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
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.
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Which is why they'd need 4 satellites. Read the whole post. Read the given sources. Stop being stupid.
I did read the whole post. Stop being an asshole.
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GPS depends on a friendly spectrum. I suspect the FCC is preparing for a war where GPS will be jammed, faked, or destroyed.
How's the FCC going to prepare for anything when it's being gutted?
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I did read the whole post. Stop being an asshole.
Clearly you didn't... You keep asserting false statements that have already been disproven with sources.
But ultimately it’s the same thing. You need 4 pieces of input. Either 3 satellites AND elevation. Or 4 satellites.
If a watch doesn't "know" elevation (barometer or other sensor providing such information) as the fourth data point... Then it NEEDS 4 satellites to make the data points whole. Making your statements yet again wrong. I've covered the cases... but you keep pushing false statements like "gps is triangulation" (completely incorrect) or "GPS uses 3 satellites" which is also only correct in one very specific case... Where it's largely 4 or more, with reality being more like as many satellites as the device can read the pulses for. Often being a dozen or even more...
I am making accurate and complete statements. You are the one peddling misinformation.
Hell to prove the point... my time server grabs GPS as it's primary source. It grabs up to 12 satellites to sync time. It shows me my sync status for lat/long as well... At 3 satellites it CANNOT get a lock for location OR time. At 4 it gets a weak lock.
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Clearly you didn't... You keep asserting false statements that have already been disproven with sources.
But ultimately it’s the same thing. You need 4 pieces of input. Either 3 satellites AND elevation. Or 4 satellites.
If a watch doesn't "know" elevation (barometer or other sensor providing such information) as the fourth data point... Then it NEEDS 4 satellites to make the data points whole. Making your statements yet again wrong. I've covered the cases... but you keep pushing false statements like "gps is triangulation" (completely incorrect) or "GPS uses 3 satellites" which is also only correct in one very specific case... Where it's largely 4 or more, with reality being more like as many satellites as the device can read the pulses for. Often being a dozen or even more...
I am making accurate and complete statements. You are the one peddling misinformation.
Hell to prove the point... my time server grabs GPS as it's primary source. It grabs up to 12 satellites to sync time. It shows me my sync status for lat/long as well... At 3 satellites it CANNOT get a lock for location OR time. At 4 it gets a weak lock.
You keep asserting false statements that have already been disproven with sources.
I don't. You just aren't paying attention to what I'm saying. You keep arguing up a strawman.
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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.
Ding ding ding. This is just a talking point so they’ll be able to pivot into “we should give Musk a trillion dollar contract to run GPS on his Starlink satellites”
