How GPS works without an atomic clock

[@famlrnamemssng]

This guy is super underrated. Short, easy to understand, and straight to the point. Love it

[@KnowArt]

thanks, those are kind words

[@anon_ninja]

Is it not a team of people?

[@famlrnamemssng]

@@anon_ninja I'm pretty sure it's just him doing all the work, but even if it's multiple people the content is still really good

[@anon_ninja]

@@famlrnamemssng it is good indeed. I hope they don’t run out of ideas. Very fascinating and information rich videos.

[@kilovolt2494]

Yes he is. I understood why the military needs atomic clocks.

[@ctcwired]

The fact that the animation and sfx are in-beat with the music is 11/10, instant subscribe.

[@KnowArt]

it's all custom made :)

[@skywarser1610]

​@@KnowArt that's niiiiiice !

[@GoldbergToastyBred]

@@KnowArt woah it probably takes a lot of time to just create this video, subscribed :D

[@KnowArt]

@@GoldbergToastyBred it does! Welcome 🤗

[@coolayd4254]

I was so confused for the first half but the visuals you gave really helped me understand it I really love your videos I honestly do They’re really fun to watch and helps me take a little break from work

[@KnowArt]

thanks a lot. that's great to hear

[@alltrysilver]

Great video! Never really thought about 3D "triangulation" before

[@KnowArt]

yeah I was also surprised to learn that it took 4 sats! And because it uses distance instead of angles it's called trilateration, or multilateration when it's about more than 3 points

[@crabbyboi9127]

they should call it pyramidation or something lol

[@Raven-rv9jr]

Technically its 4D since it accounts for the temporal dimension too

[@Flumphinator]

This is a game mechanic in EVE online.

[@AlanTheBeast100]

@StringerNews1 Tri-(or multi) lateration depending on how many sats you use in the fix. If 4, then it is tri, because one is thrown away to determine the clock error.

[@TMinusRecords]

Omg the music!!! Never seen someone make the music match the animation like that on KZbin before!

[@KnowArt]

great to hear that it doesn't go unnoticed

[@ChasePhilport]

the music is CRAZZY good wish you had more videos that weren't youtube shorts.@@KnowArt

[@Fkruus]

I've been having to explain this for a bit while teaching GPS. You've done it so much faster and more elegantly than I can on a white board. I will be using this! Thank you!

[@KnowArt]

thanks! Have at it

[@_invencible_]

I understand that this explains how the phone calculates its position relative to the 4 satelites, but how does it know the position of the satelites? Is it encoded in the signal or something?

[@rustteze]

​@@_invencible_bit late but yes, every satellite has an almanac (in the code transmitted) of all positions where it and all other satellites are and will be

[@_invencible_]

​@@rustteze cool, thanks

[@Yellowc0ld]

It’s insane how people were able to come up with something so complex wow!!

[@KnowArt]

absolutely mind boggling if you think about it

[@dhirajsaxena1971]

@@KnowArt and somehow it becomes surprisingly simple too at the same time!

[@vylbird8014]

The secret is having a giant pile of cash. GPS technology was developed by the US military, and initially for purely military applications. Only cost twelve billion dollars. Funding is no issue when it comes to bombing the commies. Only after it was deployed for military purposes were civilian uses for the GPS system found. It wasn't opened up to civilian use entirely until 2000 - until then the high-precision timestamps were encrypted, and civilians restricted to use only a deliberately inaccurate, degraded service that was only accurate to within a few hundred meters - good enough to find lost hikers, not good enough to aim a missile. The military applications are also why there are four satellite navigation systems now. The US launched the first, but none of the superpowers want to be dependent upon a navigation technology that the others could potentially lock them out of in a war. So Russia, China and the EU collectively each run their own. This is rather wasteful of resources, but at least good for people who use it - most receivers are multi-system compatible, and with the sheer number of satellites to choose from it's really easy to get a location.

[@TwskiTV]

Insane how, within the same race, some individuals can create such amazing technology, while others believe that the Moon landing was faked and that the Earth is flat

[@vylbird8014]

@@flabiger There's an altitude limit as well. Wouldn't stop any military building their own units, but it stops some guerillas from strapping an off-the-shelf GPS chip to a second-hand aircraft to make a DIY cruise missile

[@Hari-du6pt]

The moment the graphs exploded into 3D and the awesomeness of this technology was visible I felt actual excitement - the sound, the visual, the narration - really cool short videos!

