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'We've bought the wrong satellites': UK tech gamble baffles experts

theguardian.com

1–10 of 17 posts

Re: 'We've bought the wrong satellites': UK tech gamble baffles experts

#2
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.

Re: 'We've bought the wrong satellites': UK tech gamble baffles experts

#3

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 t…

How do you add an atomic clock to a satellite that is already in orbit ?

Re: 'We've bought the wrong satellites': UK tech gamble baffles experts

#4

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 t…

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.

Re: 'We've bought the wrong satellites': UK tech gamble baffles experts

#5
>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

Re: 'We've bought the wrong satellites': UK tech gamble baffles experts

#6
post #3

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 t…

How do you add an atomic clock to a satellite that is already in orbit ?

By upgrading the firmware of course. This is clearly a problem for the software dept to solve.

Re: 'We've bought the wrong satellites': UK tech gamble baffles experts

#8
post #6
post #3

Earlier quoted context omitted.

How do you add an atomic clock to a satellite that is already in orbit ?

By upgrading the firmware of course. This is clearly a problem for the software dept to solve.

> By upgrading the firmware ...

... to include atomic operations.

Re: 'We've bought the wrong satellites': UK tech gamble baffles experts

#9
post #5

>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…

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.

Re: 'We've bought the wrong satellites': UK tech gamble baffles experts

#10
post #5

>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…

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 'h…

>small extra step of adding [...] an antenna

That's where the ducktape comes in I guess? (Just kidding)

I mean yeah GPS is ancient tech. But actually getting the required 24 or whatever satellites into orbit (or retrofitting) and getting the receiver tech into enough hands to get any kind of traction is still a sizable challenge.

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