4 ms·

> Flexing the ability to jam GPS is pointless, since it's obvious that any state actor who has military satellites in orbit has considered this option or have t

> Flexing the ability to jam GPS is pointless, since it's obvious that any state actor who has military satellites in orbit has considered this option or have the capability already. Forget "state actors", truck drivers have taken out entire airports with GPS jammers: * https://www.cnet.com/culture/truck-driver-has-gps-jammer-accidentally-jams-newark-airport/ https://www.cnet.com/culture/truck-driver-has-gps-jammer-acc... People like the Resilient Navigation and Timing Foundation have been trying for years to get some kind of GNSS backup accepted: * https://rntfnd.org https://rntfnd.org China has certainly put their money into resiliency (both navigation and timing): * https://www.gpsworld.com/china-completes-national-eloran-network/ https://www.gpsworld.com/china-completes-national-eloran-net... * https://rntfnd.org//2026/03/19/china-has-built-a-triad-of-satellites-towers-and-fibre-to-never-lose-its-way-in-war-india-doesnt-have-one-swarajya/ https://rntfnd.org//2026/03/19/china-has-built-a-triad-of-sa... * https://rntfnd.org/2023/11/28/china-eloran-used-for-critical-infrastructure-extension-to-be-complete-by-2026-new-paper/ https://rntfnd.org/2023/11/28/china-eloran-used-for-critical... Some folks are certainly cluing in: South Korea has (e)Loran and the UK and France are joining up with them: * https://rntfnd.org/2025/04/30/the-uks-system-of-systems-approach-to-robust-pnt-inside-gnss/ https://rntfnd.org/2025/04/30/the-uks-system-of-systems-appr... * https://rntfnd.org/2025/11/12/s-korea-leads-meeting-with-u-k-and-france-on-eloran/ https://rntfnd.org/2025/11/12/s-korea-leads-meeting-with-u-k...

mrngld 4mo ago
The US still has a fairly robust network of VOR's / VOR with DME / VORTAC stations. Good for navigation, but there's no timing component, beyond what's inherent in how they operate. Admittedly, that'll never be of use outside aviation as its line-of-sight only. But if the sun threw a Carrington event (or worse) at us, I think a lot of western aviation could carry on.
- throw0101c 4mo ago
  > The US still has a fairly robust network of VOR's / VOR with DME / VORTAC stations. Good for navigation, but there's no timing component, beyond what's inherent in how they operate. Admittedly, that'll never be of use outside aviation […] I'm aware of the FAA's MON, Minimum Operating Network. Exactly: that doesn't help boats. Or people in cars. Or farmers: * https://www.deere.com/en/technology-products/precision-ag-technology/guidance/ https://www.deere.com/en/technology-products/precision-ag-te... It doesn't help those that use GNSS for precise timing (TCXOes can only 'free run' for a finite amount of time before drift compounds 'too much').
- ifwinterco 4mo ago
  A lot of these were getting dismantled until quite recently, but given recent developments they should obviously be kept
  - throw0101c 4mo ago
    > A lot of these were getting dismantled until quite recently, but given recent developments they should obviously be kept The FAA has always planned for keeping a non-GNSS-based infrastructure: * https://www.faa.gov/air_traffic/flight_info/aeronav/acf/media/Presentations/12-02-Discon_of_VOR_Srvcs_presentation.pdf https://www.faa.gov/air_traffic/flight_info/aeronav/acf/medi... * https://www.federalregister.gov/documents/2012/08/21/2012-20464/proposed-provision-of-navigation-services-for-the-next-generation-air-transportation-system-nextgen https://www.federalregister.gov/documents/2012/08/21/2012-20... * https://download.aopa.org/epilot/2012/120112VOR-MON-White-Paper.pdf https://download.aopa.org/epilot/2012/120112VOR-MON-White-Pa... * https://flighttrainingcentral.com/2017/03/legacy-navigation-systems/ https://flighttrainingcentral.com/2017/03/legacy-navigation-...
bananaowl 4mo ago
Iridium has launched its own alternative positioning and timing system now https://www.iridium.com/iridium-pnt https://www.iridium.com/iridium-pnt
- actionfromafar 4mo ago
  It's wild how far Motorola has fallen.
- throw0101a 4mo ago
  GPS L1 is at 1575 MHz, Iridium is (AFACIT) at 1626 MHz: that's 50 MHz over. * https://gssc.esa.int/navipedia/index.php/GNSS_signal https://gssc.esa.int/navipedia/index.php/GNSS_signal * https://insidegnss.com/something-old-something-new/ https://insidegnss.com/something-old-something-new/ * https://en.wikipedia.org/wiki/Iridium_satellite_constellation https://en.wikipedia.org/wiki/Iridium_satellite_constellatio... If you're jamming on L1 I don't think it's that much more difficult to jam a little bit over as well.
brohee 4mo ago
Celestial Navigation is also doable even in daylight nowadays, e.g. https://sodern.com/en/ranges/astradia https://sodern.com/en/ranges/astradia
- labcomputer 4mo ago
  It's been doable since the 1940's. https://patents.google.com/patent/US2981843A/en https://patents.google.com/patent/US2981843A/en
- throw0101c 4mo ago
  Will that come as an option for my RAV4 or F-150? How about my Cessna? Will it help keep my NTP/PTP masters sync'd?