[@KrazyCouch2]

You are so unfathomably good at explaining. If I had to explain this concept as simply and easily accessible as you have I would have no clue where to start!

[@KnowArt]

Thanks a lot

[@rtxagent6303]

It is honestly so insane how we as a species have managed to achieve this in only a couple centuries after the light bulb was invented. Such a complex thing that almost everyone takes for granted.

[@mrchangcooler]

It's basically subtracting each dimension in our 4d spacetime every satellite until you get a single point in space, just using time and the known distances at the satellites to give a lookup table. Each timestamp from each satellite subtracts one from 4d spacetime until you get a 0th dimension, one point in both time and space.

[@areadenial2343]

That's really interesting! You first narrow it down to a 3D surface, then a 2D arc, then two points on a 1D line, and finally a single 0D point.

[@volovodov]

I think I'm in love with the sound design of this video.

[@alexandrubossro]

The fact that this video is that quick and straight to the point without 20 min of history and stuff, is really nice. Subscriber earned

[@vylbird8014]

Three satellites suffices, barely. There will be two valid solutions to the equation, yes - but one of those solutions is going to be well outside of the atmosphere, or appear to be moving at somewhere in excess of the speed of sound. So it's easy for the GPS receiver to tell which is the correct location. Having a fourth satellite does allow for improved timing correction though, which greatly reduces error and allows for a much more accurate fix. You can use more satellites for even more precision, but you soon hit the limiting factor - the atmosphere isn't quite perfectly transparent to radio, it distorts the timing of the signals very slightly depending on temperature, pressure and humidity. So if you need really, really precise GPS tracking you have to use a nearby reference receiver that can constantly measure that distortion from a fixed location and send the measurements to your GPS receiver. Expensive stuff, but you might find one in use on a large construction site being used to make sure all the utility trenches and buildings go in the right place.

[@bradley-jamesnorris4499]

That’s amazing, bite sized and informative. I learnt something new today

[@KnowArt]

great to hear, thanks

[@vagnersilva5465]

Okay... but HUGE PROPS to the animator and sound designer. Seriously... as an animator myself, i salute you guys

[@KnowArt]

thanks!

[@marlonb1852]

Dude, the sound design is insanely satisfying, let alone your clean explaination.

[@Desam1000]

This very exact visual explanation which corresponds to the actual implementation I did on a mobile device (not a phone though) made me subscribe to this channel.

[@oriongabriel6966]

Fun fact: this is the reason why the malaysia 370 search area was an arc. Because a satellite called the onboard satellite phone. They got a distance from the satellite to the plane and therefore got an arc across the ocean of possible areas the plane could have been. 🙏

[@KnowArt]

really!? that's a cool fact

[@zkxrpyun]

Very well presented, vocally and visually. Detailed yet concise, all within 2 minutes.

[@hrishikeshharitas2456]

I can totally imagine this being a 15+ minute video from any other channel

[@THERedstoneBR]

this could be a 30 minute video long, but you have preserved my time and go strait forward, i liked alot

[@CJBTYT]

Wow! Nothing has ever gone faster over my head than this video.

[@AlexanderPrussak]

I love the audio + 3d visual demonstrations. This fucking rocks

[@LouisCognault]

Very nicely explained! Not too basic, not overcomplicated, just perfect! Thank you!

[@ThisIsTenou]

This was incredibly helpful, and you did a stellar work at animations and especially the music. This video was an amazing experience.

[@pierovazquez7591]

i think this is the best add for brilliant that i have seen

[@jamessovea4993]

This could've easily be extended to a 30min video. This is so much better

[@sukalpashrestha]

Great video dude. These are awesome for how simple and clear the explaination is

[@The_Tauri]

I dont understand why this channel isnt already in the millions of subs range and the videos dont get 400K views regularly - the quality is way up there. Which means it'll get there sooner or later. I also dont get why the almighty YT Algorithm didnt recommend this channel to me earlier, its right up my alley! But glad I found this channel at last!

[@starmanxvi]

Seriously the greatest channel ever

[@boggybolt6782]

Love it. Had this exact question for a long time. Thanks for the answer

[@KnowArt]

My pleasure

[@bloomface9146]

I am amazed at how hyperbola can be used in such an elegant way to pinpoint location.

