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
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.
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