
@john deere yooo, ive heard of docor deere, thats crazy.
I remember using a hand-held GPS before 2000, the scrambling was...less than ideal.
You could go for a hike in a small park and literally get lost.
There’s something odd. I had a hand held GPS unit in the 90s and its accuracy was very good: much better than 100 metres. I have no I drew how it did that. It was quite ordinary and not very expensive.
@@CartoType probably the US companies had access to DGPS, and used their cellular antennas as reference points to increase the accuracy. This can even improve gps pass the 5m limit to centimetre precision.
I was using a hand-held Garmin GPS-90 in my Cessna HawkXP in the 90s. They worked great in the air but on the ground became a bit flaky. I still have that GPS-90. 😀
It got me to the car park which was mostly enough.
Imagine 100 years ago how advanced and futuristic it'd sounded to say any person carrying a tiny chip is able to pinpoint their location down to the nearest meters anywhere on Earth.
100 years? I'm 65 and would have shelled out a lot for that when I was younger a kid
I'd say that doesn't sound advanced and futuristic, but rather, terrifying.
@@captainflappinjacks597 if you dont think it sounds advanced you clearly dont understand it very well
@@justinc2633 I was alluding to the Mark of the Beast
Apparently, the Russian GPS is designed to guide automobiles to crash into each other if the driver has a dash cam and is listening to techno music on the radio
Mike Roberti lmao for real those Russian car crash compilations are the best
only works on box Ladas
Mike Robert....hahahahahaha....hahahahahaha.....aaaawwwwhhhhhaaaawwwwwwww...AAAAWWWWWHHHAAAAWWWW HAW HAW HAW.....dude, that is frikin hilarious....I've got tears in my eyes...
Mike Roberti those videos are like half of the internet
In Russia, Car guides GPS.
How do satellites work for flat earthers?
Satellites are probably a conspiracy theory made up by the lizard people. Something like that.
I think they are whether balloons or something.
It's just the light of Venus reflecting off swamp gas, or something
They're bending the rays with tinfoil.
Straight up denial. Flat Earth people are incredibly adept at ignoring science. Just adding a bit more science to their everyday life doesn't change that fact. They don't have to know how GPS works and they aren't interested, so long as it works.
I think this is the best kind of product placement, because it fits your channel, is interesting and you seem to really like it yourself
qwert zuiopü yeap I approached them. SimScale is making a valuable engineering tool affordable, gotta love that
Real Engineering ... I was glad to hear about the tool. well done video, and good ad as well. :)
hätte nie gedacht das ich dich nach dem dimensionsloch nochmal wiederfinde
hätte nie gedacht das ich dich nach dem dimensionsloch nochmal wiederfinde
hätte nie gedacht das ich dich nach dem dimensionsloch nochmal wiederfinde
This should be titled "History of GPS" or "How GPS works".
The question raised by the title is answered in less then 5 sec. Literally: "They make it free to use because of huge "unspecified" economic benefits"
Agreed, I was a bit disappointed as well. But maybe it really was that simple of an explanation.
Yea, me too
wcbuerste7 wrong, the real reason has been reveal when the European try to make their own Galileo system, US try to persuade and then later try to block/ hinder Europe develop their own system. This is because if u don't have ur own system, then US is free to close it down during war time or any other time it sees fit. Then the whole world would be totally rely on US. European saw through that and power through all the hinderance US placed on them, US really is SOME ally😑
@@bobsink624 DUDE ... Stop being a BITCH ... Just because your country cant do it doesn't mean your goverment is any better ... In fact article 13 is happening in Europe ... AMERICA WOULD NEVER
@@bobsink624 I suspect your on to something, though I think that explanation may be a bit short on scope. The wars are controlled by the oligarchy which is also the group deciding what policies are fought, and which are allowed to pass unchallenged.
I suspect it's related to more direct surveillance efforts.. for example they may be able to track each device which utilizes GPS, or the satellites could house (and almost certainly do) additional surveillance and possibly even "security" equipment, and they don't want other powers to have the excuse to place similar equipment.
and Alan... America so would.. there's so many instances of giant American companies controlling the government to obtain their nefarious goals, and all the American populous (myself included) can do is gawk, be indignant, and wish that the media didn't control the majority of the populous and keep them complacent sheep.
Well, that was fantastic.
umm....hi.........*insert random joke here*
your fantastic!
exurb1a hi mom
Sure it was!!
simply seeing this turtle makes me question my existence
I'm currently sitting in Dublin Airport waiting to board an a330 to fly 11 hours to LA and I'm not sure if I am more excited to fly or for Vidcon itself. Can't put subtitles or the end screen in on mobile unfortunately. Will fix that asap. Be sure to check out SimScale. I approached them, not the other way around. Their platform is amazing
I like how you're on flights taking a moment to appreciate how nice everything around you are and making videos on them while we take everything for granted, keep up the awesome work :)
Not a 787, eh? ;) Have fun at Vidcon...
Critical Eats Japan unfortunately not. My favourite plane
Real Engineering yop Dublin!
did you got to Dublin institute of technology?
Some intersting technical notes here.
1. Trilateration technically requires 3 satellite in 3 dimensional space. However, 4 satellite required to pinpoint the user location because of receiver clock error. Actually rx clock error is 'solved' by some complicated computation. Therefore, in theory, synchronizing rx clock to reference time is not necessary. In reality, rx clock is steered so that approximately synchronized to reference time, but not exactly.(ns accuracy is impossible withoit atomic clock)
2. The intended scrambling known as 'selective availability' was theoretically eliminated by Differential GPS. It was one of the reason why the selective availability was removed.