[@MichaelGrundler]

I've known for years (or decades?) how GPS works in principle using the explanation with the spheres, but this video was the missing link to finally understand how it can work without having a synchronized clock on the receiver side.

[@Life4YourGames]

Now this is one gem on the internet! You're doing amazing educational content, thanks and keep going! ^.^

[@gabedarrett1301]

I have wondered about this for years! Thank you!

[@mindaugasv85]

Have you ever wondered what is in these signals (what data)? 😁

[@godzilla928]

You're my new favourite 'how it works' channel

[@atlas7309]

I really liked the choice of music.

[@mohammadal-kamsha4020]

The more and more i realize the technology is actually simple and ryey DID actually tought me everything in high-school but i wasn't paying attention.

[@worthlessman9214]

its good to see a short video without subtitle punching on face at this time

[@Dersephh]

Sometimes shorts aren't really that bad after all. I found out about this channel from that. You really did a veeery great job on these type of videos

[@KnowArt]

thanks!

[@e-berry]

You simply are amazing, please continue

[@VicJang]

This is incredible. I love this channel.

[@remboldt03]

Wow, I didn't know you made normal videos. I subscribed and liked almost every short

[@LuizDahoraavida]

Awesome stuff, gives me a bit of a bill wurtz-ish but sane vibe, which I think is really cool, visualization with graphics really go a long way on topics like this!

[@ZED-PV]

This video is ridiculously good... Subbed

[@creator8101]

Wow this guy needs to be known by everyone in youtube

[@deadsimple]

I sense a kindred spirit. Good job!

[@adix64]

Beautiful channel you have sir!

[@KnowArt]

thanks

[@FranzBiscuit]

There is also a relativistic correction involved which deserves mention. But otherwise interesting video. Subscribed!

[@koharaisevo3666]

Have to watch the video 3 times but now I get it.

[@ulogy]

The phone knows where it is by knowing where it isn't.

[@kkaze]

Really talented music!

[@murirokcs5518]

bro your graphics are insane, I say you're underrated

[@anirudhnair558]

I love your videos dude!

[@KnowArt]

thanks!

[@raulgauthier7893]

DAMNNN these edits are sick

[@nxone9903]

Thats some insane maths

[@177unneh]

very cool animation and explanation!

[@shubhamarutwar9396]

if you think about it, its insane that we are able to calculate time so precisely that we are calculating distance on basis of that. that too with less than 5m accuracy from space.

[@FAB1150]

Oooo this is a question I've had for ages! Thanks!

[@iamthinking2252_]

Holy shit is just like that Udvar Hadzy museum bit on LORAN

[@AnoniChocolateMoose]

Ok so thats whats needed by luffy to find the laugh tale island

[@jackygrush]

These videos are amazing

[@obvjxcob]

first one is TOO relatable.

[@jcf_1760]

DANG I never understood something so complex so fast!

[@SolaceCafe]

I like your long form content a lot, more in depth :)

[@KnowArt]

thanks. More is coming :) but they also take a long time to make, so it might take a while

[@mrp1zz492]

Its something we dont think about in our day to day, but it takes so much to do it😮

[@Redwan777]

2 sattelites to create a hyperboloid 1 more sattelite to get a line 1 more sattelite to to get 2 points 1 last sattelite to know the correct point That's 5 sattelites not 4

[@raniem4368]

2 Sattelites to create a hyperboloid. Correct. 1 More satelite to get a line. Correct. 1 more satelite to get 2 points. Incorrect. You have 3 satelites, so you can calculate a third hyperboloid.

[@satibel]

note that in most cases you don't actually need 4 satellites, because the 2nd point is rarely on the surface of earth. (the 4th intersection is actually earth.) though in practice, you usually want around a dozen satellite for good precision. there's also RTK and DGPS which both use a base station that has a fixed location and then from that you can know the position (relative in the case of rtk, absolute in the case of DGPS) of a moving gps (e.g. a robot lawnmower) with an accuracy of 1mm-5cm (depends on the chip and if using mixed ) and nowadays, at least on phones there is Assisted GPS, where instead of getting the satellite's position from the satellite itself, which can take 15 minutes, the position is given by the network or radio. but full positioning is provided not only by GPS, but also other types of GNSS (like GLONASS Galileo and BeiDou), the distance to different radio antennas, wifi networks, and occasionally some other types of wireless signals. the idea stays the same though, take the distance from known points and now you have your position.

