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Remember, GPS is a military tool first. Civilians get to use it at the militaries discretion. They could turn the selective availability (which was turned off i

Remember, GPS is a military tool first. Civilians get to use it at the militaries discretion. They could turn the selective availability (which was turned off in 2000) back on and remove a lot of civilian accuracy. Maybe civilian pilots are the ones that need to training aids more than the military. It seems to me that they should be able to navigate without gps in a safe manner. Edit: fixed term for selective availability.

Crosseye_Jack 5y ago
Didn't they actually remove selective availability from the new sat's that were launched. https://web.archive.org/web/20080113123316/http://pnt.gov/public/sa/ https://web.archive.org/web/20080113123316/http://pnt.gov/pu... > In September 2007, the U.S. Government announced its decision to procure the future generation of GPS satellites, known as GPS III, without the SA feature. Doing this will make the policy decision of 2000 permanent and eliminate a source of uncertainty in GPS performance that has been of concern to civil GPS users worldwide for some time.
- pmorici 5y ago
  I think it is a moot point because there are 5 position constellations now days (US, EU, China, Russia, Japan) and many popular consumer chipsets can use multiple if not all of them.
  - KennyBlanken 5y ago
    It's not moot for aviation, where GPS units can be decades old, in part due to how expensive avionics are due to an absolutely mind-boggling amount of FAA regulations. The FAA is a giant lumbering dinosaur that spends a lot of time making sure private pilots generate huge reams of paperwork and restricting the kinds of equipment that can go into various categories of planes, when the overwhelming majority of GA crashes are 1)controlled flight into terrain and 2)running out of fuel. We'd have a lot less controlled flight into terrain if the FAA would unclench its avionics regulations asshole. Thankfully anyone can run an iPad with Foreflight, or any number of iOS and Android apps, that provide rudimentary terrain awareness and backup navigation.
- takk309 5y ago
  I was unaware of that. Thank you for the bit of knowledge!
toast0 5y ago
> They could turn the selective availability (which was turned off in 2000) back on I'm not sure if they can, if I've got the right info, block IIF and block III satellites don't have the hardware for selective availability; and those make up 16 out of 30 operational satellites (and one out of 4 reserve). But I'm sure if they can't enable SA, they could likely just disable the civilian frequencies or something if needed. OTOH, there's GLONASS, Galileo, and BeiDou; the US can administratively deny GPS and probably Galileo, but not the other two, which makes SA less useful.
dkarl 5y ago
> Remember, GPS is a military tool first. Civilians get to use it at the militaries discretion. That's a bit like saying Java could have dropped sun.misc.Unsafe at any time because it was a private API. Once the civilian economy started relying on GPS, the military had to consider the cost of turning it off. Not to mention that the U.S. military has traditionally been deployed to promote and safeguard American commercial interests, and if it started disregarding them, that would amount to a shocking political revolution.
- posix_me_less 5y ago
  > the U.S. military has traditionally been deployed to promote and safeguard American commercial interests Any examples except maybe Kuwait? Korea and Vietnam were for geopolitical reasons, "to stop communists taking too much power", Iraq was few people taking advantage of 9/11 to line their pockets with government procured money. Afghanistan was the latter again. Which American deployment directly safeguarded American commercial interests?

Crosseye_Jack 5y ago

Didn't they actually remove selective availability from the new sat's that were launched. https://web.archive.org/web/20080113123316/http://pnt.gov/public/sa/ https://web.archive.org/web/20080113123316/http://pnt.gov/pu... > In September 2007, the U.S. Government announced its decision to procure the future generation of GPS satellites, known as GPS III, without the SA feature. Doing this will make the policy decision of 2000 permanent and eliminate a source of uncertainty in GPS performance that has been of concern to civil GPS users worldwide for some time.

pmorici 5y ago
I think it is a moot point because there are 5 position constellations now days (US, EU, China, Russia, Japan) and many popular consumer chipsets can use multiple if not all of them.
- KennyBlanken 5y ago
  It's not moot for aviation, where GPS units can be decades old, in part due to how expensive avionics are due to an absolutely mind-boggling amount of FAA regulations. The FAA is a giant lumbering dinosaur that spends a lot of time making sure private pilots generate huge reams of paperwork and restricting the kinds of equipment that can go into various categories of planes, when the overwhelming majority of GA crashes are 1)controlled flight into terrain and 2)running out of fuel. We'd have a lot less controlled flight into terrain if the FAA would unclench its avionics regulations asshole. Thankfully anyone can run an iPad with Foreflight, or any number of iOS and Android apps, that provide rudimentary terrain awareness and backup navigation.
takk309 5y ago
I was unaware of that. Thank you for the bit of knowledge!

toast0 5y ago

> They could turn the selective availability (which was turned off in 2000) back on I'm not sure if they can, if I've got the right info, block IIF and block III satellites don't have the hardware for selective availability; and those make up 16 out of 30 operational satellites (and one out of 4 reserve). But I'm sure if they can't enable SA, they could likely just disable the civilian frequencies or something if needed. OTOH, there's GLONASS, Galileo, and BeiDou; the US can administratively deny GPS and probably Galileo, but not the other two, which makes SA less useful.

dkarl 5y ago

> Remember, GPS is a military tool first. Civilians get to use it at the militaries discretion. That's a bit like saying Java could have dropped sun.misc.Unsafe at any time because it was a private API. Once the civilian economy started relying on GPS, the military had to consider the cost of turning it off. Not to mention that the U.S. military has traditionally been deployed to promote and safeguard American commercial interests, and if it started disregarding them, that would amount to a shocking political revolution.

posix_me_less 5y ago
> the U.S. military has traditionally been deployed to promote and safeguard American commercial interests Any examples except maybe Kuwait? Korea and Vietnam were for geopolitical reasons, "to stop communists taking too much power", Iraq was few people taking advantage of 9/11 to line their pockets with government procured money. Afghanistan was the latter again. Which American deployment directly safeguarded American commercial interests?