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[deleted] t1_j5pg67z wrote

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rustle_branch t1_j5pvshx wrote

Selective Availability was the intentional degradation of the civilian C/A code. This was turned off in 2000 by executive order - civilian receivers have been capable of sub-meter precision since

There is a second encrypted "p code" reserved for the military on a different frequency - this allows for even greater precision (not sure how much greater) because you can use the two signals at different frequencies to "cancel out" ionospheric errors. But there are other ways to handle ionospheric errors, depending on the application

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[deleted] t1_j5pw66i wrote

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rustle_branch t1_j5pwym0 wrote

Youre right, but i already felt i was too in the weeds for a reddit comment lol

Point is, until SA was turned off even with DC high precision wasnt possible (to my knowledge, at least - i know my gps professor had spent some time trying to find workarounds to SA but didnt get much success before it became moot)

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[deleted] t1_j5pxb3h wrote

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rustle_branch t1_j5pxkgl wrote

Any idea how accurate it was at the time? Its been several years since i did anything with gps so im pretty rusty, appreciate the clarifications

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GATORSEMENSLURPER t1_j5pveyu wrote

NAVSTAR (GPS) is the USA’s GNSS constellation. Galileo is the EU’s. Previously GPS signals were deprecated which was called “selective availability.” Since 2000, full GPS signals are available to the public. What matters is the receiver and what frequencies it can receive, not the signals themselves.

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