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A comment on The World Economy Runs on GPS. It Needs a Backup Plan. Parent comment

Re:The World Economy Runs on GPS. It Needs a Backup Plan by thermodynthrway on Thursday July 26, 2018 @01:15AM (#17615216)
Yes. Look at the ham hobby, hardly any of them can pick up GPS signals, despite the technology being literally everywhere
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Re:The World Economy Runs on GPS. It Needs a Backup Plan by oh_sigh on Thursday July 26, 2018 @01:39AM (#17615282)
That's not true at all. You can use a $20 SDR card to receive GPS signals and and then can decode them on any commodity laptop, or a small computer like a raspberry pi.

e.g. https://www.rtl-sdr.com/receiving-gps-with-an-rtl-sdr-dongle...

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Re:The World Economy Runs on GPS. It Needs a Backup Plan by berti on Thursday July 26, 2018 @02:15AM (#17615403)
Receiving the signals is only a part of the problem, and even getting a "fix" isn't all that hard. Maintaining an accurate fix, and at the same time refining away previous errors, on a fast moving vehicle, is a dark art.
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Re:The World Economy Runs on GPS. It Needs a Backup Plan by londons_explore on Thursday July 26, 2018 @03:07AM (#17615599)
Software architectures are the limiting factor here.

Every app on your phone cares about "Where am I now", but no app wants to know "Where was I 5 seconds ago, but with more accuracy than you knew when I last asked".

Neither android not iPhone have an API to allow GPS hardware to refine the accuracy of historic position locations.

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Re:The World Economy Runs on GPS. It Needs a Backup Plan by thermodynthrway on Thursday July 26, 2018 @01:42AM (#17615295)
Possible maybe but unusual. 99% of ham is narrowband, GPS is spread across a megahertz. Somebody goofed and made a TV tuner chip that could be used as an SDR at that sample rate, and I'm sure the powers that be arent happy.
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Re:The World Economy Runs on GPS. It Needs a Backup Plan by Johnythree on Thursday July 26, 2018 @09:31AM (#17617288)
You what?

Any sensitive Spectrum Analyser or SDR can see the bump in the spectrum caused by the GPS Signals. And quite a few amateurs have built homebrew GPS receivers.

Or they can buy a little GPS module and use the data stream for a huge range of projects.

Most modern digital Ham communication methods require a 10MHz feed from a GPS module to maintain sufficient time and frequency accuracy.

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