mrngld 4mo ago

The US still has a fairly robust network of VOR's / VOR with DME / VORTAC stations. Good for navigation, but there's no timing component, beyond what's inherent in how they operate. Admittedly, that'll never be of use outside aviation as its line-of-sight only. But if the sun threw a Carrington event (or worse) at us, I think a lot of western aviation could carry on.

throw0101c 4mo ago
> The US still has a fairly robust network of VOR's / VOR with DME / VORTAC stations. Good for navigation, but there's no timing component, beyond what's inherent in how they operate. Admittedly, that'll never be of use outside aviation […] I'm aware of the FAA's MON, Minimum Operating Network. Exactly: that doesn't help boats. Or people in cars. Or farmers: * https://www.deere.com/en/technology-products/precision-ag-technology/guidance/ https://www.deere.com/en/technology-products/precision-ag-te... It doesn't help those that use GNSS for precise timing (TCXOes can only 'free run' for a finite amount of time before drift compounds 'too much').
ifwinterco 4mo ago
A lot of these were getting dismantled until quite recently, but given recent developments they should obviously be kept
- throw0101c 4mo ago
  > A lot of these were getting dismantled until quite recently, but given recent developments they should obviously be kept The FAA has always planned for keeping a non-GNSS-based infrastructure: * https://www.faa.gov/air_traffic/flight_info/aeronav/acf/media/Presentations/12-02-Discon_of_VOR_Srvcs_presentation.pdf https://www.faa.gov/air_traffic/flight_info/aeronav/acf/medi... * https://www.federalregister.gov/documents/2012/08/21/2012-20464/proposed-provision-of-navigation-services-for-the-next-generation-air-transportation-system-nextgen https://www.federalregister.gov/documents/2012/08/21/2012-20... * https://download.aopa.org/epilot/2012/120112VOR-MON-White-Paper.pdf https://download.aopa.org/epilot/2012/120112VOR-MON-White-Pa... * https://flighttrainingcentral.com/2017/03/legacy-navigation-systems/ https://flighttrainingcentral.com/2017/03/legacy-navigation-...

bananaowl 4mo ago

Iridium has launched its own alternative positioning and timing system now https://www.iridium.com/iridium-pnt https://www.iridium.com/iridium-pnt

actionfromafar 4mo ago
It's wild how far Motorola has fallen.
throw0101a 4mo ago
GPS L1 is at 1575 MHz, Iridium is (AFACIT) at 1626 MHz: that's 50 MHz over. * https://gssc.esa.int/navipedia/index.php/GNSS_signal https://gssc.esa.int/navipedia/index.php/GNSS_signal * https://insidegnss.com/something-old-something-new/ https://insidegnss.com/something-old-something-new/ * https://en.wikipedia.org/wiki/Iridium_satellite_constellation https://en.wikipedia.org/wiki/Iridium_satellite_constellatio... If you're jamming on L1 I don't think it's that much more difficult to jam a little bit over as well.

brohee 4mo ago

Celestial Navigation is also doable even in daylight nowadays, e.g. https://sodern.com/en/ranges/astradia https://sodern.com/en/ranges/astradia

labcomputer 4mo ago
It's been doable since the 1940's. https://patents.google.com/patent/US2981843A/en https://patents.google.com/patent/US2981843A/en
throw0101c 4mo ago
Will that come as an option for my RAV4 or F-150? How about my Cessna? Will it help keep my NTP/PTP masters sync'd?