3. There are a lot of considerations in order to make GPS correct. Relativity is just one of example. Speed of light is changed by going through ionosphere and troposphere. Minute movement of pole of Earth make coordinate system ambiguous. Earth rotation speed is also changed. And more...
You do not understand relativity.
Well someone didn't took his science classes seriously.
Well GPS wouldn't work with that clock error, GPS only works because they use relativity to work out what the error is and correct for it. In real life Gold is gold coloured because of relativity and the orbit of Mercury can only be predicted accurately using relativity. And your stupidity is so massive it bends spacetime.
You do not understand relativity. Please acquaint yourself with the works of Messrs Dunning and Kruger.
김도운 - Perhaps I'm wrong, but it was my impression that three satellites can locate you ambiguously in three dimensional space. You need your approximate altitude for a unique solution. If you have a signal from four or more satellites, the solution is unambiguous.
Thanks to all those engineer blokes that made this stuff happen. Thanks USA!
What about the sheilas?
@@thedownunderverse and thanks to all those engineer blokes, mothers and the lady that made the sandwiches(ha HA)
@@rods6405 haha
I knew a recreational sailor who was trying to sail offshore during the Gulf War. He had GPS on his boat & told me he knew if a scud missile was on it's way, because the usual 100metre GPS would go off completely for hours, then come on with absolute pinpoint accuracy for just long enough for the missile strike, then completely off again to prevent any sort of counter attack. Interesting to hear the full story about it's history in this video :)
Thats really cool wtf
Scuds belonged to the other side of the Gulf War
I am very glad GPS exists, because I was told by someone my son had been seen at a known drug dealer's house, so I setup tracking on his phone without him knowing and when I saw he was there I got in the car and dragged him home.
why drag your son home if he was already home?
the fact that you needed to enable a tracker in your son's phone and retrieve him from a 3rd party's place, is proof enough that you failed as a parent.
good parenting would have prevented that kid from ever being near the people who sent them to that place.
congratulations! now the entire world knows it.
if you need to lock your kid into a room 24/7, then you too are a bad parent.
agreed, kids need to learn from their experiences.... that's why _going there to bring them home_ is _not letting them learn from the experience_
_letting them be caught and sent to prison_ is.
_then_ you go to the precinct to pick them up, and shame them in front of everyone else.
_that_ is letting them learn from _the experience_
they're not _experiencing_ anything if you go get them out of places before the event happens.
Nighthawk He already said his son was seen there, and if he was there once he could have been there many times.
So I completely agree with what was done since the dad allowed his son to either learn from a possible one-off or do it again and deserve punishment.
I'm glad some people understand why I allowed him to do it again after I first heard instead of immediately shouting at him, because I made plenty mistakes of my own at his age.
He already knew my feelings on drugs, so after I was told what he did I didn't want him to know I knew so when we were watching TV a scene of someone using cocaine came on and so I started talking to reinforce my feelings on drugs to hope it got him thinking.
if free global GPS has been useful for economy and individuals, imagine how beneficial free global Internet would be.
It was originally intended to be that way when the military released it, but the telephone companies that owned all the cable lines needed for the early internet didn't like that idea and saw a nice cash cow.
Nothing is free. As the video said, GPS has its cost too but most people just don't realize it, same as internet. Maintaining internet connection globally is super costly, more than couple satellites.
Compared to what it used to cost to move data around, the difference between what the Internet costs and free is barely measurable.
GPS was already needed by the military for modernizing weapon systems.. Allowing others to piggy back was just a great secondary. The tax payer should not be a driver for entitled fucks who want "free" shit. That being said, if something is already around, and it doesn't detract from its primary purpose, no reason not to share.
It cost money to operate an ISP.. Not everyone is willing to pay the same price for Internet. You have the freedom to pay for it yourself. Socialism makes people lazy, and the duty of the socialist government is to make sure everyone works but doesn't earn too much... That's what u can imagine
Squidgy The Internet is way more expensive that satellites could ever be. Launch a satellite once and you are done. The Internet requires a massive infrastructure to reach everyone, one that needs constant updating, repair, movement, and so on.
And yet Google Maps still can't figure out that I'm not in the ocean
Im not jotaro, im on land google!!
Your thinking Apple Maps
The GPS on my phone is accurate down to a few meters, guess the accuracy varies by device, coverage and area
@@trygveevensen171 probably more on coverage and area because for me gps has always been trash on any device, sometimes it works but it's never been consistent unless I use cellular towers to help the location services.
haha....wait WHAT?
I love how GPS proves Einstein's special and general relativity true.
There's been previous experiments with atomic clocks in planes (e.g flying near a mountain range with extra mass) and probably in satellites. GPS (and other GNSS's) are just an especially visible application of special/general relativity.
Will, by not being able to disprove a theory, you're actually proving it.
Alter is right on this one;you need to understand why the theory is a THEORY.
confirming as in we could be wrong about why it needs to be adjusted, but it could be that his theory just fits correctly over the reality, like if you times 8x4 to get the correct answer of 24 but the actually question was what is 7+17
@speedy.....might want to recheck your math there, slick.
Wow, never knew GPS had to take into account special and general relativity, I didn't think such a small distance in terms of the universe would matter.
