GPS has made a major impact on our world. How is it a free service that anyone with a phone can access? How is it profitable for companies to offer services like navigation without subscription fees or ads?
In: Technology
So GPS is actually a network of satellites all over the world that each emit a signal. By measuring how strong the signal is you can tell how far you are from a satellite, by using 3 of those signals you can pinpoint where you are on earth. Since it’s just listening to a signal being broadcast you cannot make it not free , at least not without tearing it down and building something different.
Now knowing your position on earth is very useful in some cases but not super useful to your average person on your average day. Companies do use resources of different types to map the area and even to monitor traffic conditions. Apple and Google give this as a benefit of using their platform , but google among others sell this data in bulk to companies who have high use cases.
Also it should be noted that what most people have in their phones also uses nearby wifi signals to help lock down where they are quicker.
Shitty ELI5 – most services advertised as “free” have long Terms & Conditions where somewhere in there you agree to the following:
* Give data
* Give phone number
* Allow access to your location
Outside companies pay good money for this stuff. Including the gov’t.
The military created, pays for it and maintains it.
Like much of the public infrastructure technology initially developed for military applications, it has massive value to the public and economy, making access free.
The public good and economic activity enabled by GPS is overwhelmingly worth the cost of maintaining the network for free use.
Since the signals are one-way from the satellite down, adding more users incurs no extra cost, so the military can give commercial use access for free.
The US military reserves the right to disable GPS and limit the accuracy of consumer devices locally. Because of this, other Global Navigation Satellite systems are available from the EU, Russia, and China. Galileo, GLONASS, and BeiDou, respectively.
Because the Soviets shot down a civilian airliner thinking it was a US spy plane.
In 1983, the Korean Airlines flight KAL007 was flying from New York to Seoul. They drifted from their planned course, and accidentally ended up in restricted Soviet air space. The Soviets intercepted it and shot it down. All passengers and crew were killed, including a US Representative.
GPS was still in development at this time, but it became clear that it would be a public good to help prevent incidents like this. President Reagan ordered that it be declassified and made publicly available as soon as it was ready.
Even though it is a military asset, the civilian use of it is simply the reception of a signal. Or rather, several signals, since that’s how GPS actually works. Everything else that goes along with your navigation apps is cartography.
GPS was started by the US military to better track troops and equipment. I cant remember who but some senator said “if the public paid for the program, they should benefit.” So the military changed the encryption and unencrypted a large chunk of the signal. And made it public access. And the entire world benefits.
2 cool facts. Most GPS units only use 3-4 signals to triangulate your position, but there are dozens of-it-yourself GPS kits that will read all available signals, up to 7-8, and give you sub 1 foot resolution. 2nd, during the early gulf war thete were not enough military GPS units, so the government turned off all encryption and the military used off the shelf units. The side effect was that the world got the best GPS resolution ever.
Who’s going to pay for the Grossi Perna show?
I always imagined anybody using a GPS chip paid a license fee or something. The same way that it used to cost audio engineers money to use the .MP3 format.
And after time both technologies paid for themselves and have become almost open source.
my question is how you gonna charge a subscription when GPS sats are just clocks pingin out RF times 24/7?
this is a really cool old video of what equipment was originally used to get GPS coordinates. and also to see how long it used to take.
You know how in the past people navigated using stars? You would know that a pole star can be used to navigate north, and being in a constant location it makes it a great way to navigate.
Take a few of stars like this – and you can determine your longtitude and latitude fairly well.
Now GPS works exactly like that. Just instead of stars – we have satellites. And instead of emitting light – they emit electromagnetic waves that GPS receivers can see.
So when the GPS receiver (mobile phone, tablet, Garmin, etc) receives signal from a bunch of satellites – it does some quick math and computes it’s location.
This mechanism, however, is also the reason it’s very difficult to provide GPS as a paid service. You can’t make GPS satellites only visible to paid subscribers – they are visible to everyone. The only way would be to encrypt the signals they send – but then nobody can access them. And if you sell decryption keys – they will be leaked on the first day.
Barely related, but my old Honda was one of the earlier ones with GPS navigation built in. It had a troubleshooting mode where you could “see” the navigation satellites it was using. I thought that was kind of cool, but not something you see in modern cars because there’s really no need for it.
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