GPS Selective Availability

Discussions focus on the historical US policy of Selective Availability that intentionally degraded civilian GPS accuracy, its discontinuation in 2000, and comparisons to other GNSS systems like GLONASS, Galileo, and BeiDou as backups or alternatives.

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Keywords

e.g US radioshack.com DOP state.edu gps.html ELI5 en.m DGPS GPS gps galileo satellites signal availability selective accuracy signals satellite precision

Sample Comments

jonknee Jul 14, 2017 View on HN

They share GPS, it used to be low-res but is now the real deal:https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_...

lxgr Oct 21, 2022 View on HN

Selective Availability being phased out and is no longer a feature on the most recent GPS satellites:https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_...

fanf2 Nov 15, 2020 View on HN

You are thinking of “selective availability” which was turned off over 20 years ago https://www.gps.gov/systems/gps/modernization/sa/

Asraelite Mar 22, 2018 View on HN

By "another GPS" do you mean a different satellite in the same network, or a different GNSS?

toomuchtodo Dec 3, 2024 View on HN

Any insight as to why newer GPS satellites do not offer similar capabilities?

manarth Nov 4, 2017 View on HN

The feature is called "Selective Availability", and has been disabled since May 2000.https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_...

Natsu Nov 18, 2011 View on HN

Doesn't the government add a small amount of variance to the GPS signal to limit its accuracy for non-military users? Or did they stop doing that?

Laremere Jun 3, 2023 View on HN

GPS had this capability, and it was turned off: https://en.m.wikipedia.org/wiki/Error_analysis_for_the_Globa...

savimportweb Jul 25, 2018 View on HN

GPS is american, Europeans have the Galileo system, and the russians have glonass. aren't those a backup plan

rlanday Sep 22, 2017 View on HN

Civilian GPS signals used to have intentional error added, but that was ended in 2000:https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_...