“And that is why you fail”
Not distance but speed.
@@erhan1255 Right, that and gravitational force (yes, I know that's not strictly correct -- I mean gravity, anyway).
@@Jjmartin1530 the only fail here is your worthless comment
It is my understanding that part of the reason the scrambling was later reduced was because the technology to basically "undo" the reduced accuracy was fairly easily available. If I recall, this amounted to placing base stations in certain areas where their position was fixed and known very precisely. These stations could send out a signal to local devices to help fill in the gaps that were introduced into the precision of the GPS signal.
This is called Differential GPS (or DGPS) and is still used by surveyors and equipment operators to get accuracy within centimetres.
@@drworm5007 the accuracy of early DGPS was actually greater than the military system and was the main reason they opened it to all. Also in times of war it can be reverted!
The reason the scrambling ("selective availability" or SA) went away was because during the first gulf war, the various coalition militaries (including the US) didn't have enough military GPS units but there were plenty of consumer units (and many soldiers bought their own personally). So it was felt that it was worth while to disable the SA during the war. SA was turned back on for several years after the war but after lobbying from many sectors, it was decided that the value of universal high quality GPS was much more valuable than any military value of making it less available.
I know the guy who helped invent gps and figure the calculations for time. He lives outside of Cleve, Oh. Retired NASA optical physicyst. Smartest guy I ever met, math savante (genius). 1 time I asked him whats the answer to something like 12,357 ÷ 5.923 and he figured it out in his head in less than 30 seconds. Ya freaking math genius. I remodeled most of him and his wife's home. He told me how he had security detail back in the 80s- 90s so the Russians/ Chinese didn't kidnap him for gps secrets. Good times!
I have a Friend from Persia who would be glad if you could be a little more specific about his address.
M K why !
@@MK-vh9wz lol
😂
he may be smart i believe you. but thats not hard to figure out for an enginneer. a bachelor degree could do that in 10-20 sec. its about 2.04 something... i did that in about 5-10 sec.. look there is a trick. let me do it propperlyy now: take 12. and imagine 5.9... as 6. 12/6 = 2. then you take the sum of the remaining. its about 450. that less then 6000. so its 2.0 right now. and 4.5 is less then 6. so add zeros (multiply by 10). and now do 45/6. thats something like 7.5... so the fast and short answer is 2.075 or in short 2.08 something. checking with the calculator. 2.0863... so its roughly true... but i believe you mean that he gave you the precise answer of 2.0863
This is a great video. The information was presented well and professionally! One thing you didn't mention is the "COCOM Limit", which is in place to disable GPS on objects traveling faster than 1,000 knots at an altitude higher than 18,000m. This way, we can have extremely accurate tracking worldwide, but we still prevent the use of long range missile networks.
I can't think of funny comments anymore to get top comment on your videos.
Well shit
PUSH!
Get this guy up there.
Wendover Productions how about a dark one: showing Korean Air after mentioning one plane from them got shot down by the soviets, nice move RealEngineering, nice move
lets make it happen anyway
Wendover Productions anymore?
Strictly speaking there are workarounds these days if you don't have GPS, as there are several other position-determining systems that can be used. On the ground, phones can triangulate their position based on the signal strength of surrounding cellphone towers and their known, fixed locations. They can also use known WiFi networks in the area. I believe they actually use these to get your coarse position on startup to speed up GPS acquisition.
On aircraft, there are even more backups. They have an inertial reference system (3 accelerometers and 3 gyros) that calculates position by integrating acceleration and angular velocity measurements over time, from the known starting position (departure airport). This is normally used in conjunction with the GPS as both systems complement each other, make up for one another's shortcomings. IRS tends to drift over time (because it can only calculate relative position) but is very accurate; GPS gives absolute position, but with a lower degree of accuracy than IRS. So you use GPS to correct out the drift of the IRS, and you use the IRS to interpolate your position to an accuracy beyond that which GPS is capable of alone. In case all the GPS systems on board the aircraft fail, the IRS functions as a fallback for navigation - in conjunction with old-school navigation devices like VORs, NDBs and the magnetic compass!
for the average Joe out there: no, the Internal Revenue Service, does not drift over time, it's there and it'll always be there!
Yes, and those methods are incredibly inaccurate.
(Radio signals)
DGPS which is effective within ~10cm of your X, Y, Z location.
Sherlock MacGyver Exactly. TBH those “alternatives” are laughable.
The boat at 6:14 tragically sank on the 31st December 2019 with the loss of 5 lives
Source?
EliteNK, google it’s name
Was on deadliest catch recently showing the reactions of the crew who were fishing when the scandies rose went down.
2019 saved them from 2020
ahmed4363, 1914-1990 would disagree
The reason the US made it free to use was because people were already producing equipment to work around it. I read an article in the mid 80's that said the US Coastguard had found away around it by using ground stations for position fixing to overcome the information scrambled by the military. Since the ground stations were fixed, it was possible to work out any error correction. Other commercial companies latched on to this and had begun to produce their own equipment along similar lines. I worked at Marconi at the time and we had projects in the pipeline for HMG using these ideas. When GPS became freely available, they were all cancelled.
I think the technical term is "differential GPS".
Everyone who liked this dumpster fire of a comment is an imbecile
Yes, this is true. It didn't allow Indian and Chinese government to use it, so they have their own systems.
