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  • DAVID MITLYNG

Weekly Takeaways-November 21, 2022

Theme of the Week

A Sputnik Moment The new space race is underway, and in many respects China has taken a lead. China is the clear leader in quantum satellites as shown in this list compiled by Russ Fein. They performed ground-breaking quantum experiments on their 2016 Micius satellite, and recently launched their third quantum satellite with more on the way. While the US has one quantum payload in orbit, it does not have a quantum link with the ground. This is well behind quantum satellites already underway in China, Europe, Singapore, Canada, and UK. At least the US is the leader in position, navigation and timing (PNT) satellites - for now. While GPS has been the PNT standard for nearly five decades, China is catching up fast.

Their BeiDou constellation of “24 MEO satellites, three Geostationary Earth Orbit (GEO) satellites, and three Inclined Geosynchronous Orbit (IGSO) satellites" may offer “global decimeter-level positioning and navigation” and “underwater, indoor and deep space coverage.” This is better than GPS, which is accurate to 2 meters (20 decimeters) in open sky conditions. But clearly the US has a plan to keep up - right? Last Week's Theme: A Modern Horror Story

Achievements


Industry News


Conferences

The More You Know...

Goodbye leap second!

The world’s timekeepers voted recently to stop using leap seconds, an artifice to help keep official time in line with the rotation of the Earth.

If the Earth maintained a rotation rate of 86,400 seconds per day this wouldn’t be necessary.

But the Earth has a habit of slowing down, or, lately, speeding up.

Network operators have longed argued that we should scrap the leap second.

Even a discontinuity as small as one second can wreak havoc with their networks:

“The leap second change triggered a massive Reddit outage in 2012, as well as related problems at Mozilla, LinkedIn, Yelp and airline booking service Amadeus. In 2017, a leap second glitch at network infrastructure company Cloudflare knocked a fraction of customers' servers offline.”

Fortunately, the main source of network timing comes from GPS, which doesn't use leap seconds.

Because of this GPS time has diverged by 18 seconds from Coordinated Universal Time (UTC).

But at least that gap won't change going forward.

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