
'We've bought the wrong satellites': UK tech gamble baffles experts - watbe
https://www.theguardian.com/science/2020/jun/26/satellite-experts-oneweb-investment-uk-galileo-brexit
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h2odragon
So the "trick" to location satellite systems is super accurate and stable
atomic clocks. Each satellite basically pings a timestamp out and you derive
your location from the difference in when you receive which ping from several
satellites.

So the issue would be "how much more expensive is it going to be to equip
these satellites with those clocks?" There might well be enough other uses for
accurate clocks on these to make upgrading whatever they do have worth it.
They might not be that expensive anymore.

Apologies for any misunderstandings im suffering here.

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Junk_Collector
These satellites are likely too small to support a proper positioning system.
They would need the radio transmitters, power system, and clocks all
redesigned at which point you have an entirely new satellite.

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Dylan16807
> power system

I see different size estimates for these satellites but none of them suggest
it would be hard for them to spend 10 watts on an atomic clock and 50 watts on
a constant transmission. Am I forgetting something?

> radio transmitter

You can't just slap on a significantly simpler antenna?

> clocks

I have no idea here.

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jonplackett
The article also fails to mention that OneWeb will probably go bankrupt within
a few years anyway when SpaceX put 100X more satellites in orbit than they
could ever dream of paying for.

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Havoc
>the very talented lobbyists at OneWeb have convinced the government that we
can completely redesign some of the satellites to piggyback a navigation
payload on it.

I mean it's hard not to laugh.

All the major GNSS are herculean focused efforts over decades and the UK
leadership reckons a ducktape solution will do.

They would be better off just negotiating (paying) access to military
encryption on GPS and Galileo and calling it a day. Redundant encrypted is
probably miles better than improvised something anyway

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londons_explore
I disagree. GNSS systems _used_ to be very complex and hard to design.

Times have changed though, and nearly all the components are off-the-shelf
now. If you already have the capability to launch a satellite, adding GNSS
capabilities is a small extra step of adding an atomic clock and an antenna.
All the signal generation can be software defined. All the complexity can live
in models on the ground.

Sure, some of the 'high power anti-jam directional antenna' bits require more
hardware, but the basics do not.

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toomuchtodo
What would the difficulty level be of incorporating GNSS into SpaceX’s
StarLink satellites?

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usrusr
All the active station keeping required for small satellites in low orbits
makes me wonder how much precision would suffer. Perhaps doable but requiring
so much constant self-calibration that quality breaks down in areas without a
network of active reference base stations? It's difficult to guesstimate the
impact with magnitudes so far outside human scale.