Cool, so when the pentagon orders to shut it down you will be royally f'ed. Sames goes to Russia's GLONASS or China's BeiDou, dependence on a single system of any kind sure is comfy but wacky at the same time.
@@ritwikreddy5670 but we indian people use gps the government system is for government only!! Not for whole world for free
we pay two million a day? worth it.
thanks btw
it's free in a communist way, everyone pay for it. Uber only make more than that per hour
Sapher only US citizens pay for it.
ThatSaneGuy not to mention that due to the broke dick communist tax return system, the top 50% in income pay 97% of the taxes. Poor people essentially don't pay taxes, because their tax returns are so huge.
Caleb McCall ... that's only true for federal income tax
Thank you American taxpayers, because of you kids can play Pokémon Go worldwide.
And adults.
.:Camper:.
Pretty sure the strongest economy in the world isn't jealous about anything a shithole like the middle east has.
.:Camper:.
1: Don't like your own comments
2. Enjoy some of the highest rent costs and highest general supply costs in the world. Enjoy sand and nothing but corruption.
Your city is essentially a police state, the only reason crime rate is marginally lower than other cities of a similar size is because your people are too scared to even think about committing crime.
Dubai is the single berry in a castle of shit, and it's not even that good.
Anyway, I don't live in a city. I live on my own farm, with the freedom to do literally anything I want. A few weeks ago, I made an incendiary grenade and a rocket, and just fucking flung it.
.:Camper:.
Hit a nerve? 8 comments in a row
You're welcome, now shut the fuck up Sammy.
I've never scratched my head while watching a video until today
Seriously awesome information lol
2:19 Awesome easter egg if you look up what's actually there!
Connecticut? Nice pun!
@@stevey9350 No, it's the Smithsonian National Air and Space Museum.
Your content is really high quality and very interesting. Thank you so much for making it!
So in the end- they made it free of charge so we can play Pokemon Go!
Stefan Alexandrov no so they can study your habits and tendencies to better see to you. probably?
sd v they don't need GPS, GSM is already spot on
Stefan Alexandrov yes pokemon go can take video of strategic forbiden area, of new prototypes and is a perfect spy product. Why best polemon are always in restricted area ?
Pokemon - go to the polls
Guys you need to learn what sarcasm is...
I use offline maps all the time thanks to Gps. Great explanation of how it works. Never knew it was from military date.
I use the FPS, not the GPS. The FPS is the Flattard Positioning System. It will locate any flattard on earth to within 10 nanoplanes just by the odor coming out of their parents' basement.
The Ultimate Reductionist that comment made me laugh. And boy did I need that.
Thanks 🙏
Earth is flat get over it
@Steve Bingham it don't work like that ur baby brain can't comprehend how the flat earth works
@@Bullman8 Hi, go to your nearest university's geoscience department and ask them about gravimetry and maybe you can try out a gravimeter yourself. They are quite sturdy nowadays, not the thermos-in-a-foam-bottle thingys I used in mid-80s. Be curious! Do your own research! Gravity is out there, waiting to be measured! Maybe you can find an oil trap adjacent to a salt dome and drill and get rich!
The difference is flathearthers question everything but globers belive in evertbullshit because they need to convince themselfs and everybody else because they think that modern science revealed everything,and yet they dont know the smallest partical building blocks,every time they find smaller and smaller partical
GPS was originally available without scrambling, so if you captured your precise location before the scrambling began, then you could use those original coordinates to unscramble the scrambled system later for other coordinates.
I don't think that's possible because those scrambled coordinates should be totally random so you can't just unscramble it.
hats off to the men and women that came up with this and did all the hard work to get it to work
As a surveyor I use GPS (I think the GLONAS system) to measure sub centimeter measurements both vertically and horizontally. Its pretty amazing
From squad level radar to heat seekers that read differences in background radiation; Russian tech and the cognitive patterns it reflects are innovative and admirable. Doesn't suprise GLONAS is so precise.
Thank-you american taxpayers!
don't worry.... they print new money and pump in the market
GLR thats called inflation
@@neoney creative bookkeeping
I was about to ask it. You beat me before asking. Haha. You are welcome.
In this thread, people who have no understanding of economics.
A wonderful gift that can only have come from the heart.
Thank you real Engineering. You have never failed to quench my curiosity
I recall back in 1983 when that airliner was shot down. At first the Soviet Union stayed silent, hoping the world thought the airliner had just 'disappeared.'
Then a while later an audio radio aircheck, gotten from a CIA monitoring station, played at a UN gathering, the communication between the Soviet fighter pilot and his ground commander about that airliner being shot down.
It must have rattled the Soviet officials that the US had eavesdropping capabilities in a remote part of the world.
"100 meters, less accurate"
Me: turns _on_ google maps
*Blue mark drops on my house exactly where the bathroom and toilet is*
The 100m is an old accuracy estimate, as explained in the video. Today is really less than 10m, usually just 2-3m.
Source : I have experience in GPS testing
@@philipcooksey3422 in India it's less than 5 we have our own gps now called navic.
While I'm not an engineer I think it's awesome to have an opensource research platform.
I remember in the 90s, most gps handhelds had ways to circumvent the scrambled signals for increased resolution. That might also explain why they stopped scrambling...
As a grateful Canadian I have always said that America is the most generous country on earth 🇨🇦🇺🇸
Noone:
Real Engineering: *Cærs*
Cærs
GPS System? Global Positioning System System?
