FCC chair says we’re too dependent on GPS and wants to explore ‘alternatives’.
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Also, you know how to make GPS more reliable, secure, and redundant? You launch more GPS satellites.
But where will we find room for more Starlink satellites if we do that? Elon said he needs another contract, and when the boss says jump...!
/s
One can use both and anything else frankly, isn't it enough to triangulate the signal between 3 satellites (or 2 with an interval and knowing their trajectories relative to each other) and match the spot on the geoid's (stored model, position precalculated by time) surface?
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It's also just a generally bad idea to be too dependent on a single system. If GPS reception fails for one reason or another, it would be good idea to have a backup.
It’s also just a generally bad idea to be too dependent on a single system.
You're saying this in the world where SMS is considered good for 2FA, and PSTN identifier is considered as good as your citizen's ID, and people's lives depend on systems incorporating NodeJS and Kubernetes. Yeah, by the way, Docker everywhere, and all the POSIX standardization and source-compatibility to allow different systems adhering to standards ... have lost to Linux just becoming another main target.
But yes! It's a bad idea. Also it's typical now for these systems to start lying in warzones where their owners don't want one of the sides to have satellite navigation. They then give shift maps or whatever to the side they want to win.
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How do we call these assholes and tell them to get their heads out of Muskovitch's ass?
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Having functional GPS in a tunnel would be very nice...as someone who drives through Boston and fucking hates tunnels.
But that's not what I meant by fragile. I meant it can be disrupted/jammed fairly trivially.
There's no reason why some sort of augmentation system couldn't improve the navigation situation with the big dig. Stick some low power beacons that provide GPS-like signal in the tunnel based on their predetermined location and we'll have GPS accounting for special relativity, general relativity and continental drift.
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Phones already do that with cell towers. It's called A-GPS (augmented GPS). Cell towers are used in addition to GPS signals.
Is that the difference between when something like Google Maps has your general location and when it has your specific location?
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Also, you know how to make GPS more reliable, secure, and redundant? You launch more GPS satellites.
But where will we find room for more Starlink satellites if we do that? Elon said he needs another contract, and when the boss says jump...!
/s
Starlink is LEO, GPS is not.
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Isn't GPS a US project?
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You are so close to VOR!
Oh, so that's what that saucer is for.
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Starlink is LEO, GPS is not.
And I'm sure that's a distinction politicians really care about. /s
Your answer is rational. US politicians are not, since they have an agenda to hand off their money and power to Trump and Elon.
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No, you need 4 minimum.
Two satellites intersection places you on a circle. (all points possible)
Three satellites intersection places you on two possible points.
The last satellite give you the exact location.
However, often the 4th is omitted if one of the 2 points is not in a sane location. (eg well below the crust). And it's trilateration not triangulation.
three sats determine your accurate position. the fourth is for clock correction only.
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The earth isn't flat.
So which coordinate accounts for elevation? Latitude or Longitude?
Lat/Long is only valid if elevation is valid. You can't reference a lat/long that is miles into space... or beneath the crust of the earth.
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three sats determine your accurate position. the fourth is for clock correction only.
No.
Satellites project a sphere, you need 4 in order to get to a singular point. I've outlined each step. Fourth isn't for clock correction only. And even outlined why sometimes 3 is okay, but that requires additional logic that many gps devices sometimes can't compute, and even outlined that the vast majority of devices will use way more than 4.
https://gisgeography.com/trilateration-triangulation-gps/
https://www.gps.gov/multimedia/tutorials/trilateration/ -
Isn't GPS a US project?
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You know what's a great backup? The ability to read a map or use a compass. This is set up to get Starlink or another billionaire to own GPS.
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Lat/Long is only valid if elevation is valid. You can't reference a lat/long that is miles into space... or beneath the crust of the earth.
It's like you're making my point for me.
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Reject modernity, return to sextant.
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It's like you're making my point for me.
A watch... or other simple gps device doesn't know what the elevation is.
Only one of the 2 selected points in a 3 satellite setup will be valid. And your device would have no idea which one is valid without elevation knowledge or a 4th satellite. Some devices can figure it out with just 3 satellites. Many/most won't. But ultimately it's the same thing. You need 4 pieces of input. Either 3 satellites AND elevation. Or 4 satellites.
So no. I've not made a point "for" you. You're just ignorant or specifically being obtuse on something you clearly don't understand.
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A watch... or other simple gps device doesn't know what the elevation is.
Only one of the 2 selected points in a 3 satellite setup will be valid. And your device would have no idea which one is valid without elevation knowledge or a 4th satellite. Some devices can figure it out with just 3 satellites. Many/most won't. But ultimately it's the same thing. You need 4 pieces of input. Either 3 satellites AND elevation. Or 4 satellites.
So no. I've not made a point "for" you. You're just ignorant or specifically being obtuse on something you clearly don't understand.
A watch... or other simple gps device doesn't know what the elevation is.
My point, exactly
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A watch... or other simple gps device doesn't know what the elevation is.
My point, exactly
Which is why they'd need 4 satellites. Read the whole post. Read the given sources. Stop being stupid.
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Nah the idea is sound. As someone else said, GPS is incredibly fragile. Also very terrestrial...it doesn't work once you leave the atmosphere.
This will probably be another SpaceX grift, but there are alternative technologies that are more resilient to attack. From military/defense perspective (the original reason for GPS), that's pretty important.
it doesn't work once you leave the atmosphere.
Fun fact: just this past week an experiment on a lunar lander confirmed that GPS signals can be detected from the surface of the moon. I don't know if those signals can give any kind of location precision, but it is an interesting finding.
