NTP question

Thu May 2 20:35:45 UTC 2019

> But wait. What is the GPS constellation goes down? 
> THEN we have bigger problems :)
> --------------------------------------------------
> 
> 
> What if the US military intentionally messes with 
> the signal to thwart the advances of an enemy who 
> is using GPS in their attack?  ;-)
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--- mel at beckman.org wrote:

Enemies aren’t dependent on US GPS, by the way. lol!
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Oops, but still from the second link: "...which could 
be disabled or degraded by their operators at any time"

Most big countries say the same: "...will provide an 
alternative global navigation satellite system..."

scott

Details for the intrested.

https://en.wikipedia.org/wiki/GLONASS

"Russian...provides an alternative to GPS and is the 
second navigational system in operation with global 
coverage and of comparable precision. 

https://en.wikipedia.org/wiki/Galileo_(satellite_navigation)

"...live in 2016,[4] created by the European Union"
"...so European nations do not have to rely on the 
U.S. GPS, or the Russian GLONASS systems, which could 
be disabled or degraded by their operators at any time"

https://en.wikipedia.org/wiki/BeiDou

"a Chinese satellite navigation system....Beidou-1 was 
decommissioned at the end of 2012."
"BeiDou-2, became operational in China in December 2011 
with a partial constellation of 10 satellites in orbit.
Since December 2012, it has been offering services to 
customers in the Asia-Pacific region."
"In 2015, China started the build-up of the third 
generation BeiDou system (BeiDou-3) for global coverage 
constellation. The first BDS-3 satellite was launched on 
30 March 2015.[5] As of October 2018, fifteen BDS-3 
satellites have been launched[6]. BeiDou-3 will 
eventually consist of 35 satellites and is expected to 
provide global services upon completion in 2020. When 
fully completed, BeiDou will provide an alternative 
global navigation satellite system to the United States 
owned Global Positioning System (GPS),[7][8] the Russian 
GLONASS or European Galileo systems and is expected 
to be more accurate than these

https://en.wikipedia.org/wiki/Indian_Regional_Navigation_Satellite_System

"...is an autonomous regional satellite navigation 
system that provides accurate real-time positioning 
and timing services.[4] It covers India and a region 
extending 1,500 km (930 mi) around it, with plans for 
further extension."

https://en.wikipedia.org/wiki/Quasi-Zenith_Satellite_System

"...a project of the Japanese government for the 
development of a four-satellite regional time transfer 
system and a satellite-based augmentation system for the 
United States operated Global Positioning System (GPS) 
to be receivable in the Asia-Oceania regions, with a 
focus on Japan.