Yes. Just like an ATM machine.
Redundancy is useful sometimes.
meta
PIN number. Personal Information Number Number.
Yeah, I heard that the US government has the authority to retract GPS services at any time, at their own discretion. I did not know, however, that so many other countries have or are going to have their own GPS systems. Makes me wonder if the need came where the US considered pulling worldwide GPS services would really have an effect. Aside from any pilots like myself that may be in the air relying on GPS for safety and ease of navigation.
Which brings me to my other point. VORs are aviation navigational aids that link many major airports and locations and allow pilots to navigate over a radio, free of GPS.VORs are going out of service around the US as many pilots rely on GPS now as their sole navigating aid. This is unsafe and increases the risk of if something were to go wrong (say you lost connection, a satellite went dark, or the US pulled their GPS services) you would be stranded without traffic avoidance (unless you've already made arrangements with on-the-ground stations) or navigation aids. So please, if you ever hear someone talking about how VORs need to be put out of service, please steer them in the right direction.
Yes it would have an effect and let me tell you why. The other constellations have been developed to service only the local host's region and are not available outside. So if the US GPS went down, your phone wouldn't be able to track just because there's other constellations available. Only the US and to some extent Russia ( your device needs to have a separate GLONASS chip) provides positioning services for civilians globally. The European, Chinese, Indian and Japanese constellations only service their own region with only the European and Japanese constellation being open for full civilian use locally. The Chinese is mostly commercial and military sector use, and the Indian is Military (limited civilian later) only. Good thing the US and its taxpayers exist.
Skraith The equivalent of turning off every lighthouse on both coasts. I can see your point. The VOR serves as back up system nowadays.
GLONASS is widely available on smartphones even today. The European Galileo will be entirely for civilian use all around the world but I think they are running in some issues currently even though the system is officially operational.
Fortunately the new block IIIF sattelites that will be replacing half of the network won't have selective availability so 10 years from now, it could get hard for the US to degrade civilian accuracy without having jammers everywhere.
CharlieMason.. mate you're unfortunately wrong.. GLONASS (Russian GPS) is available as backup with global coverage. Almost all GPS units incl. the ones in smartphones nowadays have GLONASS support
Time dilation is such a cool. We can affect how time passes based on speed and gravity. The one thing binding is all together isn’t fixed but dependent on affects we can measure.
I hate to break it to you, but cell phones take the date/time from the local cell towers (stratum 2 clocks) in order to determine the local time. If you don't believe me, put your phone in airplane mode, then enable the GPS. You won't be able to get a lock because the phone's software won't use the internal battery clock, but instead relies on the clock from the cell tower.
Hikaru Katayamma but stand alone GPS's do know the time from the satellites.
Agreed, however his statement was specifically about cell phones, which is why I replied like that. It's one of the reasons that cell phone manufacturers piss me off so much. I know for a fact that you can run a GPS w/o cell signal, but they design it so that it won't.
Sounds like very bad software design on your phone's operating system, they simply deactivate GPS in AP mode. Timekeeping is inherent to GPS, so it is very hard to imagine how there even could be a GPS unit without its own internal clock, separate from the phone/OS clock. Cell tower time is not even accurate enough to use for positioning. As a software engineer I've been integrating mobile phone engines into other products (for tracking industrial goods etc.) - edit: maybe it was a design decision to save power. You may have noticed that the GPS receiver is one of the most energy consuming components on your phone. That's due to the very weak signals that need to be received. So perhaps the product designer was thinking "when people put the phone in AP mode, because they are in an airplane or hospital, they usually don't really want to use it. Let's turn the GPS off so the battery does not go flat by the time they switch it back on".
Source?
just tried it, my gps works in airplane mode
Bravo for this video! Sophisticated thing explained simply and quickly. Much much much thanks
Simscale looks amazingly interesting!
Have you tried them already?
Good segue from GPS to talking about your sponsor. Hats off.
Thank you for making this kind of videos! you are awesome!
Awesome video! Will you do videos about other satellite constellations? I know there isn't much information about this yet, but I really want to know why internet over satellite sucks and how SpaceX wants to change that, but needs 7500 satellites to do this.
I don't know all the reasons but I have read that SpaceX's constellation is going to be MUCH lower than the GPS orbit so they will need more to cover the area. And smaller (easier to produce satellites) will result in less powerful signals=more and an explanation for the lower orbit. I wonder if the lower orbit will make the quality of internet better??
Or in-formation space flight. That would be cool. Lots of research going into that for space junk retrieval and asteroid capturing.
Apace Sucks, because the satelites does not exist! They told to us that in space orbiting 37000 satelites but some places on the world even dont have GPS signal! How is that even posible! hahah! Google for it! Use your damn brain!
A bit late, but think about it. Satellites tend to be about 1-2x the size of a car not including the solar panels at full extension. Now that's big, but not nearly as big as the racks upon racks of state of the art servers that sit on top of the junctions in the fiber optic network that comprises the internet, not to mention the cooling the building itself provides form the air. Satellites have to deal with the heat in other ways. There is only so much computing power you can cram into a satellite along with the engine, batteries, transformer, and active cooling system, not to mention it has to be energy efficient, and also has computing power restricted by the components having to be radiation hardened to some degree to resist possible bit flipping corrupting information. This satellite is also at least 1000km above the surface of the earth, possibly 20,000km up in geostationary orbit, and has to receive an uplink from ground stations, provide its own uplink to a base station, provide downlinks to dozens maybe hundreds of said ground stations stations all on its own and in the middle of all of this, its trying to supply a steady, usable internet connection. Not exactly easy when you have the data center volume equivalent of a flaming shoebox to work with
"GPS systems"
GLOBAL POSITIONING SYSTEM SYSTEMS
Val D DC comics
PIN number
EMP pulse
Val D RAS Syndrome
"redundant acronym syndrome syndrome"
atm machine
and my personal favorite, Stargate SGU
Man it blows my mind that technology used in our everyday life has to account for a difference in passage of time for us in comparison to it. The way something like that is just so casually said and accepted makes me feel like Im in Star Trek.