[@onewaygaming8380]

In the future, it would be a good idea to linger a bit longer on some visuals such as the time one compares to distance, it was a bit fast to catch. Great video though :)

[@kolyashinkarev7366]

Also the fact that gravity affects how time flows is taken into account when measuring the distance

[@owlofthenights3680]

Earned a subscriber!

[@urgo224]

Don't forget that the GPS satellites also have to account for time dilation between orbit and the surface!

[@ssa7843]

Lovely! First time i understand the time sync problem🎉😊. At 00:20 you say you need 4 satellites without clock problem, why not just 3 spheres? Two spheres make the line and three spheres a point i would assume

[@thomaspitter3229]

I have always wondered how GPS overcomes the inaccuracy of its own clock (though apparently not enough to warrant a google search xD) and now, just like that, I know! Love your style of short explanations (though not "short" short, which is a plus!)

[@JonBrase]

The 4th satellite is there more to eliminate the need for a local clock than to choose between the last two points.

[@harshanon]

Suddenly I'm discovering new dope and underrated channels... First the depressing turtle Then the Bluetooth guy And now the GPS guy XD

[@KnowArt]

tell me their names! now i'm curious

[@TheCrimsonKnight.]

I wish I could subscribe to you twice! I plan to sub to your Patreon once I have consistent expendable income :) Keep up the amazing work! Your community loves you, don't forget that. Take breaks if you need them :)

[@bakdiabderrahmane8009]

wow, subscribed immediately.

[@crschoen123]

Your phone's clock doesn't need to be in sync, but the satellite's clocks do

[@alluseri]

This is the perfect food for my low attention span 1 AM brain.

[@seamali4383]

Scientists are underappreciated in society.

[@MasterHigure]

And this is why, if we hadn't corrected for relativity, people are wrong to say GPS would drift kilometres per day. Because GPS doesn't in any way rely on the absolute time of the receiver. And all the satellites would have the same error, which means the difference between the signals would be entirely correct. The actual error from not accounting for relativity is that the satellites wouldn't send out signals when they are supposed to, so they wouldn't be in the position they are supposed to when they send it. And this error would drift by about 15cm per day. Not kilometers.

[@kakurerud7516]

wow my tictoc slab is so smart!

[@sgtrogers]

Wow. I love this video.

[@plechiunofficial6267]

MAGIC

[@Terrain239]

Unfortunately, computed hyperbola from the first two hyperboloids will end up inside the third mentioned hyperboloid (from 1st and 3rd sats), so to get two points you need to add the fourth sat. (And to choose between those two points a fifth sat required) This can be showed geometrically, but also algebraically: you have 4 unknown variables (x, y, z, t), so you need at least 4 equations to get non-infinite number of solutions

[@iZai53]

Says no more, pressed sub!

[@245trichlorophenate]

This is amazing! How do you make your visualisations?

[@KnowArt]

I use Blender and sometimes my brain tries to help too!

[@klamky]

so THIS is what all that math was for

[@austinjon31]

How did you animate this video so well? HOW?!

[@KnowArt]

I use Blender and sometimes my brain

[@FrendzeL222]

1:23 - 5th* not 4th ;)

[@willpulford8893]

F me man, this would be incredible to watch while stoned. Seriously mind blowing instantly subscribed: Edit nah I overestimated how good being stoned would be. Still a great video though 👍

[@KnowArt]

haha enjoy my content however you wish. Welcome

[@khushmishra8709]

Tell this man how to make fusion reactors and every kid will know how to make one 😂

[@user-jk2zm7uq5s]

Since you very often kind of know where you are ("somewhere in Manhattan" + "NOT New Jersey") the GPS could offer you two possible points if it only receives the signal of three (instead of four) satellites and you'd still know where you are ;)

[@РыгорБородулин-ц1е]

Absolute banger

[@dj_laundry_list]

This is what people and bots mean when they say "triangulate"

[@Tombaysbot]

I actually would like to know the other thing: As our world isn't ideal, you can't determine the exact location, you always have to approximate. How do our phones approximate their location out of these four satellites? Mathematically, i mean

[@rallyworld3417]

1:03 got lost here

[@Fester_]

I wish I wasn't so stoned.