People give the US a lot of shit but rarely give it the credit the country deserves.
what credit?
Because along with telling you exactly where you are, it also tells them exactly where you are.
And what you want to buy
Flat Earthers should not be allowed to use gps
Cable Yaj yes!
I concur.
jbbolts That's correct , GPS stands for Ground Propagated Signals.
GPS still works with a flat earth.
@hadi, you have no proof of that. The satellite simply flips over and stays in orbit.
The SR-71 had an "R2-D2" behind the RIO pilot that served as a GPS unit for the SR-71. There was a small circular window behind the RIO pilot that triangulated the stars while the plane was taxiing and gave the GPS of the plane. If it was cloudy, the plane had to be above the cloud bank to know its GPS.
Oh good to know
hey, Hank Green is a Patreon! How cool.
Galileo has actualy been operational since december 2016. Its just been made more accurate since and only recently fully completed.
Missed one important thing.
1 satelates makes a shell
2 satelates makes a curve
3 satelites makes a point (rather 2.. but one is far out in space)
So why do you need 4 satellites. The 4:th is to send reference time
more signals = increased probability of being accurate. The each satellite signal acts as a check on the box the other 3 draw, allowing the system to be that much more accurate. The more signals a receiver can process against each other at once, the better accuracy you'll get.
The point is that you really need 4 to have any position what so ever.
Despite the original post's bad spelling, he is correct. 3 satellites create 3 spheres which give you 2 points. But you have one more sphere in the equation: Earth. In the combination with that you know a specific point.
But the problem is that you need atomic clock time accuracy to make this computation and that is provided by the fourth satellite.
I hope this helped you understand. I studied GIS in university.
AFAIK, GPS doesn't even broadcast the position of the satellite, just the accurate time. That allows you to calculate the position with 4 signals, even if you don't have the accurate time yourself (the vid was wrong on that your phone needed the time)
Clifford Kintanar Wrong. The GPS always broadcast the ephemerical data, you can calculate and predict the satelite position based on this data and time of positioning.
the *commercial* aviation industry does not use it for navigation and collision avoidance, as far as I know (aero engineer here with not much experience in air traffic) navigation relies on radio beacons on the ground, and the Traffic Alert and Collision Avoidance System works via radio signals emitted and received by every plane. But, there are plans indeed to integrate GNSS (GPS) into aviation navigation in the near future!
By making it "free" but still control it's use, they can put certain limitations and restrictions on it.
Having the ability to turn the system off or cause random offset/shifts in the calculated gps coordinates if needed.
Their biggest fear is a foreign drone or attacker using a gps system to target major targets in the US.
it also limited the speed of competing space programs by reducing their need to launch large numbers of gps satellites into space, in turn delaying the advancement of missiles and other rocket technologies that could deliver nuclear warheads
Really informative, thank you.
Your adspace was as neat as your subject
any real picture on navstar ? all the satellite is fake CGI.. come on
TRUMP is president .. so I can die happy
If you haven't got medical cover in the US you might just die.
Move to England for NHS where they never die ??
not for being uninsured
Actually only the 'C/A code' is available, which is a very small part of the total GPS signal. It is access to this code that provides the 'Standard Positioning Service'. The really valuable access is to the 'P code' (or 'M code') which provides the 'Precise Positioning Service' which is used by the US military.
Aviation collision avoidance doesn't use GPS at all. It uses the plane's transponders.
Here a reason...WE PAID FOR IT!
Well. We paid for Nuclear weapons technology but you can’t get that shit so easy can ya ?
You missed a lot of funny and important bits. Like why they REALLY stopped scrambling the signal: there was not enough military units available at the time of Desert Storm, so they had to buy civilian units and thus stopped scrambling.
Or how in fact the receiver 'decodes' the signal (it does not, it just matches the pattern received to a set of patterns in memory).
Or why do you in fact need four satellites (your explanation is superfluous).
Also, the phones DO NOT get time from the satellites. They could, but they do not.
Also, GLONASS is hardly operational, there just aren't any non-GPS receivers in the world (apart from Russian military ones - presumably).
Finally, a lot of countries have their own GPS-augmentation systems (SBAS). EGNOS, WAAS, to name a few.
He already said that other countries have their own systems. It's only funny in your sick mind. It's amazing you even have 5 likes; man people are desperate to hear US hate
wow i did not know this... well i could just humbly say.. thank you america for the awesome free stuff.
Interestingly, Indian Positioning System🇮🇳 IRNSS: NavIC has resolution of 1 metre!
Still we use the US' GPS.
However, Qualcomm Snapdragon will introduce NavIC very soon.
NavIC is only for Indians
It's useless for other parts of the world
Its main essence is to locate Pakistan military moments in Kashmir
And yes it's more accurate than GPS
Thanks bro , I'm from India too and I didn't know this
If gps has for rest of world why you guys want indian gps...
@@cgpatil19 military purposes
Do you think US will give all the information bout enemy moments???
@@cgpatil19 US didn't allow India to use GPS during Kargill war. We can't depend on a foreign nation for our defence
And people still think the world is flat...
I know hate people that think the world's flat if so we be hearing bout it lol morons lol eh
Just fly high enough in a plane and you can see the curvature of the earth. Anyone who thinks otherwise never studied physics/science.
pasoundman or doesnt believe science because 'its just a theory'
+MegaMGstudios You confused the word "theory" with "hypothesis". A theory is a long, formal scientific explanation of a certain thing/things *and it has evidence to disprove anything that contradicts the theory.* It also has a law/laws (a law is a rule that can be used to predict things) and predictions (by using the law). On the other hand, a hypothesis is an explanation but is without evidence, a law/laws, nor predictions.
Trispectre i know, i quoted people who dont believe it, they always say 'its just a theory'
I am actually looking forward to see how the flat earthers try to explain this.
* "But muh holy book!"
* "illuminati Propaganda"
* "horizon is flat u cant explain so checkmate"
how about just let them be dumb on their corner and stop caring
Vitor Alves Seeing them lose an argument can be entertaining.
Have they ever explained anything?
Φίλιππος Κωστόπουλος Not really, no
I bought a Garmin GPS in the mid 90's for my workboat it was able to help me tru the fog in narragansett bay no problem. I remember the accuracy was +or- 50ft depending on how many satellites could be locked onto.
Mike fishead: Modern ones are more accurate....1 - 3 metres (approx 3 - 10 feet) is usual today. Mine is accurate to 1.5 metres / 5 Ft even indoors 🙂
781 flat earthers have watched this
The US can shut anyone's GPS system down also if they wanted to not just their own.
there.is glonass
ElfNet Gaming
They can shut the whole planet if they wanted to.
Mate, you just said Global Positioning System System.
and vice versa moron
Flat earthers haven't climbed enough mountains.
One question for you. North side of Dublin. Or South? These are the need to know questions.
+Magnificent Speed neither, Galway. My family are from Clondalkin though
Feckin right we are! ;-)
Doubtless developed for missile guidance, but I suspect it's not 'free' - I assume that GPS device manufacturers have to pay a licence fee to USA. Nonetheless, it's a fantastic development.
no license fees, but also no guarantees that it will be available forever or free. so you pay this way.
@@wm2008 I doubt it'll ever stop being free. What more can a military ask for than to be able to control other military's information?
Just $2M a day. Company like Google could do that on their own if one day US decided not to open for public.
Not really. They'd be broke overnight with the cost of building it.
Google has $80 billion cash. The cost to build and deploy 24 GPS satellites would be a few billion, tops. They could probably charge $10 per device for consumers (and a lot more for business entities) if there were no alternatives.
its more about having a spaceship to launch it and able to get 24 satellites into orbit. Where are they going to launch their rockets if the usa says they cant launch them inside our country?
Somewhere on the other 98% of the globe. Maybe the the US could sabotage or shoot down the launch, but Google knows the dirty secrets of everyone who might make that decision.
well i guess it would be possible... but google isn't really established enough anywhere else to have resources to start a fucking space agency and still have it somewhat cost effective.
Blew my mind
His explanation for how time is used by the receiver is simplified to the point of being wrong. The receiver doesn't need to know the time to get the position. Normally you would need three satellites to calculate your position in three dimensions. But if you don't know the time you can solve for it as well. That's why you need four satellites. Because you solve for four unknowns: Latitude, Longitude, Height and Time.
Interestingly, if you know your height (for example if you're a ship on the ocean) you can solve for Latitude, Longitude and Time with only three satellites. n practice though, you use as many satellites as you can to get a better result.
Why The US Military Made GPS Free-To-Use? Because a Korean passenger plane was shot down by the Soviets in the 1980s due to a navigation error. After that the US made GPS free to use for everyone.
But the receiver at least need to know a rough estimate of the time right? Otherwise, how would it be able to sync up its pseudocode with the satellites' code?
Jonas Eriksson
Interestingly, the satellites doesn't actually broadcast their position (since they move it would be wrong by the time the receiver gets it). Instead they send parameters (called ephemeris) that can be used to calculate the position at any point in time (or at least for the next couple of hours). Another thing they send out is the clock error, how far ahead or behind that particular satellites clock is to the real time. All those parameters are updated a couple of times a day from control stations on the ground.
He also said that "the radio signal travels at a known speed, the speed of light". Do people not use their brains any more? LOL
Jay Cadilak
Umm.. what? I have never said that. Stop making up bullshit to discredit me, the least you can do is provide a counter argument....fucking idiot
If something is free, you are the product.
The effects of gravity influence time dilation more, so wouldn’t the satellite’s clock need to tick slower than at the surface of earth in order for them to be in sync?
As an object experiments more gravity, time will pass slower, this effect also applies to fast moving objects, which is the case for gps satellites, so overall, time passes faster on earth than on those satellites, though, if they orbited at say, 100 times the speed, their clocks would definitely need to tick slower than on earth.
Google maps: let me introduce myself
Gaaay
They use US military satellites, dumbass
@@hahaaha7400 WoW you have problems m8
I still dont understand how gravity can affect time, like H O W
gravity is the strongest force of all u know that wright?
it bends light, it bends ur mum, it bends time
@@wik7or214; Is this What Makes You Bend????
Space and time in intertwined... It's weird man
Einstein’s theory of General Relativity is all about this, but you first need to understand his special theory or relativity first.
Very few people can follow them, but if you can, then you’ll get it.
This is an easy one to answer. If we assume that you use your phone to tell the time then, if you drop your phone, it will fall and hit the ground under the influence of gravity and smash into pieces - which will stop time. A clear demonstration of the way gravity affects time.
The first generation of public GPS had a built-in error so that they couldn’t be used as a weapon. But smart companies set up vans at known and accurate locations that radioed the error direction and amount to survey crews in the field. You see the error was the same for a certain amount of time. The survey crew received the error data and corrected their location. This caused the government to give up and simply send accurate locations on the GPS system. The military GPS also allowed cruise missiles to quit looking straight down and comparing the landscape to maps pre-loaded into the computer to go instead to high altitudes and then drop from the sky and accurately hit their targets.
don't say America never gave you anything everybody
because they needed to know where their soldiers in the cold war
@@carlosmedina1618 yeah that's how it started but what is important is where it ended
America didn't give anybody anything. The GPS system was built and is maintained by USA taxpayers. It's one of the few tecchie things that's worth a shit.
@@garychristenson6370 The United States taxpayers are the ones giving because they have voluntarily chosen to give access to everyone else. They are voluntarily giving access to everyone because there has never been mass opposition of free worldwide GPS.
@Sourav Kumar It is only costly for the Americans who pay taxes, it is without charge for foreign nations (with exceptions)
I am sorry to say, that there is an error in your video:
If you use 3 satellites for positioning it is possible to calculate the position (due to geometry, 2 Points could be calculated, one on the earths surface and one deep in space). One of these is not viable and can be ruled out... guess which one.
So why do you need the 4th satellite? The answer is simple (well actually its math so...).
If you use only 3 satellites you would need an exact clock (like the one build into the satellites). If 4 satellites are used you only need the time differences between the time broadcasted by the satellites (and a very basic clock provided by your phone, and a way to look up the positioning of the satellites based on their broadcasted time). So in no way is the satellite "setting" your gps phone time in any way.
Does this mean that the theory of relativity is not needed in order to obtain ones position?
it's just a theory and not a good one anyways, Tesla called it bullshit and so should you
top kek :Einstein's principle of relativity is a key element for GPS to work (perfectly explained in the video). Actually I am baffled how you come to this conclusion based on my comment.
m_endres Without the 4th satellite, you will also often have inaccurate altitude measurements, and the second location may not be in deep space, it sometimes ends up somewhere not on the surface of Earth, but near enough to Earth that it's technically possible if you're in a plane for example. The GPS just assumes you're not flying or on a mountain. The 4th satellite selects the final of the two locations though and ensures an accurate altitude as well as more accurate position in general making the service more usable.
Start from 04:00
Thx, i hate it when they talk and talk and never come to the point which made me visit the vid....
I came for GPS and now I am totally fascinated by Simscale... really nice tool
Assuming that there are 380 million people in the United states, we pay about 2 dollars per year. A good price, isn't it?
That's assuming everyone pays taxes. As always, us in the middle class picking up the slack for the lazy and those leeching off the government.
G is ×10^(-11) not ×10^11
I'm still thankful he didnt go like "omg this is so hard I know you wont understand how to do this math viewer" like all the rest of the youtubers. Like dude your plugging in numbers into an algrebra equation, almost all of us can do this. At max your doing some light derivatives which I get not everyone has done calculus but it still isnt the most overwhelming thing in the world.
#nerds
Also, the dimension of the gravitational constant is m^3/(kg⋅s^2) but not m^2/(kg⋅s^2)
Igor D www.universetoday.com/34838/gravitational-constant/
Igor D www.physicsclassroom.com/class/circles/Lesson-3/Newton-s-Law-of-Universal-Gravitation
According to Flat Earthers, this isn't possible. Must be a conspiracy!
TrollBuster true that gps is a ground base system no satilites lmfao
radio towers are on the ground globey
TrollBuster Most of their ideas are religion based.
Because their holy book says a man cannot leave the Earth due to the magical Firmament they must assume anything to do with space is fake, ie pics of the Earth from space ect..must be fake!
That leads them to decide that any kind of space orbiting sats cannot be real and the whole idea must be fake also.
Imagine if you 100% believe in god and science fact is proving otherwise......unless you change your way of thinking you MUST denounce everything else, otherwise your whole faith goes out the window.
Conspiracy theorists like to think they are in a little club and they know stuff no one else does.....it makes them feel special.
We know they are special...but not in the way they think.
I agree!
+Chad Owen _"true that gps is a ground base system no satilites lmfao"_ +Stewart Goodwin _"radio towers are on the ground globey"_ So you guys think it is somehow possible to multilaterate an accurate position fix, with altitude, using signals all coming from elevation angles just a degree or two above horizontal (as would be the case for any terrestrial radio towers more than a few meters away)? You could make billions licensing that technology - accurate positioning including altitude data without the massively extreme costs of launching and maintaining a large constellation of satellites would be a very lucrative business.
This kind of videos are like a commercial video with a very informative twist. Very nice
That was very nice of america 😘
Yet the world will continue to treat us like we're the fucking antichrist...